TW201923884A - Production method for semiconductor device - Google Patents

Abstract

A semiconductor device production method whereby semiconductor devices are produced using an expandable adhesive sheet (A) that has a base material (Y1) and an adhesive layer (X1) and includes expandable particles in one of the layers. The production method includes steps (1)-(3), in order. Step (1): A step in which, after pasting a workpiece on to the adhesive layer (X1) of the adhesive sheet (A), the workpiece is diced and a plurality of chips, being individual pieces, are obtained on the adhesive layer (X1). Step (2): A step in which an adhesive layer (X2) of an adhesive sheet (B) having a base material (Y2) and an adhesive layer (X2) is pasted on to a surface of the plurality of chips that is on the opposite side to the adhesive layer (X1). Step (3): A step in which the expandable particles are expanded and the adhesive sheet (A) and the plurality of semiconductor chips pasted to the adhesive sheet (B) are separated.

Description

Manufacturing method of semiconductor device

The present invention relates to a method for manufacturing a semiconductor device.

In recent years, advances in miniaturization, weight reduction, and high performance of electronic equipment have accompanied the demand for miniaturization, thinness, and high density of semiconductor devices mounted in electronic equipment.
Semiconductor wafers have packages that are mounted close to their size. Such a package is also called a CSP (Chip Scale Package). Examples of the CSP include: WLP (Wafer Level Package) that completes the process to the final package process at the wafer size, and PLP (Wafer Level Package) that completes the process to the final package process at a wafer size larger than the wafer size Panel Level Package).

WLP and PLP are classified into Fan-In type and Fan-Out type. In the fan-out type WLP (hereinafter, also referred to as "FOWLP") and PLP (hereinafter, also referred to as "FOPLP"), semiconductor wafers are formed in a range larger than the wafer size, and closed materials It is covered to form a semiconductor wafer closed body, and a redistribution layer or an external electrode is formed not only on the circuit surface of the semiconductor wafer but also on the surface of the sealing material.
For example, Patent Document 1 describes a semiconductor wafer in which a plurality of semiconductor wafers are singulated, a circuit forming surface is left, an expansion wafer is formed around the periphery using a model member, and a range outside the semiconductor wafer is provided. , A manufacturing method of a semiconductor package formed by extending a redistribution pattern. In the manufacturing method described in Patent Document 1, a semiconductor wafer is subjected to a dicing process in which the wafer is diced in a state where it is attached to a wafer mounting tape for dicing (hereinafter, also referred to as a "dicing tape"). The plurality of semiconductor wafers obtained in this dicing process are transferred to a wafer mounting tape for expansion (hereinafter, also referred to as an "expansion tape"). The plurality of semiconductor wafers are extended by extending the expansion tape. Expansion project for distance extension.

The dicing tape is used in the manufacturing process of a semiconductor device, and is used to singulate a processed object represented by a singulated semiconductor wafer. A certain adhesive force is required in order to suppress peeling of the processed object and position shift during dicing. On the other hand, it is required to have a detachability for easily separating individual wafers after dicing.
As a dicing tape which improves the release property after dicing, Patent Document 2 discloses that a dicing tape having a base material and an adhesive layer is used as a material of the adhesive layer, which is hardened by UV irradiation and the adhesive force is reduced.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] International Publication No. 2010/058646
[Patent Document 2] Japanese Patent Laid-Open No. 2016-167510

[Questions to be Solved by the Invention]

However, after the dicing tape described in Patent Document 2 is irradiated with ultraviolet rays, the wafer and the adhesive layer are also adhered to the entire adhesive surface, and a certain degree of adhesive force remains. Therefore, when a wafer obtained by dicing is provided in a subsequent process, it may become complicated to select a wafer or the like for each process.

Moreover, in the manufacturing process of a fan-out package, as described in the manufacturing method of patent document 1, the semiconductor wafer obtained by dicing may be moved to an expansion tape.
The aforementioned movement is a method of directly transferring a semiconductor wafer from a dicing tape to an expansion tape, and a method of transferring a semiconductor wafer from a dicing tape to another adhesive sheet, and then transferring from the other adhesive sheet to the expansion tape. However, in any case, it is preferable to transfer a plurality of semiconductor wafers from the viewpoint of productivity.
However, if the dicing tape described in Patent Document 2 still has a certain degree of adhesive force after UV irradiation, a certain external force is required to separate the dicing tape from the semiconductor wafer, and it is necessary to separate the tape. Complicated device.
In addition, there is a load on the semiconductor wafer during separation, and it is easy to cause problems such as positional deviation and wafer defects on the semiconductor wafer.

The present invention has a structure made in view of the above-mentioned problems, and an object thereof is to provide that a plurality of wafers obtained by cutting a workpiece can be easily transferred to another adhesive sheet, and can effectively suppress the aforementioned transfer. A method of manufacturing a semiconductor device that generates a wafer defect at the time of printing.

[Means for solving problems]

The present inventors have found that by using a method of manufacturing a semiconductor device having a base material and an adhesive layer and an expandable adhesive sheet containing expandable particles in any one of the layers, there are specific processes (1) to (3) ) Can solve the above problems.
That is, the present invention relates to the following [1] to [11].
[1] A method for manufacturing a semiconductor device, which is a method for manufacturing a semiconductor device having a base material (Y1) and an adhesive layer (X1), and containing expandable particles in any of the layers and using an expandable adhesive sheet (A) Among them, there is a method for manufacturing a semiconductor device in the order of the following processes (1) to (3).
Process (1): After attaching the processed object to the adhesive layer (X1) of the adhesive sheet (A), cutting the processed object to obtain a plurality of wafers that are sliced on the adhesive layer (X1) .
Process (2): using an adhesive sheet (B) having a base material (Y2) and an adhesive layer (X2), attaching the adhesive on the side opposite to the surface to which the adhesive layer (X1) of the plurality of wafers is bonded Process of adhesive layer (X2) of sheet (B).
Process (3): A process of expanding the expandable particles and separating the plurality of wafers and the adhesive sheet (A) attached to the adhesive sheet (B).
[2] The method for manufacturing a semiconductor device according to the above [1], wherein the adhesive sheet (B) is an adhesive sheet for expansion, and after the process (3), it further has the following process (4A).
Process (4A): The process of stretching and expanding the adhesive sheet (B) at intervals between the plurality of wafers attached to the adhesive sheet (B).
[3] The method for manufacturing a semiconductor device according to the above [1], wherein the following process is further performed using an adhesive sheet (C) for expansion having a substrate (Y3) and an adhesive layer (X3) ( 4B-1) ~ (4B-3).
Process (4B-1): Process for attaching the adhesive layer (X3) of the adhesive sheet (C) on the side opposite to the surface to which the adhesive layer (X2) of the plurality of wafers on the adhesive sheet (B) is bonded .
Process (4B-2): The process of separating the adhesive sheet (B) from a plurality of wafers attached to the adhesive sheet (C).
Process (4B-3): The process of stretching and expanding the adhesive sheet (C) between the plurality of wafers attached to the adhesive sheet (C).
[4] The method for manufacturing a semiconductor device according to the above [2] or [3], wherein the adhesive sheet for expansion described above is 100% at an elongation at break measured in the MD direction and the CD direction at 23 ° C. the above.
[5] The method for manufacturing a semiconductor device according to any one of the above [1] to [4], wherein the expandable particles are thermally expandable particles having an expansion start temperature (t) of 60 to 270 ° C, and the aforementioned process (3) The process of separating the plurality of wafers attached to the adhesive sheet (B) and the adhesive sheet (A) by heating the adhesive sheet (A).
[6] The method for manufacturing a semiconductor device according to any one of the above [1] to [5], wherein the process (1) includes a process of stretching the adhesive sheet (A) after cutting the object to be processed.
[7] The method for manufacturing a semiconductor device according to any one of the above [1] to [6], wherein the expandable particles adhere to the adhesive layer (X1) of the sheet (A) at 23 ° C before expansion. The adhesive force is 0.1 ~ 10.0N / 25mm.
[8] The method for manufacturing a semiconductor device according to any one of the above [1] to [7], wherein the probe adhesion value on the surface of the substrate (Y1) of the adhesive sheet (A) is less than 50 mN / 5 mmf.
[9] The method for manufacturing a semiconductor device according to any one of the above [1] to [8], wherein the base material (Y1) included in the adhesive sheet (A) is an expandable base material containing the expandable particles ( Y1-1).
[10] The method for manufacturing a semiconductor device according to any one of the above [1] to [9], wherein the processed object is a semiconductor wafer.
[11] The method for manufacturing a semiconductor device according to the above [10], wherein the method is a method for manufacturing a fan-out type semiconductor device.

Invention effect

According to the present invention, it is possible to provide a semiconductor device that can easily transfer a plurality of wafers obtained by cutting a workpiece to another adhesive sheet, and can effectively suppress the occurrence of wafer defects during transfer. Method.

In this specification, "active ingredient" means a component contained in a target composition, except a component that dilutes a solvent.
The mass average molecular weight (Mw) is a value measured in terms of a standard polystyrene by a gel permeation chromatography (GPC) method, and specifically a value measured by a method described in Examples.

In this specification, for example, the expression "(meth) acrylic acid" means both "acrylic acid" and "methacrylic acid", and other similar terms are the same.
In addition, with respect to an ideal numerical range (for example, a range of the content and the like), the lower limit value and the upper limit value described in stages may be independently combined. For example, from the description of "ideal system 10 to 90, more ideal system 30 to 60", combining "ideal lower limit value (10)" and "ideal upper limit value (60)", and also "10 to 60" can.

In this specification, "wafer transfer" means that the surface of the wafer attached to one of the adhesive sheets is adhered to the other adhesive sheet, and then the one adhesive sheet is separated from the wafer. The operation of moving the wafer from one adhesive sheet to the other adhesive sheet.

A method for manufacturing a semiconductor device according to this embodiment is a method for manufacturing a semiconductor device including a base material (Y1) and an adhesive layer (X1), which contain expandable particles in either layer, and which uses an expandable adhesive sheet (A). Among them, those who have the following procedures (1) to (3).
Process (1): After attaching the processed object to the adhesive layer (X1) of the adhesive sheet (A), cutting the processed object to obtain a plurality of wafers that are sliced on the adhesive layer (X1) .
Process (2): using an adhesive sheet (B) having a base material (Y2) and an adhesive layer (X2), attaching the adhesive on the side opposite to the surface to which the adhesive layer (X1) of the plurality of wafers is bonded Process of adhesive layer (X2) of sheet (B).
Process (3): A process of expanding the expandable particles and separating the plurality of wafers and the adhesive sheet (A) attached to the adhesive sheet (B).
Examples of the object system used in this embodiment include semiconductor devices including semiconductor wafers, LEDs (Light Emitting Diodes), MEMS (Micro Electro Mechanical Systems), ceramic devices, semiconductor packages, and multiple devices. Cut processing in manufacturing processes.
In addition, in this specification, "wafer" means the person who slice | divided the said to-be-processed object.
Hereinafter, the adhesive sheet (A) used in the manufacturing method of this embodiment will be described first, and then each manufacturing process including processes (1) to (3) will be described.

[Adhesive sheet (A)]
The adhesive sheet (A) is a swellable adhesive sheet having a base material (Y1) and an adhesive layer (X1), and each layer contains expandable particles.
The adhesive sheet (A) is used to firmly fix the workpiece through the adhesive surface of the adhesive layer (X1) before expanding the expandable particles. In the cutting process of the workpiece, it is possible to suppress the workpiece. The position is shifted and the cutter is performed with good workability.
On the other hand, when separating the adhesive sheet (A) from the wafer obtained by cutting the workpiece, the unevenness is formed on the adhesive surface of the adhesive layer (X1) by expanding the expandable particles, and then the adhesive is passed therethrough. The contact area between the adhesive surface of the layer (X1) and the wafer is reduced, and the adhesion force can be reduced compared to the conventional UV-curable dicing tape. As a result, a plurality of wafers obtained by dicing can be easily transferred to another adhesive sheet collectively without requiring complicated manufacturing equipment, and the positional deviation of wafers and wafer defects can be suppressed at this time. By.
In addition, when the adhesive sheet (A) is separated from the wafer, when the adhesive sheet (A) is partially heated, not all the wafers obtained by dicing may be selectively separated from the obtained wafers. Part of the chipper. Specifically, a form in which a plurality of wafers obtained by dicing are divided into a plurality of units and transferred to another adhesive sheet in each unit is mentioned.

1 (a) and 1 (b) are schematic cross-sectional views of an adhesive sheet 1a and an adhesive sheet 1b in the form of one of the adhesive sheets (A).
In one aspect of the present invention, if the adhesive sheets 1a, 1b are used, the base material (Y1) is preferably an expandable base material (Y1-1) containing expandable particles.

The adhesive sheet 1a shown in FIG. 1 (a) is on one side of the substrate (Y1-1), and has an adhesive layer (X1). The adhesive sheet 1a is formed by attaching a workpiece to the adhesive layer (X1), cutting the workpiece to obtain a plurality of wafers, and separating the wafers. The separation of the adhesive sheet 1a from the wafer can be easily performed by causing the unevenness on the surface bonded to the wafer of the adhesive layer (X1) by expanding the expandable particles in the substrate (Y1-1). Separation at the interface between the adhesive layer (X1) and the wafer.

The adhesive sheet 1b shown in FIG. 1 (b) is on one side of the substrate (Y1-1) and has an adhesive layer (X1), and on the other side, has a non-swellable substrate (Y1 '). . The adhesive sheet 1b is the same as the user of the adhesive sheet 1a, but when the expandable particles in the substrate (Y1-1) are expanded, the presence of a non-expandable substrate (Y1 ') can suppress the substrate. The unevenness on the surface of the non-expandable base material (Y1 ') side of the material (Y1-1) can be formed more efficiently through the unevenness on the surface of the adhesive layer (X1).

The constitution of the adhesive sheet (A) is not limited to the constitution shown in Figs. 1 (a) and (b), but, for example, the substrate (Y1) ((Y1-1) in Fig. 1) and the adhesive A structure having other layers between the layers (X1) may be used. However, from the viewpoint of being an adhesive sheet that can be separated with a slight force, it is preferable to have a constitution in which a substrate (Y1) and an adhesive layer (X1) are directly laminated. In addition, a configuration having another adhesive layer on the surface on the side opposite to the adhesive layer (X1) of the base material (Y1) may be used.
The adhesive sheet (A) is attached to the adhesive layer (X1), and may have a release material. The release material is suitably peeled and removed when the adhesive sheet (A) is used in the manufacturing method according to this embodiment.
The shape of the adhesive sheet (A) can be all shapes such as sheet, tape, and label.

(Expansive particles)
The adhesive sheet (A) is a layer containing any one of the base material (Y1) and the adhesive layer (X1), and contains expandable particles.
The expandable particles are not particularly limited as long as they are swelled by external stimuli, and they form irregularities on the adhesive surface of the adhesive layer (X1), which can reduce the adhesion force to the adherend.
Examples of the expandable particle system include thermally expandable particles that expand by heating and energy ray expandable particles that expand by energy ray irradiation, but thermal expandable particles are preferred from the viewpoints of versatility and handling. .

The expansion start temperature (t) of the thermally expandable particles is preferably 60 to 270 ° C, more preferably 70 to 260 ° C, and still more preferably 80 to 250 ° C.
However, in this specification, the expansion start temperature (t) of a thermally expandable particle means the value measured by the following method.

[Method for measuring the expansion start temperature (t) of thermally expandable particles]
An aluminum cup with a diameter of 6.0 mm (inner diameter of 5.65 mm) and a depth of 4.8 mm was prepared, and 0.5 mg of the thermally expansive particles to be measured were added, and a sample with an aluminum lid (5.6 mm in diameter and 0.1 mm in thickness) was placed from above.
A movable viscoelasticity measuring device was used. In this sample, the height of the sample was measured from the upper part of the aluminum cover through a state in which a force of 0.01 N was applied. In addition, in a state where a force of 0.01 N is applied through the pressurizer, heating is performed at a temperature increase rate of 10 ° C / min from 20 ° C to 300 ° C, and the displacement in the vertical direction of the pressurizer is measured. The temperature at which the displacement started was taken as the expansion start temperature (t).

A thermally expandable particle is preferably made of an outer shell made of a thermoplastic resin, and a microencapsulated foaming agent which is contained in the outer shell and is formed by an inner component that vaporizes when heated to a specific temperature.
Examples of the thermoplastic resins constituting the shell of the microencapsulated foaming agent include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, and polypropylene Nitrile, polyvinylidene chloride, polyfluorene, etc.

Examples of the internally enclosed components included in the outer shell include propane, butane, n-pentane, hexane, heptane, octane, nonane, decane, isobutane, isopentane, and isohexane. , Isoheptane, isooctane, isononane, isodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, neopentane, dodecane, isodes Dioxane, cyclododecane, cyclotridecane, hexylcyclohexene, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, isotridecane , 4-methyldodecane, isotetradecane, isopentadecane, isohexadecane, 2,2,4,4,6,8,8-heptamethylnonane, isoheptadecane, iso Octadecane, isacosane, 2,6,10,14-tetramethylpentadecane, cyclotridecane, heptylcyclohexane, n-octylcyclohexane, cyclopentadecane, nonyl Cyclohexane, decylcyclohexane, pentadecylcyclohexane, cetylcyclohexane, heptadecylcyclohexane, octadecylcyclohexane, and the like. These inclusion ingredients may be used alone or in combination of two or more.
The expansion start temperature (t) of the thermally expandable particles can be adjusted by appropriately selecting the type of the contained component.

The maximum volume expansion rate when heated to a temperature above the thermal expansion start temperature (t) of the thermally expandable particles is preferably 1.5 to 100 times, more preferably 2 to 80 times, still more preferably 2.5 to 60 times, and more Ideally, it is 3 to 40 times.

The average particle diameter of the expandable particles at 23 ° C before expansion is preferably 3 to 100 μm, more preferably 4 to 70 μm, still more preferably 6 to 60 μm, and even more preferably 10 to 50 μm.
However, the average particle diameter before the expansion of the swellable particles refers to the volume median particle diameter (D ₅₀ ), which means that it is measured using a laser particle size analyzer (for example, manufactured by Malvern, product name "Mastersizer-3000"). In the particle distribution of the expandable particles before expansion, the cumulative volume frequency calculated from the smaller particle diameter of the expandable particles before expansion is equivalent to 50% of the particle diameter.

The 90% particle diameter (D ₉₀ ) of the expandable particles at 23 ° C before expansion is preferably 10 to 150 μm, more preferably 20 to 100 μm, still more preferably 25 to 90 μm, and still more preferably 30 to 80 μm.
However, the 90% particle diameter (D ₉₀ ) of the expandable particles before expansion means that the particle size is measured using a laser particle size analyzer (for example, manufactured by Malvern, product name "Mastersizer-3000"), and the expansion before expansion is measured. In the particle distribution of the expansive particles, the cumulative volume frequency calculated from the smaller particle diameter of the expansive particles before self-expansion is 90% of the particle diameter.

The content of the expandable particles is preferably 1 to 40% by mass, more preferably 5 to 35% by mass, and even more preferably 10 to the total amount (100% by mass) of the effective components of the layer containing the expandable particles. ~ 30% by mass, and even more preferably 15 ~ 25% by mass.

(Substrate (Y1))
The (substrate (Y1)) possessed by the adhesive sheet (A) is a non-adhesive substrate.
In the present invention, the judgment of whether the substrate is non-adhesive is for the surface of the target substrate. If the probe adhesion value measured according to JIS Z0237: 1991 is less than 50mN / 5mmf, the substrate is measured. The material was judged as "non-adhesive base material".
Here, the probe adhesion value on the surface of the substrate (Y1) used in this embodiment is usually less than 50mN / 5mmf, but it is preferably less than 30mN / 5mmf, more preferably less than 10mN / 5mmf, and more preferably less than 5mN. / 5mmf.
However, in this specification, the specific measurement method of the probe adhesion value of the surface of a base material (Y1) is the method described in an Example.

The thickness of the substrate (Y1) is preferably 10 to 1000 μm, more preferably 20 to 500 μm, still more preferably 25 to 400 μm, and still more preferably 30 to 300 μm.
However, in this specification, the thickness of a substrate means the value measured by the method described in an Example.

The base material (Y1) can be formed from a resin composition (y1). Hereinafter, each component of the resin composition (y1) which contains the forming material of a base material (Y1) is demonstrated.

[Resin]
The resin-based substrate (Y1) contained in the resin composition (y1) is not particularly limited as long as it is a non-adhesive resin, and may be a non-adhesive resin or an adhesive resin. That is, even if the resin contained in the resin composition (y1) is an adhesive resin, during the process of forming the substrate (Y1) from the resin composition (y1), the adhesive resin undergoes a polymerization reaction with a polymerizable compound. The obtained resin becomes a non-adhesive resin, and the substrate (Y1) containing the resin may be non-adhesive.

The mass average molecular weight (Mw) of the aforementioned resin contained in the resin composition (y1) is preferably 10 to 1 million, more preferably 10 to 700,000, and still more preferably 10 to 500,000.
In the case where the resin has a copolymer of two or more constituent units, the morphology of the copolymer is not particularly limited, and may be any of a block copolymer, a random copolymer, and a graft copolymer.

The content of the aforementioned resin is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and even more preferably 65 to 95% of the total amount (100% by mass) of the effective components of the resin composition (y1). 90% by mass, and more preferably 70 to 85% by mass.

The resin type contained in the resin composition (y1) preferably contains one or more types selected from the group consisting of acrylic urethane resin and olefin resin. An acrylic urethane-based resin-based polymer urethane prepolymer (UP) and an acrylic urethane-based resin (U1) made of a vinyl compound containing (meth) acrylate are preferred. However, these resin systems are particularly preferable when the resin composition (y1) contains swellable particles, from the viewpoint of swellability.

[Acrylic urethane resin (U1)]
Examples of the urethane prepolymer (UP) that becomes the main chain of the acrylic urethane-based resin (U1) include a reaction product of a polyol and a polyvalent isocyanate.
However, the urethane prepolymer (UP) is preferably a composition obtained by further applying a chain extension reaction using a chain extender.

Examples of the polyols that are used as raw materials for the urethane prepolymer (UP) include alkyl polyols, ether polyols, ester polyols, esteramine polyols, and ester / ether types Polyols, carbonate-type polyols, etc.
These polyols may be used alone or in combination of two or more.
Polyol diols used in this embodiment are preferred, and ester diols, alkyl diols, and carbonate diols are more preferred, and ester diols and carbonate diols are more preferred. good.

Examples of the ester-type diols include those selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. Alkanediols; Alkyl glycols of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, etc .; 1 or 2 or more types of glycols, and selected from phthalic acid, isophthalic acid, Terephthalic acid, naphthalene dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid , Chlorobridged acid, maleic acid, fumaric acid, itaconic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, hexahydrophthalic acid, hexahydroisophthalic acid Condensation polymer of one or two or more kinds of dicarboxylic acids such as dicarboxylic acid, hexahydroterephthalic acid, methylhexahydrophthalic acid, and the like anhydrides.
Specific examples include polyethylene adipate diol, polybutene adipate diol, polycyclohexane adipate diol, polycyclohexane isophthalate diol, and polyneopentyl. Adipic acid diol, polyethylene propylene adipic acid diol, polyethylene butene adipic acid diol, polybutene cyclohexane adipate diol, polydiethylene adipate diol, poly (polytetraethylene Methylene ether) adipic acid diol, poly (3-methylpentadiene) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutene azelate Diol, polybutene sebacate diol, poly neopentyl terephthalate diol, etc.

Examples of the alkyl-based diols include alkane such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. Glycols; Alkyl glycols of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, etc .; Polyolefin glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol; polytetramethylene glycol, etc. Of polyoxyalkylene glycol; etc.

Examples of the carbonate-based diol system include 1,4-tetramethylene carbonate diol, 1,5-pentamethylene carbonate diol, and 1,6-hexamethylene carbonate di Alcohol, 1,2-propylene carbonate diol, 1,3-propylene carbonate diol, 2,2-dimethylpropylene carbonate diol, 1,7-cycloheptane carbonate diol, 1,8 -Octyl carbonate diol, 1,4-cyclohexane carbonate diol, etc.

Examples of the polyvalent isocyanate to be a raw material of the urethane prepolymer (UP) include aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate.
These polyvalent isocyanates may be used alone or in combination of two or more.
In addition, these polyvalent isocyanates can also be trimethylolpropane adduct-type modified products, biurea-type modified products that react with water, and isocyanurate-type modified products containing isocyanurate rings. .
Among these, a polyvalent isocyanate-based diisocyanate used in this embodiment is preferred, and it is selected from 4,4'-diphenylmethane diisocyanate (MDI) and 2,4-toluene diisocyanate (2,4 -TDI), 2,6-toluene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI), and more than one type of alicyclic diisocyanate are more preferable.

Examples of the alicyclic diisocyanate include 3-isocyanatomethylene-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), and 1,3-cyclopentane. Alkane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, etc. , But isophorone diisocyanate (IPDI) is preferred.

In this embodiment, as a reactant between a urethane prepolymer (UP) diol and a diisocyanate, which is the main chain of the acrylic urethane resin (U1), it has ethylenic properties at both ends Unsaturated linear urethane prepolymers are preferred.
Examples of a method for introducing an ethylenically unsaturated group at both ends of the linear urethane prepolymer include a linear urethane prepolymer made of a diol and a diisocyanate compound. A method for reacting a terminal NCO group with a hydroxyalkyl (meth) acrylate.
Examples of hydroxyalkyl (meth) acrylates include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-hydroxypropyl (meth) Acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like.

As a vinyl compound which becomes a side chain of an acrylic urethane-based resin (U1), it contains at least a (meth) acrylate.
The (meth) acrylate is preferably one or more selected from alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate, and an alkyl (meth) acrylate and a hydroxyalkyl ( Methacrylate is more preferred.
When an alkyl (meth) acrylate and a hydroxyalkyl (meth) acrylate are used together, for 100 mass parts of the alkyl (meth) acrylate, it is used as the mixing ratio of the hydroxyalkyl (meth) acrylate The department ideal is 0.1 to 100 mass points, more preferably 0.5 to 30 mass points, more preferably 1.0 to 20 mass points, and even more preferably 1.5 to 10 mass points.

The carbon number of the alkyl group in the alkyl (meth) acrylate is preferably from 1 to 24, more preferably from 1 to 12, still more preferably from 1 to 8, and even more preferably from 1 to 3.
Examples of the hydroxyalkyl (meth) acrylates are the same as the hydroxyalkyl (meth) acrylates used at both ends of the linear urethane prepolymer based on the linear unsaturated urethane prepolymer described above for the introduction of ethylenic unsaturation. Of the composition.

Examples of vinyl compounds other than (meth) acrylates include aromatic hydrogenated vinyl compounds such as styrene, α-methylstyrene, vinyl toluene, and the like; methyl vinyl ether, and ethyl vinyl Vinyl ethers such as vinyl ethers; vinyl acetate, vinyl propionate, (meth) acrylic acid, N-vinyl pyrrolidone, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, methyl (propylene Fluorene) and other polar group-containing monomers; etc.
These systems may be used alone or in combination of two or more.

The content of the (meth) acrylate in the ethylene compound is preferably from 40 to 100% by mass, more preferably from 65 to 100% by mass, and more preferably from the total amount (100% by mass) of the ethylene compound. It is 80 to 100% by mass, and more preferably 90 to 100% by mass.
As the total content of the alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate in the ethylene compound, the total content (100% by mass) of the ethylene compound is preferably 40 to 100% by mass, It is more preferably 65 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass.

The acrylic urethane resin (U1) based urethane prepolymer (UP) and the (meth) acrylate-containing ethylene compound used in this embodiment are obtained by polymerizing both. .
In this polymerization, it is preferable to carry out by adding a radical initiator.

In the acrylic urethane resin (U1) used in this embodiment, the constituent unit (u11) derived from the urethane prepolymer (UP) and the constituent unit (u12) derived from the ethylene compound are used. The content ratio [(u11) / (u12)] is based on mass ratio, ideally 10/90 ~ 80/20, more preferably 20/80 ~ 70/30, and more preferably 30/70 ~ 60/40, Another ideal is 35/65 ~ 55/45.

[Olefin resin]
As the resin contained in the resin composition (y1), the most preferable olefin-based resin is a polymer having at least a constituent unit derived from an olefin monomer.
The α-olefin having 2 to 8 carbon atoms in the above-mentioned olefin single system is preferred, and specifically, ethylene, propylene, butene, isobutylene, 1-hexene, and the like are mentioned.
Among these, ethylene and propylene are preferred.

Specific examples of the olefin-based resin system include ultra-low density polyethylene (VLDPE, density: 880 kg / m ³ or more and less than 910 kg / m ³ ), and low-density polyethylene (LDPE, density: 910 kg / m ³ or more) , Less than 915kg / m ³ ), medium density polyethylene (MDPE, density: 915kg / m ³ or more, less than 942kg / m ³ ), high density polyethylene (HDPE, density: 942kg / m ³ or more), low linearity Polyethylene resin such as density polyethylene; polypropylene resin (PP); polybutene resin (PB); ethylene-propylene copolymer; olefinic elastomer (TPO); poly (4-methyl-1-pentene) (PMP); ethylene-vinyl acetate copolymer (EVA); ethylene-vinyl alcohol copolymer (EVOH); olefin-based terpolymers such as ethylene-propylene- (5-ethylidene-2-norberene); Wait.

In this embodiment, the olefin-based resin is a modified olefin-based resin further modified by one or more types selected from acid denaturation, hydroxyl denaturation, and acrylic denaturation.

For example, examples of the acid-denatured olefin-based resin system obtained by subjecting the olefin-based resin to acid denaturation include the above-mentioned non-denatured olefin-based resin obtained by graft polymerization of an unsaturated carboxylic acid or its anhydride Denatured polymer.
Examples of the aforementioned unsaturated carboxylic acid or anhydride thereof include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaric acid, tetrahydrophthalic acid, aconitic acid, (meth) acrylic acid, Maleic anhydride, itaconic anhydride, phthalic anhydride, citraconic anhydride, aconitic anhydride, norbornene dihydric anhydride, tetrahydrophthalic anhydride, etc.
However, unsaturated carboxylic acids or their anhydrides may be used alone or in combination of two or more.

Examples of the acrylic-modified olefin-based resin obtained by subjecting the olefin-based resin to acrylic modification include the above-mentioned non-denatured olefin-based resin in the main chain, and an alkyl (meth) acrylate as a side chain. Denatured polymer formed by graft polymerization.
The carbon number of the alkyl group as the alkyl (meth) acrylate mentioned above is preferably from 1 to 20, more preferably from 1 to 16, and even more preferably from 1 to 12.
As said alkyl (meth) acrylate type, the thing similar to the compound which can be selected as a monomer (a1 ') mentioned later is mentioned, for example.

Examples of the hydroxyl-modified olefin-based resin obtained by subjecting the olefin-based resin to hydroxyl-modification include the above-mentioned non-denatured olefin-based resin in the main chain, and graft polymerization of the hydroxyl compound. Into denatured polymers.
Examples of the hydroxyl-containing compound system include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, Hydroxyalkyl (meth) acrylates such as 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate; vinyl alcohol , Unsaturated alcohols such as allyl alcohol.

[Resins other than propylene polyurethane resin and olefin resin]
In the present embodiment, the resin composition (y1) is within a range that does not impair the effects of the present invention, and may include resins other than propylene polyurethane resins and olefin resins.
Examples of such resins include vinyl resins such as polyvinyl chloride, polyvinylidene chloride, and polyvinyl alcohol; polyethylene terephthalate, polybutylene terephthalate, and polynaphthalene Polyester resins such as ethylene diformate; polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; not suitable for propylene polyurethane resins Polyurethane; Polyfluorene; Polyetheretherketone; Polyetherfluorene; Polyphenylene sulfide; Polyetherimide; Polyimide resins such as polyimide; Polyamine resin; Acrylic resin; Fluorine resin Wait.
The content ratio of the resin other than the propylene polyurethane resin and the olefin resin is preferably less than 30 parts by mass and more preferably 100 parts by mass of the total amount of the resin contained in the resin composition (y1). Less than 20 mass points, more desirably less than 10 mass points, still more desirably less than 5 mass points, and even more desirably less than 1 mass point.

It is preferred that the resin composition (y1) contains swellable particles.
The adhesive sheet (A) is an adhesive layer (X1) on which a processed object represented by a semiconductor wafer is placed when a swellable particle, not an adhesive layer, is contained on a substrate (Y1) having a high elastic modulus. ) Thickness adjustment, control of adhesion, viscoelasticity, etc., the freedom of design is improved. It is possible to suppress the positional deviation of the wafer obtained through this and the occurrence of wafer defects. Furthermore, in the case of using the adhesive sheet (A), since the wafer is placed on the adhesive surface of the adhesive layer (X1), the substrate (Y1) containing the expandable particles is not in direct contact with the wafer. As a result, a part of the adhesive layer that suppresses residues from the expandable particles and large deformation is attached to the wafer, and the uneven shape formed on the adhesive layer is transferred to the wafer to maintain cleanliness, and the wafer can be provided For the next project.
The optimum content of the expandable particles is as described above.

The resin composition (y1) is in a range in which the effect of the present invention is not impaired, and if necessary, an additive for a substrate may be contained.
Examples of the additives for the substrate include an ultraviolet absorber, a light stabilizer, an oxidation inhibitor, an antistatic agent, a slip agent, a release agent, and a colorant. Each of these base material additives may be used alone or in combination of two or more.
When these base material additives are contained, the content of each base material additive is preferably 0.0001 to 20 mass points, and more preferably 0.001 to 100 mass points of the resin in the resin composition (y1). 10 mass points.

[Solvent-free resin composition (y1 ')]
As one aspect of the resin composition (y1) used in this embodiment, an oligomer having an ethylenically unsaturated group having a mass average molecular weight (Mw) of 50,000 or less, and an energy ray polymerizable monomer may be mentioned. And a solvent-free resin composition (y1 ') prepared by blending the above-mentioned swellable particles without a solvent.
In the solventless resin composition (y1 '), although no solvent is prepared, the energy ray polymerizable monomer contributes to the constitution of improving the plasticity of the oligomer.
For a coating film formed from a solventless resin composition (y1 '), a substrate (Y1) can be obtained by irradiating an energy ray.
The types, shapes, and blending amounts (contents) of the swellable particles blended in the solventless resin composition (y1 ') are as described above.

The mass average molecular weight (Mw) of the aforementioned oligomer contained in the solventless resin composition (y1 ') is 50,000 or less, but is preferably 1,000 to 50,000, more preferably 2,000 to 40,000, and even more preferably 3,000 to 35,000. , And even more ideally 4000 ~ 30,000.

The oligomer is contained in the resin of the above-mentioned resin composition (y1) as long as it has an ethylenically unsaturated group having a mass average molecular weight (Mw) of 50,000 or less, but the above-mentioned urethane A prepolymer (UP) is preferred.
However, as the oligomer system, a denatured olefin resin having an ethylenically unsaturated group or the like may be used.

In the solventless resin composition (y1 '), the total content of the oligomer and the energy ray polymerization monomer is preferably the entire amount (100% by mass) of the solventless resin composition (y1'). It is 50 to 99% by mass, more preferably 60 to 95% by mass, more preferably 65 to 90% by mass, and even more preferably 70 to 85% by mass.

Examples of the energy ray polymerization single system include isofluorenyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentyl (meth) acrylate, and ethylene glycol di Alicyclic polymerizable compounds such as cyclopentenyl ether (meth) acrylate, cyclohexyl (meth) acrylate, adamantane (meth) acrylate, tricyclodecane acrylate; phenylhydroxypropyl Aromatic polymerizable compounds such as acrylate, benzyl acrylate, phenol ethylene oxide modified acrylate, etc .; ethylene oxide (meth) acrylate, morpholine acrylate, N-vinylpyrrolidone, N-vinyl A branchin cyclic polymerizable compound such as caprolactam.
These energy ray polymerization single systems can also be used alone or in combination of two or more.

In the solventless resin composition (y1 '), the content ratio of the oligomer and the energy ray polymerization monomer (the oligomer / energy ray polymerization monomer) is a mass ratio, and is preferably 20/80 ~ 90/10, more preferably 30/70 ~ 85/15, and even more preferably 35/65 ~ 80/20.

In this embodiment, it is preferable that the solventless resin composition (y1 ') is prepared by further blending a photopolymerization initiator.
Those who contain a photopolymerization initiator can sufficiently advance the curing reaction through irradiation with a relatively low energy energy ray.

Examples of the photopolymerization initiator include 1-hydroxycyclohexylphenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin cake ether, benzyl phenyl sulfide, Methylthiuram disulfide, azobisisobutyronitrile, dibenzyl, butanedione, 8-anthraquinone, etc.
Each of these photopolymerization initiators may be used alone or in combination of two or more.

The blending amount of the photopolymerization initiator is preferably 0.01 to 5 mass points, more preferably 0.01 to 4 mass points, and more preferably, the total amount (100 mass points) of the aforementioned oligomer and energy ray polymerization monomer. 0.02 ~ 3 mass points.

From the viewpoint of improving the adhesion between the base material (Y1) and the other layers that are laminated, the surface of the base material (Y1) is subjected to a surface treatment by an oxidation method, an unevenness method, or the like, and penetrates. Adjust processing, easy to follow processing. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet type), hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of the bump method include sandblasting. Treatment method, solvent treatment method, etc.

[Storage elasticity of base material (Y1)]
The storage elasticity E '(23) at 23 ° C of the base material (Y1) is preferably 1.0 × 10 ⁶ Pa or more, more preferably 5.0 × 10 ⁶ to 5.0 × 10 ¹² Pa, and still more preferably 1.0 × 10 ⁷ ~ 1.0 × 10 ¹² Pa, yet more preferably 5.0 × 10 ⁷ to 1.0 × 10 ¹¹ Pa, and still more preferably 1.0 × 10 ⁸ to 1.0 × 10 ¹⁰ Pa. When the storage elastic modulus E '(23) of the base material (Y1) is within the above-mentioned range, it is possible to suppress the occurrence of the positional deviation of the processed object during cutting and the positional deviation when transferring the wafer.
However, in this specification, the storage elasticity E 'of the base material (Y1) at a specific temperature means a value measured by the method described in Examples.

In the case where the base material (Y1) contains thermally expandable particles as expandable particles in the expandable base material (Y1-1), the expandable base material (Y1- 1) The storage elasticity E '(t) is preferably 1.0 × 10 ⁷ Pa or less. At the temperature at which the thermally expandable particles are expanded through this, the expandable substrate (Y1-1) easily deforms as the volume of the thermally expandable particles expands, and becomes an adhesion that easily forms unevenness on the adhesive layer (X1). surface. As a result, the person can be separated from the wafer by a small external force.
From the above viewpoint, the storage elastic modulus E '(t) of the expandable substrate (Y1-1) is more preferably 9.0 × 10 ⁶ Pa or less, still more preferably 8.0 × 10 ⁶ Pa or less, and still more preferably 6.0. × 10 ⁶ Pa or less, and more preferably 4.0 × 10 ⁶ Pa or less. In addition, from the viewpoint of suppressing the flow of the thermally expandable particles that expand, and improving the shape maintenance of the unevenness formed on the adhesive surface of the adhesive layer (X1), and further improving the separation, The storage elasticity E '(t) is preferably 1.0 × 10 ³ Pa or more, more preferably 1.0 × 10 ⁴ Pa or more, and still more preferably 1.0 × 10 ⁵ Pa or more.

(Non-swellable substrate (Y1 '))
The adhesive sheet (A) may have an adhesive layer (X1) on one surface of the substrate (Y1-1), and may have a non-swellable substrate (Y1 ') on the other surface.
The "non-expandable substrate" in the present specification is defined as a volume change rate calculated from the following formula when the expansion particles contained in the adhesive sheet (A) are expanded under a condition of less than 5% by volume. By.
Volume change rate (%) = (volume of the layer before processing-volume of the layer before processing) / volume of the layer before processing × 100
The volume change rate (%) of the non-expandable substrate (Y1 ') calculated from the above formula is preferably less than 2% by volume, more preferably less than 1% by volume, still more preferably less than 0.1% by volume, and more Ideally, it is less than 0.01% by volume.
The conditions under which the expandable particles expand are the cases where the expandable particles are thermally expandable particles, and the conditions under which a heat treatment is performed at the expansion start temperature (t) for 3 minutes.
The non-expandable base material (Y1 ') may contain expandable particles, but the smaller the content, the better, and the general mass (100% by mass) of the non-expandable base material (Y1') is usually , Less than 3% by mass, ideally less than 1% by mass, more desirably less than 0.1% by mass, still more desirably less than 0.01% by mass, and even more desirably less than 0.001% by mass, and those without swelling particles are the best .

Examples of the material forming the non-expandable substrate (Y1 ') include paper, resin, and metal.
Examples of the paper material include thin-leaf paper, medium-quality paper, high-quality paper, impregnated paper, coated paper, coated paper, sulfuric acid paper, and cellophane.
Examples of the resin system include polyolefin resins such as polyethylene and polypropylene; polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer. Ethylene resins; Polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc .; polystyrene; acrylonitrile-butadiene-styrene copolymerization Materials; cellulose triacetate; polycarbonate; urethane resins such as polyurethane, acrylic modified polyurethane; polymethylpentene; polyfluorene; polyetheretherketone; polyetherfluorene; Polyphenylene sulfide; polyetherimide; polyimide-based resins such as polyimide; polyimide-based resins; acrylic resins; fluorine-based resins.
Examples of the metal system include aluminum, tin, chromium, and titanium.
These forming materials may be constituted from one type, or two or more types may be used in combination.
Examples of the non-expandable base material (Y1 ') using two or more types of forming materials include a structure in which paper materials are laminated with a thermoplastic resin such as polyethylene, and formed on the surface of a resin film or sheet containing the resin. Structure of metal film, etc.
However, examples of the method for forming the metal layer include a method in which the above-mentioned metal is vapor-deposited by a PVD method such as vacuum deposition, sputtering, and ion plating, or a method in which the above-mentioned metal is attached using a general adhesive. Of metal foil.

In the case where the adhesive sheet (A) has a non-expandable substrate (Y1 '), before expanding the expansive particles, the thickness ratio of the expandable substrate (Y1-1) to the non-expandable substrate (Y1') [ The (Y1-1) / (Y1 ')] system is preferably 0.02 to 200, more preferably 0.03 to 150, and still more preferably 0.05 to 100.

From the viewpoint of improving the adhesion between the non-expandable substrate (Y1 ') and other layers that are laminated, the non-expandable substrate (Y1') contains a resin. For the non-expandable substrate (Y1 ') The surface of) is similar to the above-mentioned base material (Y1), and is subjected to a surface treatment by an oxidation method, an unevenness method, or the like, a permeation treatment, or an easy subsequent treatment.
When the non-swellable base material (Y1 ') contains a resin, it may be contained in the resin composition (y1) at the same time as the resin, and may contain the above-mentioned base material additive.

(Adhesive layer (X1))
The adhesive layer (X1) is an adhesive layer. The adhesive layer (X1) contains an adhesive resin, and may contain, as necessary, additives for adhesives such as a cross-linking agent, an adhesion-imparting agent, a polymerizable compound, and a polymerization initiator.

The adhesive force of the adhesive surface of the adhesive layer (X1) is at 23 ° C before the expansion of the expandable particles, and is preferably 0.1 to 10.0 N / 25 mm, more preferably 0.2 to 8.0 N / 25 mm, and more preferably 0.4 to 6.0. N / 25mm, and even more preferably 0.5 ~ 4.0N / 25mm. When the aforementioned adhesive force is 0.1N / 25mm or more, the workpiece can be sufficiently fixed, and the occurrence of the positional deviation of the workpiece during cutting can be suppressed. On the other hand, when the adhesive force is 10.0 N / 25 mm or less, it can be easily separated with only a slight force when it is separated from the wafer.
However, the above-mentioned adhesive force means a value measured by the method described in Examples.

The shear storage modulus G '(23) of the adhesive layer (X1) is at 23 ° C, preferably 1.0 × 10 ⁴ to 1.0 × 10 ⁸ Pa, more preferably 5.0 × 10 ⁴ to 5.0 × 10 ⁷ Pa, Still more preferably, it is 1.0 × 10 ⁵ to 1.0 × 10 ⁷ Pa. When the shear force storage modulus G '(23) of the adhesive layer (X1) is 1.0 × 10 ⁴ Pa or more, it is possible to prevent the position of the wafer from being shifted when the wafer is separated from the wafer. On the other hand, when the shear storage modulus G '(23) of the adhesive layer (X1) is 1.0 × 10 ⁸ Pa or less, the unevenness of the swollen expandable particles is easily formed on the adhesive surface, which can be slightly increased. The force is easily carried by the detacher.
The adhesive sheet (A) is a case of an adhesive sheet having a plurality of adhesive layers. The shear storage modulus G '(23) of the adhesive layer attached to the wafer is preferably within the above range, which is better than the substrate (Y1). ) The shear storage modulus G '(23) of all the adhesive layers on the wafer side is preferably within the above range.
However, in this specification, the shear storage modulus G '(23) of the adhesive layer (X1) means the value measured by the method described in an Example.

The thickness of the adhesive layer (X1) is from the viewpoint of finding superior adhesion and the expansion of the swellable particles in the swellable substrate through heat treatment to easily form irregularities on the surface of the formed adhesive layer. It is preferably 1 to 60 μm, more preferably 2 to 50 μm, still more preferably 3 to 40 μm, and still more preferably 5 to 30 μm.

The ratio of the thickness of the substrate (Y1) to the thickness of the adhesive layer (X1) (substrate (Y1) / adhesive layer (X1)) is from the viewpoint of preventing the positional shift of the wafer at 23 ° C. It is preferably 0.2 or more, more preferably 0.5 or more, still more preferably 1.0 or more, and more preferably 5.0 or more. In addition, when performing separation, the adhesiveness can be easily separated with only a small force. The viewpoint of the sheet is preferably 1,000 or less, more preferably 200 or less, still more preferably 60 or less, and still more preferably 30 or less.
The thickness of the adhesive layer (X1) means a value measured by the method described in Examples.

The adhesive layer (X1) can be formed from an adhesive composition (x1) containing an adhesive resin. Hereinafter, each component which can be contained in an adhesive composition (x1) is demonstrated.

[Adhesive resin]
The adhesive resin of the material for forming the adhesive layer (X1) is a polymer having a single adhesive property and a polymer having a mass average molecular weight (Mw) of 10,000 or more. The mass average molecular weight (Mw) of the adhesive resin is from the viewpoint of improving the adhesive force, and is more preferably 10,000 to 2 million, more preferably 20,000 to 1.5 million, and even more preferably 30,000 to 1 million.

Examples of the adhesive resins include rubber resins such as acrylic resins, urethane resins, and polyisobutylene resins, polyester resins, olefin resins, silicone resins, and polyvinyl ethers. Department of resin and so on.
These adhesive resins may be used alone or in combination of two or more.
In addition, when these adhesive resins are copolymers having two or more constituent units, the morphology of the copolymers is not particularly limited, and may be block copolymers, random copolymers, and graft copolymerization. Anything.

The adhesive resin may be an energy ray-curable adhesive resin having a polymerizable functional group based on a side chain of the adhesive resin.
Examples of the polymerizable functional group include (meth) acrylfluorenyl, vinyl, and the like.
Examples of the energy ray system include ultraviolet rays and electron rays, but ultraviolet rays are preferred.

The content of the adhesive resin is preferably 30 to 99.99% by mass, more preferably 40 to 99.95% by mass, and even more preferably 50 to the total amount (100% by mass) of the active ingredient of the adhesive composition (x1). It is ~ 99.90 mass%, more preferably 55 ~ 99.80 mass%, and still more preferably 60 ~ 99.50 mass%.
However, in the following descriptions of this specification, "the content of each component with respect to the total amount of the active ingredients of the adhesive composition" means "each component in the adhesive layer formed from the adhesive composition." Content "is synonymous.

The adhesive resin is an adhesive resin sheet containing acrylic resin from the standpoint that it is easy to form an adhesive sheet that is improved in the adhesion surface through expansion bumps of the expandable particles at the same time as the superior adhesion is found. good.
The content ratio of the acrylic resin in the adhesive resin is preferably 30 to 100% by mass, and more preferably 50 to the total amount (100% by mass) of the adhesive resin contained in the adhesive composition (x1). It is 100% by mass, more preferably 70-100% by mass, and still more preferably 85-100% by mass.

[Acrylic resin]
It can be used as an adhesive resin, and examples of the acrylic resin include a polymer containing a constituent unit derived from an alkyl (meth) acrylate having a linear or branched alkyl group, and a polymer derived from having a ring (Meth) acrylic acid ester-like structural unit of polymer, etc., and has a constitutional unit derived from alkyl (meth) acrylate (a1 ') (hereinafter, also referred to as "monomer (a1')") (a1) and the acrylic copolymer (A1) derived from the structural unit (a2) of the functional group-containing monomer (a2 ') (hereinafter, also referred to as "monomer (a2')").

The carbon number of the alkyl group contained in the monomer (a1 ') is preferably from 1 to 24, more preferably from 1 to 12, more preferably from 2 to 10, and even more preferably from 4 from the viewpoint of improvement in adhesion characteristics. ~ 8.
However, the alkyl group which the monomer (a1 ') has may be a straight-chain alkyl group, and may be a branched-chain alkyl group.
Examples of the monomer (a1 ') include meth (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, etc.
These monomers (a1 ') may be used alone or in combination of two or more.
The monomer (a1 ') is preferably a butyl (meth) acrylate and a 2-ethylhexyl (meth) acrylate.
The content of the constitutional unit (a1) is preferably 50 to 99.9 mass%, more preferably 60 to 99.0 mass%, and more preferably to the entire constitutional unit (100 mass%) of the acrylic copolymer (A1). It is 70 to 97.0% by mass, and even more preferably 80 to 95.0% by mass.

As a functional group system which a monomer (a2 ') has, a hydroxyl group, a carboxyl group, an amino group, an epoxy group, etc. are mentioned, for example.
That is, examples of the monomer (a2 ') include a hydroxyl group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, and an epoxy group-containing monomer.
These monomers (a2 ') may be used alone or in combination of two or more.
Among these, the monomer (a2 ') is preferably a hydroxyl group-containing monomer and a carboxyl group-containing monomer.
Examples of the hydroxyl group-containing single system include the same structure as the above-mentioned hydroxyl group-containing compound.
Examples of the carboxyl-containing monosystem include ethylenically unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid, and citraconic acid. Carboxylic acid and its anhydride, ethyl 2- (propenyloxy) succinate, 2-carboxyethyl (meth) acrylate and the like.
The content of the constituent unit (a2) is preferably from 0.1 to 40 mass%, more preferably from 0.5 to 35 mass%, and more preferably for the total constituent unit (100 mass%) of the acrylic copolymer (A1). It is 1.0 to 30% by mass, and more preferably 3.0 to 25% by mass.

The acrylic copolymer (A1) may further have a constituent unit (a3) derived from a monomer (a3 ') other than the monomers (a1') and (a2 ').
However, in the acrylic copolymer (A1), the content of the constituent units (a1) and (a2) is preferably 70 to 100 for the entire constituent unit (100% by mass) of the acrylic copolymer (A1). It is more preferably 80% to 100% by mass, more preferably 90 to 100% by mass, and even more preferably 95 to 100% by mass.

Examples of the monomer (a3 ') include: olefins such as ethylene, propylene, and isobutene; halogenated olefins such as vinyl chloride and vinylidene chloride; butadiene, isoprene, and isoprene And other diene monomers; with cyclohexyl (meth) acrylate, diphenylenedione (meth) acrylate, isofluorenyl (meth) acrylate, dicyclopentyl (meth) acrylate (Meth) acrylates with cyclic structures such as esters, dicyclopentene (meth) acrylates, ethylene glycol dicyclopentenyl ether (meth) acrylates, amidine (meth) acrylates, etc. ; Styrene, α-methylstyrene, vinyltoluene, ethylene formate, vinylacetic acid, acrylonitrile, (meth) acrylamide, (meth) acrylonitrile, (meth) acrylic morpholine, N- Vinyl pyrrolidone and the like.

The acrylic copolymer (A1) may be an energy ray-curable acrylic copolymer having a polymerizable functional group based on a side chain. The polymerizable functional group and the energy ray system are as described above. However, the polymerizable functional group is an acrylic copolymer having the above-mentioned constituent units (a1) and (a2), and a substitution group having a functional group that can be bonded to the acrylic unit-containing constituent unit (a2). Those who react with a polymerizable functional group compound may be introduced.
Examples of the compound system include isocyanoethyl (meth) acrylate, (meth) acrylic acid isocyanate, and epoxypropyl (meth) acrylate.

The mass average molecular weight (Mw) of the acrylic resin is preferably 100,000 to 1.5 million, more preferably 200,000 to 1.3 million, still more preferably 350,000 to 1.2 million, and even more preferably 500,000 to 1.1 million.

[Crosslinking agent]
In the case where the adhesive composition (x1) is an adhesive resin containing a functional group of the acrylic copolymer (A1) as described above, it is more preferable that it contains a crosslinking agent.
This crosslinking agent reacts with an adhesive resin having a functional group, uses the functional group as a starting point for crosslinking, and crosslinks the adhesive resins to each other.
Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, and metal chelate-based crosslinking agents.
These crosslinking agents may be used alone or in combination of two or more.
Among these cross-linking agents, an isocyanate-based cross-linking agent is preferred from the viewpoint of increasing the cohesive force and increasing the adhesive force, and from the viewpoint of being easy to obtain.
The content of the cross-linking agent is appropriately adjusted by the number of functional groups of the adhesive resin. However, for 100 mass parts of the adhesive resin having a functional group, it is preferably 0.01 to 10 mass parts, and more preferably It is 0.03 to 7 mass points, and more preferably 0.05 to 5 mass points.

[Adhesion imparting agent]
The adhesive composition (x1) may contain an adhesion-imparting agent from the viewpoint of further improving the adhesion.
In this specification, "adhesion imparting agent" refers to a component that supplementally improves the adhesion of the above-mentioned adhesive resin, and the mass average molecular weight (Mw) means an oligomer of less than 10,000 and the above-mentioned adhesive resin Make a difference.
The mass average molecular weight (Mw) of the adhesion-imparting agent is preferably 400 to 10,000, more preferably 500 to 8000, and still more preferably 800 to 5000.

Examples of the adhesion-imparting agent system include turpentine resin, terpene resin, styrene resin, copolymerization of pentene produced by thermal decomposition of naphtha, isoprene, piperine, 1,3 -C5 based petroleum resins obtained from the C5 fraction of cyclopentadiene, etc., copolymerized with indene produced by thermal decomposition of naphtha, C9 based petroleum resins obtained from the C9 fraction of vinyl toluene, etc., and hydrogenated Of hydrogenated resin.

The softening point of the adhesion imparting agent is preferably 60 to 170 ° C, more preferably 65 to 160 ° C, and still more preferably 70 to 150 ° C.
However, in this specification, the "softening point" of an adhesion imparting agent means the value measured based on JISK2531.
The adhesion-imparting agent may be used alone, or two or more different ones having different softening points and structures may be used in combination. In the case where two or more types of adhesion imparting agents are used, it is preferable that the softening point of the plurality of adhesion imparting agents increase in average within the above range.

The content of the adhesion-imparting agent is preferably from 0.01 to 65% by mass, more preferably from 0.05 to 55% by mass, and more preferably from 0.1 to the entire amount (100% by mass) of the active ingredient of the adhesive composition (x1). It is ~ 50% by mass, more preferably 0.5 ~ 45% by mass, and even more preferably 1.0 ~ 40% by mass.

[Photopolymerization initiator]
In the present embodiment, when the adhesive composition (x1) contains an energy ray-curable adhesive resin as an adhesive resin, it is more preferable to include a photopolymerization initiator.
The adhesive composition containing an energy-ray-curable adhesive resin and a photopolymerization initiator can sufficiently advance the curing reaction through irradiation with a relatively low-energy energy beam, and can adjust the adhesive force to a desired value. Range of people.
However, examples of the photopolymerization initiator include those having the same composition as the solvent-free resin composition (y1).
The content of the photopolymerization initiator is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and still more preferably 0.05 to 2 parts by mass for 100 parts by mass of the energy-ray-curable adhesive resin.

[Additives for adhesives]
In this embodiment, the adhesive composition (x1) of the material for forming the adhesive layer (X1) is in a range that does not impair the effects of the present invention. In addition to the additives described above, the adhesive contains adhesives used in general adhesives. Additives may also be used.
Examples of such additives for adhesives include oxidation inhibitors, softeners (plasticizers), rust inhibitors, pigments, dyes, retarders, reaction accelerators (catalysts), and ultraviolet absorbers.
However, each of these adhesive additives may be used alone or in combination of two or more.
When these adhesive additives are contained, the content of each of the adhesive additives is preferably 0.0001 to 20 mass points, more preferably 0.001 to 10 mass points for 100 mass points of the adhesive resin.
The adhesive layer (X1) may contain swellable particles. The content thereof is preferably 5 parts by mass or less for 100 parts by mass of the adhesive resin, more preferably 2 parts by mass or less, and it is most preferable if it is not contained.

(Peeling material)
Examples of the release material to be used include a structure in which a release agent is used as a double-sided release treatment, a release sheet is used as a single-sided release treatment, and a release agent is applied to a substrate for the release material.
Examples of the base material for the release material include papers such as high-quality paper, cellophane, and kraft paper; polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate Polyester resin films such as diester resins, polypropylene resins, polyolefin resin films of polyethylene resins, and other plastic films; etc.
Examples of the release agent include rubber-based elastomers such as silicone resins, polyolefin resins, isoprene resins, and butadiene resins, long-chain alkyl resins, and alkyd resins. Resin, fluororesin, etc.
The thickness of the release material is not particularly limited, but is preferably 10 to 200 μm, more preferably 25 to 170 μm, and still more preferably 35 to 80 μm.

<Manufacturing method of the adhesive sheet (A)>
The manufacturing method of the adhesive sheet (A) is not specifically limited, For example, the manufacturing method (I) which has the following processes (Ia) and (Ib) is mentioned.
Process (Ia): coating the resin composition (y1) of the forming material of the base material (Y1) on the release-treated surface of the release material to form a coating film, and drying or UV curing the coating film to form the base material (Y1) Of works.
Process (Ib): coating the adhesive composition (x1) of the forming material of the adhesive layer (X1) on the surface of the formed substrate (Y1) to form a coating film, and drying the coating film to form an adhesive Construction of layer (X1).

As another manufacturing method of an adhesive sheet (A), the manufacturing method (II) which has the following processes (IIa)-(IIc) is mentioned, for example.
Process (IIa): coating the resin composition (y1) of the forming material of the substrate (Y1) on the release-treated surface of the release material to form a coating film, and drying or UV curing the coating film to form the substrate (Y1) Of works.
Process (IIb): A process of coating an adhesive composition (x1) of a forming material of an adhesive layer (X1) on a release-treated surface of a release material to form a coating film, and drying the coating film to form an adhesive layer.
Process (IIc): a process for attaching to the surface of the substrate (Y1) formed in the process (IIa) and the surface of the adhesive layer (X1) formed in the process (IIb).

In the above-mentioned production methods (I) and (II), the resin composition (y1) and the adhesive composition (x1) are prepared by diluting a solvent and may be in the form of a solution.
Examples of the coating method include a spin coating method, a spray coating method, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, and a gravure coating method.

However, it is preferable that the drying method or the UV irradiation method of the manufacturing method (I) and the manufacturing method (II) is performed by appropriately selecting conditions in which the expandable particles are not expanded. For example, when the resin composition (y1) containing the thermally expandable particles is dried to form the substrate (Y1), the drying temperature is preferably performed at a temperature lower than the expansion start temperature (t) of the thermally expandable particles.
In addition, when the adhesive sheet (A) has an expandable substrate (Y1-1) and a non-expandable substrate (Y1 '), the resin composition (y1) is in the aforementioned processes (Ia) and (IIa). For example, it may be applied in advance on the formed non-expandable substrate (Y1 '). The non-expandable base material (Y ') is, for example, a resin composition that can be formed using a material for forming the non-expandable base material (Y') and is formed in the same manner as in the aforementioned processes (Ia) and (IIa).

[Method for Manufacturing Semiconductor Device According to the Embodiment]
Next, each process of the method for manufacturing a semiconductor device according to this embodiment will be described.
The method for manufacturing a semiconductor device according to this embodiment has the following procedures (1) to (3).
Process (1): After attaching the processed object to the adhesive layer (X1) of the adhesive sheet (A), cutting the processed object to obtain a plurality of wafers that are sliced on the adhesive layer (X1) .
Process (2): using an adhesive sheet (B) having a base material (Y2) and an adhesive layer (X2), attaching the adhesive on the side opposite to the surface to which the adhesive layer (X1) of the plurality of wafers is bonded Process of adhesive layer (X2) of sheet (B).
Process (3): A process of expanding the expandable particles and separating the plurality of wafers and the adhesive sheet (A) attached to the adhesive sheet (B).
Hereinafter, an example in which a semiconductor wafer is used as a workpiece will be described with reference to the drawings.

＜ Engineering (1) ＞
For (a) and (b) of FIG. 2, it is shown that the semiconductor wafer W is attached to the adhesive layer (X1) of the adhesive sheet (A), and then the semiconductor wafer W is cut to obtain a wafer (X1). (1) A cross-sectional view of the process (1) of a plurality of semiconductor wafers CP.

The semiconductor wafer W is, for example, a silicon wafer or a compound semiconductor wafer such as gallium and arsenic.
The semiconductor wafer W has a circuit W2 on its circuit surface W1. Examples of the method for forming the circuit W2 include an etching method and a lift-off method. However, in this specification, a surface on the opposite side to the circuit surface W1 is referred to as a "chip back surface".
The semiconductor wafer W is ground to a predetermined thickness so that the back surface of the wafer is exposed and adhered to the adhesive sheet (A). Examples of a method for grinding the semiconductor wafer W include a known method using a grinder or the like.
For the purpose of holding the semiconductor wafer W for the adhesive sheet (A), a ring frame may be attached. In this case, a ring frame and a semiconductor wafer W are placed on the adhesive layer (X1) of the adhesive sheet (A), and they are fixed by gently pressing them.
Next, the semiconductor wafer W held on the adhesive sheet (A) is diced to form individual pieces, and a plurality of semiconductor wafers CP are formed. For the cutting system, for example, cutting means such as a cutter, laser, plasma cutting, stealth cutting, etc. are used. The cutting depth at the time of dicing may be appropriately set in consideration of the thickness of the semiconductor wafer, but may be, for example, a depth within 2 μm on the self-adhesive layer (X1).
However, in order to distinguish this process from another cutting process described later, it may be referred to as a "first cutting process".
In the process (1), after the semiconductor wafer W is diced, in order to expand the space between the plurality of semiconductor wafers CP obtained, a process including stretching the adhesive sheet (A) may be used.

＜ Engineering (2) ＞
FIG. 3 shows the use of an adhesive sheet (B) having a substrate (Y2) and an adhesive layer (X2) on the side opposite to the surface bonded to the adhesive layer (X1) of a plurality of semiconductor wafers CP. A cross-sectional view of the process (2) with the adhesive layer (X2) of the adhesive sheet (B).

The form of the adhesive sheet (B) may be appropriately determined in accordance with the subsequent process. For example, as the next process of the first dicing process, when the expansion process of expanding the interval of a plurality of semiconductor wafers CP is performed, as the adhesive sheet (B), for example, an adhesive sheet for expansion (hereinafter, also referred to as " Expansion tape "). On the other hand, in consideration of the workability of subsequent processes, a reversal process is performed between the first cutting process and the expansion process to reverse the front and back surfaces of the plurality of semiconductor wafers CP (that is, the circuit surface W1 and the back surface of the wafer). In this case, it is sufficient to use an adhesive sheet for inversion (hereinafter also referred to as "adhesive sheet for inversion").
FIG. 3 shows an example in which an adhesive sheet for inversion is used as the adhesive sheet (B).
Next, the best form of the adhesive sheet (B) will be described as an inversion adhesive sheet and an expansion tape.

(Adhesive sheet for reverse)
The reversing adhesive sheet has a substrate (Y2) and an adhesive layer (X2). After transferring a plurality of semiconductor wafers CP from the adhesive sheet (A), the plurality of semiconductor wafers CP are further transferred to another The adhesive sheet is used in order to invert the surface in contact with the adhesive layer of the semiconductor wafer CP.
The inversion adhesive sheet is not particularly limited as long as it can achieve the above purpose, but it must be capable of being attached to and separated from a semiconductor wafer, such as an adhesive sheet containing expandable particles such as the adhesive sheet (A), and an expansion tape described later An adhesive sheet having an adhesive layer composed of a non-energy ray-curable adhesive having self-releasing properties, and an adhesive sheet having an adhesive layer composed of a self-energy ray-curable adhesive are preferable.
The base material (Y2) of the adhesive sheet for reversal is formed using the structure mentioned as the formation material of the base material (Y1) of the adhesive sheet (A). Moreover, the adhesive layer (X2) as an inversion adhesive sheet can be formed using the structure mentioned as the formation material of the adhesive layer (X1) or the adhesive layer (X2) of the expansion tape mentioned later.
When the adhesive sheet (A) is used as the adhesive sheet (B), the form of the adhesive sheet (A) used in the process (1) and the form of the adhesive sheet (A) used in the process may be the same. Or different.

The thickness of the substrate (Y2) of the reversing adhesive sheet is preferably 10 to 1000 μm, more preferably 20 to 500 μm, still more preferably 25 to 400 μm, and still more preferably 30 to 300 μm.
The thickness of the adhesive layer (X2) of the reversing adhesive sheet is preferably 1 to 60 μm, more preferably 2 to 50 μm, still more preferably 3 to 40 μm, and still more preferably 5 to 30 μm.

(Expansion tape)
Next, as an expansion tape, the optimal adhesive sheet (B) is demonstrated.
The expansion tape has a substrate (Y2) and an adhesive layer (X2), and a plurality of semiconductor wafers CP are transferred from the adhesive sheet (A) to the adhesive layer (X2) in order to space the plurality of semiconductor wafers CP between The stretched adhesive sheet (B) is expanded and used.

Examples of the material of the base material (Y2) of the expansion tape include polyvinyl chloride resin, polyester resin (polyethylene terephthalate, etc.), acrylic resin, polycarbonate resin, polyethylene resin, and polyethylene. Acrylic resin, acrylonitrile, butadiene, styrene resin, polyimide resin, polyurethane resin, and polystyrene resin.
The base material (Y2) of the expansion tape is preferably a thermoplastic elastomer, a rubber-based material, etc., and a thermoplastic elastomer is more preferred.
Examples of the thermoplastic elastic system include urethane-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, styrene-based elastomers, acrylic-based elastomers, and fluorene-based elastomers. Wait.

The base material (Y2) of the expansion tape may be a film formed by laminating the above materials in a plurality of layers, and a film formed by laminating the above materials and other films may also be used.
The base material (Y2) of the expansion tape is contained in the film using the above-mentioned resin-based material as the main material, and contains various additives such as pigments, dyes, flame retardants, plasticizers, antistatic agents, slip agents, fillers, etc .

The adhesive layer (X2) of the expansion tape may be composed of a non-energy-ray-curable adhesive, or may be composed of an energy-ray-curable adhesive.
The non-energy ray hardening adhesive is preferably a composition having desired adhesion and re-peelability. Examples include acrylic adhesives, rubber adhesives, silicone adhesives, and urethane. Ester-based adhesives, polyester-based adhesives, polyvinyl ether-based adhesives, and the like. Among these, an acrylic pressure-sensitive adhesive is preferred from the viewpoint of effectively suppressing peeling of a semiconductor wafer or the like when the adhesive sheet (B) is stretched.

The energy ray-curable adhesive is hardened by energy ray irradiation, and the adhesive force is reduced. When the semiconductor wafer is separated from the adhesive sheet (B), it can be easily separated by energy ray irradiation.
Examples of the energy ray-curable adhesive system constituting the adhesive layer (X2) of the expansion tape include those selected from (a) a polymer having energy ray curability, and (b) having at least one type of polymer. One or more types of monomers and / or oligomers of the energy ray-curable group.
(a) As a polymer having energy ray hardening property, a (meth) acrylate (co) polymer having an energy ray hardening functional group (energy ray hardening group) having an unsaturated group and the like in the side chain is introduced. Better. Examples of the acrylate (co) polymer system include an alkyl (meth) acrylate having 1 to 18 carbon atoms, a polymerizable double bond, and a hydroxyl group and a carboxylic acid. The functionalities of amino, substituted amino, and epoxy are based on the copolymerization of monomers in the molecule, and the structure obtained by reacting an unsaturated group-containing compound having a functional group bonded to the functional group.
(b) Examples of monomers and / or oligomers having at least one energy ray-curable group include esters of a polyvalent alcohol and acrylic acid, and specifically, cyclohexyl (methyl ) Acrylic esters, isofluorenyl (meth) acrylates, etc. monofunctional acrylates, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (methyl) ) Acrylic ester, polydipentaerythritol hexa (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di Polyfunctional acrylates such as (meth) acrylates, tricyclodecanedimethanol di (meth) acrylates, polyester oligo (meth) acrylates, polyurethane oligo (meth) acrylates, etc. .
In the energy ray-curable adhesive, in addition to the above components, a photopolymerization initiator, a cross-linking agent, and the like may be appropriately blended.

The thickness of the base material (Y2) of the expansion tape is not particularly limited, but it is preferably 20 to 250 μm, and more preferably 40 to 200 μm.
The thickness of the adhesive layer (X2) of the expansion tape is not particularly limited, but is preferably 3 to 50 μm, and more preferably 5 to 40 μm.

At 23 ° C., the elongation at break of the expansion tape measured in the MD direction and the CD direction is preferably 100% or more each. When the elongation at break is in the above range, the elongation can be increased. Therefore, for the manufacture of a fan-out package, it is necessary to sufficiently separate semiconductor wafers from each other, and it can be used appropriately.

However, the adhesive layer (X2) of the adhesive sheet (B) is composed of an energy ray-curable adhesive. It is preferable that the expandable particles of the adhesive sheet (A) are thermally expandable particles.

＜ Engineering (3) ＞
FIG. 4 is a cross-sectional view illustrating a process (3) of expanding the aforementioned thermally expandable particles and separating a plurality of semiconductor wafers CP and an adhesive sheet (A).
In this process, when the expandable particles are expanded by heat, energy rays, etc. according to their type, they form unevenness on the adhesive surface (X1a) of the adhesive layer (X1), and then pass through this to make the adhesive surface (X1a) ) The adhesive force with a plurality of semiconductor wafers CP is reduced, and the adhesive sheet (A) is separated from the plurality of semiconductor wafers CP.

The method of expanding the expandable particles may be appropriately selected according to the type of the expandable particles, and when the expandable particles are thermally expandable particles, heating may be performed at a temperature equal to or higher than the expansion start temperature (t). Here, as the "temperature above the expansion start temperature (t)", it is preferable that it is "the expansion start temperature (t) + 10 ° C" or more and "the expansion start temperature (t) + 60 ° C" or less, and "the expansion start temperature (t) + 15 ° C "or more" Expansion start temperature (t) + 40 ° C "or less is more preferred. Specifically, depending on the type of the expandable particles, for example, it may be expanded by heating in the range of 70 to 330 ° C.

The expansion of the expandable particles is preferably performed in a state where the surface (Y1a) on the side opposite to the adhesive layer (X1) of the base material (Y1) is fixed. When passing through the fixed surface (Y1a), the occurrence of unevenness on the side of the surface (Y1a) is physically suppressed, and the unevenness on the adhesive surface (X1a) side of the adhesive layer (X1) can be efficiently formed. The fixation system may adopt any method, and examples thereof include a method in which the non-expandable base material (Y1 ') is provided on the surface (Y1a) side of the base material (Y1), and is used as a fixing jig. A method for fixing a suction table of a plurality of suction holes to a surface (Y1a) of a base material (Y1), and attaching a hard support to a surface (Y1a) of the base material (Y1) by using an arbitrary adhesive layer, a sheet on both sides, and the like. ).
The suction table has a pressure reducing mechanism such as a vacuum pump, and a plurality of suction holes are provided through the pressure reducing mechanism to fix the target to the suction surface when the target is attracted.
The material of the hard support may be appropriately determined in consideration of mechanical strength and heat resistance. For example, metal materials such as SUS; non-metal inorganic materials such as glass and silicon wafers; epoxy, ABS, acrylic, engineering plastics, super engineering plastics, polyimide, polyimide and other resin materials; glass epoxy resin and other composite materials, among these, SUS, glass, and silicon wafers And so on. Examples of the engineering plastics include nylon, polycarbonate (PC), and polyethylene terephthalate (PET). Examples of the super engineering plastics include polyphenylene sulfide (PPS), polyether fluorene (PES), and polydiether ketone (PEEK).

＜ Expansion Project ＞
Next, an expansion process is performed to expand the interval between the plurality of semiconductor wafers CP obtained as described above.
The expansion process is based on the form of the adhesive sheet (B). After the process (3), the following process (4A) or processes (4B-1) to (4B-3) (hereinafter also referred to as "process (4B) ) ").

Process (4A): The adhesive sheet (B) is an adhesive sheet for expansion, and is a process of stretching and expanding the aforementioned adhesive sheet for expansion between the plurality of semiconductor wafers attached to the adhesive sheet (B).

Process (4B-1): On the side opposite to the surface bonded to the adhesive layer (X2) of the plurality of semiconductor wafers on the adhesive sheet (B), attach the adhesive layer (C) of the adhesive sheet (C) of the expansion tape ( X3) works.
Process (4B-2): A process of separating the adhesive sheet (B) from a plurality of semiconductor wafers CP attached to the adhesive sheet (C).
Process (4B-3): A process of stretching and expanding the aforementioned adhesive sheet for expansion between the plurality of semiconductor wafers attached to the adhesive sheet (C).

The process (4A) refers to the case where the adhesive sheet (B) used in the process (2) is an expansion tape. In this case, the interval between the plurality of semiconductor wafers CP may be expanded by stretching the adhesive sheet (B).

The process (4B) system adhesive sheet (B) is the case of reversing adhesive sheet, self-reversing adhesive sheet (B), transfer of a plurality of semiconductor wafers CP to expansion adhesive sheet ( C) After that, the expansion project is carried out.
In this embodiment, the process (4B) will be described.

5 (a) and 5 (b) show the surface on the opposite side to the surface which is in contact with the adhesive layer (X2) of the plurality of semiconductor wafers CP on the adhesive sheet (B) for inversion. Section (4B-1) of the process (4B-1) of the adhesive layer (X3) of the adhesive sheet (C) with an expansion tape, and then a process (4B-2) of separating the adhesive sheet (B) from the plurality of semiconductor wafers CP.
The method for separating the adhesive sheet (B) from the plurality of semiconductor wafers CP is appropriately selected according to the type of the adhesive sheet (B), and the adhesive layer (X2) of the adhesive sheet (B) is hardened from non-energy rays. In the case of an adhesive, it is only necessary to peel it off under specific conditions. The adhesive layer (X2) is made of an energy ray-curable adhesive. It is cured by energy ray irradiation to make the adhesive. Separation can be performed after the force is reduced.
The ideal form of the expansion tape is as described above.

Figures 6 (a) and (b) show the process of stretching and expanding the adhesive sheet (C) between the plurality of semiconductor wafers attached to the adhesive sheet (C) for expansion tape (4B-3). Section view.
After the above process, as shown in FIG. 6 (a), a plurality of semiconductor wafers CP are placed on the adhesive layer (X3) of the adhesive sheet (C).
Next, as shown in FIG. 6 (b), the adhesive sheet (C) is stretched to extend the distance between the plurality of semiconductor wafers CP to a distance D.
Examples of the method of stretching the adhesive sheet (C) include a method of stretching the adhesive sheet (C) by pushing against a ring-shaped or circular dilator, and grasping the outer periphery of the adhesive sheet (C) using a holding member or the like. And stretching methods.
The distance D between the plurality of expanded semiconductor wafers CP may be appropriately determined depending on the desired form of the semiconductor device, but is preferably 50 to 6000 μm.

＜ Engineering (5) ~ (8) ＞
The method for manufacturing a semiconductor device according to this embodiment uses an adhesive sheet (D) having a base material (Y4) and an adhesive layer (X4), and the following processes (5) to (8) may be performed.
Process (5): A process of transferring a plurality of semiconductor wafers CP whose intervals are expanded by an expansion process to an adhesive layer (X4) of an adhesive sheet (D).
Process (6): Covering the plurality of semiconductor wafers CP with a sealing material and the peripheral portion of the plurality of semiconductor wafers CP among the adhesive surfaces of the adhesive layer (X4), curing the sealing material to obtain the semiconductor wafer The process of sealing in a hardened closed body made of hardened sealing material.
Process (7): a process for separating the adhesive sheet (D) from the aforementioned hardened closed body.
Process (8): The process of separating the hardened closed body of the adhesive sheet (D) to form a redistribution layer.
However, as the adhesive sheet (D), it is also possible to use the adhesive sheet (C) of an expansion tape, and in this case, it is not necessary to perform the process (5). In this case, the adhesive sheet (D) described below has a structure that means the adhesive sheet (C).
Hereinafter, the processes (5) to (8) will be described in order.

[Engineering (5)]
Process (5): A process of transferring a plurality of semiconductor wafers CP whose intervals are expanded by an expansion process to an adhesive layer (X4) of an adhesive sheet (D).
7 (a) and 7 (b) show the surface of the adhesive sheet (D) opposite to the surface in contact with the adhesive layer (X3) of the plurality of semiconductor wafers CP on the expansion adhesive sheet (C). A cross-sectional view of the process of separating the adhesive sheet (C) from the plurality of semiconductor wafers CP after the adhesive layer (X4).
Here, the adhesive sheet (D) has a structure in which a plurality of semiconductor wafers CP are closed on the adhesive surface (X4a) to obtain a hardened closed body, and the hardened closed body is separated from the hardened closed body. Accordingly, for the adhesive sheet (D) to be enclosed between the closed bodies, there is no positional deviation of the semiconductor wafer, and it is required that the sealing material does not enter the extent of the bonding interface between the semiconductor wafer and the temporarily fixed sheet. Adhesiveness and separability that can be easily removed after sealing.
The adhesive sheet (D) is not particularly limited as long as it can achieve the above purpose, but it must be capable of being attached to and separated from a semiconductor wafer. For example, an adhesive sheet containing expandable particles such as the adhesive sheet (A) has a self-owned An adhesive sheet having an adhesive layer composed of a peelable non-energy ray-curable adhesive, and an adhesive sheet having an adhesive layer composed of an energy ray-curable adhesive are most preferable. Among these, it is preferable to use an adhesive sheet (A) especially from the viewpoint of coexistence of superior adhesiveness and separability.
When the adhesive sheet (A) is used as the adhesive sheet (D), the form of the adhesive sheet (A) used in the process (1) and the form of the adhesive sheet (A) used in the process may be the same. Or different.

In this process, the method of separating the adhesive sheet (C) and the plurality of semiconductor wafers CP is the same as in the case of the adhesive sheet (B), and it may be determined according to the form of the adhesive sheet (C).

[Engineering (6)]
FIGS. 8 (a) to 8 (c) show the peripheral portion 45 of the plurality of semiconductor wafers CP covered with the sealing material 40 and the adhesive surface (X4a) of the adhesive layer (X4). (Hereinafter, this process is also referred to as "covering process"), the sealing material 40 is hardened (hereinafter, this process is also referred to as "hardening process"), and a plurality of closed semiconductor wafers CP are obtained on the hardened sealing material 41. Sectional view of process (6) of the resulting hardened closed body 50.

The sealing material 40 is a person having a plurality of semiconductor wafers CP from external environmental protection and a function accompanying the elements. The sealing material 40 is not particularly limited, and it is possible to appropriately select an arbitrary structure from among conventional structures used as a semiconductor sealing material for the user.
The sealing material 40 has a hardenable structure from the viewpoints of mechanical strength, heat resistance, insulation, and the like, and examples thereof include a thermosetting resin composition, an energy ray hardening resin composition, and the like.
Examples of the thermosetting resin system of the thermosetting resin composition containing the sealing material 40 include epoxy resin, phenol resin, cyanate resin, and the like. From the standpoint of sex, epoxy resin is preferred.
The said thermosetting resin composition is an inorganic filler such as a phenol resin-based hardener, an ammonia-based hardener, etc. Additives such as the body are also possible.
The sealing material 40 may be solid or liquid at room temperature. In addition, the form of the sealing material 40 having a solid shape at room temperature is not particularly limited, and may be, for example, granular, flake, or the like.
In this embodiment, a sheet-shaped sealing material (hereinafter, also referred to as a “sheet-shaped sealing material”) is used to perform a coating process and a hardening process. In the method using the sheet-shaped sealing material, a person placing the sheet-shaped sealing material on a plurality of semiconductor wafers CP and its peripheral portion 45 is placed, and the plurality of semiconductor wafers CP and its peripheral portion are covered by the sealing material 40. 45. At this time, in the gaps between the plurality of semiconductor wafers CP, portions where the unfilled sealing material 40 is not generated are preferably vacuum-laminated or the like, and the pressure is preferably reduced while heating and pressing are performed.

As a method for covering a plurality of semiconductor wafers CP and their peripheral portions 45 through the sealing material 40, it is possible to apply any method to the semiconductor sealing process from the past, as appropriate. For example, the roller lamination method can be applied. , Vacuum stamping method, vacuum lamination method, spin coating method, mold coating method, transfer molding method, compression molding method and the like.
In these methods, in order to improve the filling properties of the sealing material 40, the sealing material 40 is heated during coating to impart fluidity.
In the aforementioned coating process, the temperature of the heat-curable resin composition varies depending on the type of the sealing material 40, the type of the adhesive sheet (D), and the like, but, for example, 30 to 180 ° C, and 50 to 170 ° C is Good, more preferably 70 ~ 150 ℃. In addition, the heating time is, for example, 5 seconds to 60 minutes, preferably 10 seconds to 45 minutes, and more preferably 15 seconds to 30 minutes.

As shown in FIG. 8 (b), the sealing material 40 is used to cover the entire surface of the plurality of semiconductor wafers CP, and at the same time, the gaps between the plurality of semiconductor wafers CP are also filled.

Next, as shown in FIG. 8 (c), after the coating process is performed, the sealing material 40 is hardened to obtain a hardened closed body 50 represented by the closed plurality of semiconductor wafers CP on the hardened sealing material 41.
In the aforementioned hardening process, the temperature at which the sealing material 40 is hardened varies depending on the type of the sealing material 40, the type of the adhesive sheet (D), and the like, but, for example, 80 to 240 ° C, and preferably 90 to 200 ° C, 100 ~ 170 ° C is more preferable. In addition, the heating time is, for example, 10 to 180 minutes, preferably 20 to 150 minutes, and more preferably 30 to 120 minutes.
Through the process (6), a hardened closed body 50 in which a plurality of semiconductor wafers CP buried in each specific distance and isolated in the hardened closed material 41 can be obtained.

[Engineering (7)]
Next, as shown in FIG. 8 (d), the adhesive sheet (D) is separated from the hardened closed body 50.
The method of separating the adhesive sheet (D) can be appropriately selected according to the type of the adhesive sheet (D). When the adhesive sheet (A) is used as the adhesive sheet (D), the expandable particles contained in the adhesive sheet (A) are separated from the hardened closed body 50 when the expandable particles contained in the adhesive sheet (A) are expanded. The conditions for expanding the expandable particles are as described in the adhesive sheet (A).

However, in this embodiment, an example has been described in which the circuit surface W1 of the plurality of semiconductor wafers CP is closed in contact with the adhesive layer (X4) of the adhesive sheet (D), but it is shown on the circuit surface W1. In the state (that is, the state where the back surface of the wafer is in contact with the adhesive layer (X4)), a sealing process can also be performed. In this case, the circuit surface W1 of the plurality of semiconductor wafers CP is covered with a sealing resin, but after curing the sealing resin, if appropriate, the hardened sealing material is cut by using a grinder or the like, and the circuit surface W1 may be expressed again .

[Engineering (8)]
9 (a) to (c) are cross-sectional views showing a process (8) of forming a redistribution layer by separating the hardened closed body 50 of the adhesive sheet (D).
FIG. 9 (b) is a cross-sectional view illustrating the process of forming the first insulating layer 61 on the circuit surface W1 of the semiconductor wafer CP and the surface 50a of the hardened closed body 50.
A first insulating layer 61 containing an insulating resin is formed on the circuit surface W1 and the surface 50a so that the internal terminal electrode W3 of the circuit W2 or the circuit W2 of the semiconductor wafer CP is exposed. Examples of the heat-resistant resin system include polyimide resin, polybenzoxazole resin, and silicone resin. The material of the internal terminal electrode W3 is not limited as long as it is a conductive material, and examples thereof include metals such as gold, silver, copper, and aluminum, and alloys including these metals.

FIG. 9C is a cross-sectional view illustrating a process of forming a rewiring 70 electrically connected to the semiconductor wafer CP sealed by the hardened sealing body 50.
In this embodiment, the rewiring 70 is formed following the formation of the first insulating layer 61. The material of the rewiring 70 is not limited as long as it is a conductive material, and examples thereof include metals such as gold, silver, copper, and aluminum, and alloys including these metals. The rewiring line 70 can be formed by a known method such as an erasing method and a semi-additive method.

FIG. 10 (a) is a cross-sectional view illustrating a process of forming the second insulating layer 62 of the covered rewiring 70. FIG.
The rewiring 70 is provided with an external electrode pad 70A for external terminal electrodes. The second insulating layer 62 is provided with an opening or the like to expose the external electrode pad 70A for the external terminal electrode. In this embodiment, the external electrode pad 70A is within the range (corresponding to the circuit surface W1 range) of the semiconductor wafer CP of the hardened closed body 50 and outside the range (corresponds to the surface 50a of the hardened closed body 50) And exposed. In addition, the rewiring 70 is formed on the surface 50 a of the hardened and sealed body 50 with the external electrode pads 70A arranged in an array. In the present embodiment, FOWLP or FOPLP can be obtained because the structure has a structure that exposes the external electrode pad 70A outside the range of the semiconductor wafer CP of the hardened closed body 50.

(Connection with external terminal electrode)
Next, if necessary, the external terminal electrode 80 may be connected to the external electrode pad 70A.
FIG. 10 (b) is a cross-sectional view illustrating a process of connecting the external terminal electrode 80 to the external electrode pad 70A.
On the external electrode pad 70A exposed from the second insulating layer 62, an external terminal electrode 80 such as a solder ball is placed, and the external terminal electrode 80 and the external electrode pad 70A are electrically connected via solder bonding or the like. The material of the solder ball is not particularly limited, and examples thereof include lead-containing solder and lead-free solder.

(Second cutting process)
FIG. 10 (c) is a cross-sectional view illustrating a second cutting process of forming the hardened closed body 50 to which the external terminal electrode 80 is connected into pieces.
In this process, the hardened closed body 50 is divided into pieces in units of a semiconductor wafer CP. The method of forming the hardened closed body 50 into individual pieces is not particularly limited, and may be implemented by a cutting means such as a cutter.
A semiconductor device 100 in a unit of a semiconductor wafer CP is manufactured by using the hardened closed body 50 as a piece. As described above, the semiconductor device 100 that connects the external terminal electrode 80 to the external electrode pad 70A outside the range of the semiconductor wafer CP is manufactured as FOWLP, FOPLP, or the like.

(Installation work)
In this embodiment, it is also preferable that a person including a semiconductor device 100 mounted on a chip to a printed wiring board is installed.

[Example]

The present invention will be specifically described by way of the following examples, but the present invention is not limited to the following examples. However, the physical property values in the following Production Examples and Examples are values measured by the following methods.

<Mass average molecular weight (Mw)>
The measurement was performed under the following conditions using a colloidal permeation chromatography apparatus (manufactured by TOSOH Co., Ltd., product name "HLC-8020"), and values measured in terms of standard polystyrene conversion were used.

(Measurement conditions)
・ Column: sequentially connect "TSK guard column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", and "TSK gel G1000HXL" (all manufactured by Japan TOSOH Corporation)
Column temperature: 40 ℃
・ Expansion solvent: tetrahydrofuran ・ Flow rate: 1.0mL / min

＜ Measurement of thickness of each layer ＞
The measurement was performed using a constant pressure thickness measuring device (model: "PG-02J", standard specification: JIS K6783, Z1702, Z1709) manufactured by TECLOCK Co., Ltd.

<Average particle diameter (D ₅₀ ), 90% particle diameter (D ₉₀ ) of thermally expandable particles>
Using a laser diffraction particle size distribution measuring device (for example, manufactured by Malvern, product name "MASTERSIZER 3000"), the particle distribution of thermally expandable particles before expansion at 23 ° C was measured.
In addition, the cumulative volume frequency calculated from the smaller particle diameter of the particle distribution is equivalent to 50% and 90% of the particle diameter, and each is made up of "average particle diameter (D ₅₀ ) of thermally expandable particles" and "90 of thermally expandable particles" % Particle diameter (D ₉₀ ).

<Storage Elasticity E 'of Expandable Base Material>
In the case where the measurement object is a non-adhesive expandable substrate, the expandable substrate is set to a size of 5 mm in length × 30 mm in width × 200 μm in thickness, and a test sample is prepared by excluding the release material.
Using a movable viscoelasticity measuring device (manufactured by TA Instruments, product name "DMAQ800"), the conditions of the test start temperature of 0 ° C, the test end temperature of 300 ° C, the temperature increase rate of 3 ° C / min, the number of vibrations of 1Hz, and the amplitude of 20μm were specified. At a temperature of 50 ° C., the storage elastic modulus E ′ of the test sample was measured.

<Shear storage modulus G 'of the adhesive layer>
In the case where the measurement object is an adhesive layer having adhesiveness, the adhesive layer is set to a diameter of 8 mm × thickness of 3 mm, and a test sample is prepared by removing the composition of the release material.
Using a viscoelasticity measuring device (manufactured by Anton Paar, device name "MCR300"), under conditions of a test start temperature of 0 ° C, a test end temperature of 300 ° C, a temperature increase rate of 3 ° C / min, and a vibration frequency of 1Hz, the torsional shear method was used. At a specific temperature, the shear storage modulus G 'of the test sample is determined. The value of the storage elastic modulus E 'is calculated based on the value of the measured shear storage modulus G' and is calculated from the approximate expression "E '= 3G'".

＜ Probe adhesion value ＞
The swellable substrate or adhesive layer to be measured is cut into a square of 10 mm on one side, and then left to stand for 24 hours in an environment of 23 ° C and 50% RH (relative humidity) to remove the constitution of the light release film. Prepare test samples.
The test sample was expressed in a 23 ° C, 50% RH (relative humidity) environment by using a seam tester (manufactured by Japan Special Tester Co., Ltd., product name "NTS-4800"), and lightly peeling off the film. Then, the probe adhesion value on the surface of the test sample was measured according to JIS Z0237: 1991.
Specifically, a stainless steel probe with a diameter of 5 mm was brought into contact with the surface of the test specimen at a contact load of 0.98 N / cm ² for 1 second, and then the probe was measured at a speed of 10 mm / sec. The force necessary for the surface to leave. In addition, the measured value is used as the probe adhesion value of this test sample.

The details of the adhesive resin, additives, thermally expandable particles, and release materials used in the formation of each layer in the following production examples are as follows.

＜ Adhesive resin ＞
・ Acrylic copolymer (i): a unit composed of a raw material monomer formed from 2-ethylhexyl acrylate (2EHA) / 2-hydroxyethyl acrylate (HEA) = 80.0 / 20.0 (mass ratio), A solution containing 600,000 acrylic copolymers. Dilution solvent: ethyl acetate, solid content concentration: 40% by mass.

＜ Additives ＞
・ Isocyanate crosslinking agent (i): manufactured by TOSOH Corporation, product name "Coronate L", solid content concentration: 75% by mass.
-Photopolymerization starter (i): BASF Corporation, product name "IRGACURE184", 1-hydroxycyclohexyl-phenyl-methanone.

＜ thermally expandable particles ＞
・ Thermally expandable particles (i): manufactured by Kureha Co., Ltd., product name "S2640", expansion start temperature (t) = 208 ° C, average particle diameter (D ₅₀ ) = 24 μm, 90% particle diameter (D ₉₀ ) = 49 μm .

＜ Peeling material ＞
・ Heavy release film: LINTEC Co., Ltd., product name "SP-PET382150", on one side of a polyethylene terephthalate (PET) film, a release agent layer formed from a silicone release agent is provided. Composition, thickness: 38 μm.
・ Light release film: LINTEC Co., Ltd., product name "SP-PET381031", the structure of a release agent layer formed from a silicone release agent on one side of the PET film, thickness: 38 μm.

Manufacturing example 1
(Formation of Adhesive Layer (X1))
In the adhesive resin, the solid content of the solution of the acrylic copolymer (i) was 100 parts by mass, and the isocyanate crosslinking agent (i) was 5.0 parts by mass (solid content ratio), and then diluted with toluene and uniformly stirred. An adhesive composition (x1) having a solid content concentration (active ingredient concentration) of 25% by mass was prepared.
Then, the prepared adhesive layer (x1) was coated on the surface of the release agent layer of the heavy release film to form a coating film, and the coating film was dried at 100 ° C. for 60 seconds to form an adhesive having a thickness of 10 μm. Layer (X1). However, at 23 ° C, the shear storage modulus G '(23) of the adhesive layer (X1) was 2.5 × 10 ⁵ Pa.

Manufacturing example 2
(Formation of Intumescent Base (Y1-1))
A terminal isocyanate urethane prepolymer obtained by reacting an ester diol with isophorone diisocyanate (IPDI) and reacting a 2-hydroxyethyl acrylate to obtain a mass average molecular weight (Mw) of 5000 A bifunctional urethane-based oligomer.
In addition, 40 mass% (solid content ratio) of isofluorenyl acrylate (IBXA) was prepared as an energy ray polymerizable monomer at 40 mass% (solid content ratio) of the urethane acrylate oligomer synthesized above. ), And 20% by mass (solid content ratio) of phenylhydroxypropyl acrylate (HPPA), and 100% by mass of the entire amount of acrylic urethane oligomer and energy ray polymerizable monomer 2.0 mass parts (solid content ratio) of the photopolymerization initiator (i) and 0.2 mass parts (solid content ratio) of a phthalocyanine pigment as an additive were blended to prepare an energy ray-curable composition. The heat-expandable particles (i) are blended in this energy ray-curable composition to prepare a solvent-free resin composition (y1) containing no solvent. However, for the total amount (100% by mass) of the resin composition (y1), the content of the thermally expandable particles (i) is 20% by mass.
Next, the prepared resin composition (y1) was applied on the surface of the release agent layer of the light release film to form a coating film. In addition, an ultraviolet irradiation device (manufactured by iGrafx, product name "ECS-401GX") and a high-pressure mercury lamp (manufactured by iGrafx, product name "H04-L41") were used under conditions of an illumination intensity of 160 mW / cm ² and a light amount of 500 mJ / cm ² Then, the coating film was cured by irradiating ultraviolet rays to form an expandable substrate (Y1-1) having a thickness of 50 μm. However, the above-mentioned illuminance and light quantity at the time of ultraviolet irradiation are the values measured using the illuminance and light quantity meter (made by EIT company, product name "UV Power Puck II").
However, the storage elastic modulus E ′ at 23 ° C. of the obtained expandable substrate (Y1-1) was 5.0 × 10 ⁸ Pa, and the storage elastic modulus E ′ at 100 ° C. was 4.0 × 10 ⁶ Pa. The storage elasticity E 'at 208 ° C is 4.0 × 10 ⁶ Pa. In addition, the probe adhesion value of the expandable substrate (Y1-1) is 2mN / 5mmf.

Manufacturing example 3
(Production of adhesive sheet (A))
The surfaces of the adhesive layer (X1) formed in Production Example 1 and the expandable substrate (Y1-1) formed in Production Example 2 were bonded to each other. As a result, an adhesive sheet (A) in which a light release film / expandable substrate (Y1-1) / adhesive layer (X1) / heavy release film is sequentially laminated is produced.

Manufacturing Example 4
(Production of adhesive sheet (B) (expansion tape))
The acrylic copolymer obtained by reacting butyl acrylate / 2-hydroxyethyl acrylate = 85/15 (mass ratio), and 80 mol% of methacrylic acid for the 2-hydroxyethyl acrylate The cyanoethyl ester (MOI) is reacted to obtain an energy ray-curable polymer. The mass average molecular weight (Mw) of this energy ray-curable polymer was 600,000. 100 mass points of the energy ray-curable polymer obtained by mixing in a solvent, and 3 mass points of 1-hydroxycyclophenyl ketone (manufactured by BASF, product name "IRGACURE184") as a photopolymerization initiator, and used as The toluene diisocyanate-based cross-linking agent (manufactured by TOSOH Corporation, product name "Coronate L") was 0.45 parts by mass to obtain an adhesive composition.
Next, a release film (product of "LINTEC Corporation, product name" SP-PET3811 ") formed by forming a polysiloxane-based release agent layer on one side of a polyethylene terephthalate (PET) film was peeled off. On the surface of the adhesive layer, an adhesive layer (X2) having a thickness of 10 μm is formed on the release film by applying the adhesive composition and drying it by heating. Then, on the exposed surface of this adhesive layer, one side of a polyester-based polyurethane elastic sheet (manufactured by Sheedom, product name “HigressDUS202”, thickness 50 μm) was bonded and peeled off as a base material (Y2). The film was in the state of the adhesive layer to obtain an adhesive sheet (B) (expansion tape).

[Manufacture of semiconductor device]
Example 1
Using the adhesive sheet (A) and the adhesive sheet (B) obtained as described above, a semiconductor device was manufactured by the following method.

＜ Engineering (1) ＞
The adhesive sheet (A) obtained in Production Example 3 was cut into a size of 230 mm × 230 mm.
The self-cutting adhesive sheet (A) peels off the heavy release film and the light release film, and attaches a ring frame and a semiconductor wafer (diameter: 150 mm, thickness: 350 μm) to the surface of the adhesive layer (X1) that appears. Next, using a dicing machine (manufactured by Disco, product name "DFD-651"), the semiconductor wafer was diced completely under the following conditions using a dicing machine. As a result, a plurality of semiconductor wafers (1800 pieces) obtained by singulation are obtained on the adhesive layer (X1) of the adhesive sheet (A).
・ Cutter: Product name "NBC-ZH2050 27HECC" manufactured by Disco
・ Number of rotations: 30,000rpm
・ Height: 0.06mm
・ 60mm / sec
・ Wafer size: 3mm × 3mm

＜ Engineering (2) ＞
The adhesive sheet (B) obtained in Production Example 4 was cut into a size of 210 mm × 210 mm. At this time, each side of the cut sheet is cut parallel or perpendicular to the MD direction of the base material (Y2) of the adhesive sheet (B). Next, the self-adhesive sheet (B) is used to peel the release sheet, and the adhesive layer (X2) of the adhesive sheet (B) is attached to the surface opposite to the surface in contact with the adhesive layer (X1) of the plurality of semiconductor wafers. ). At this time, a group of semiconductor wafers is transferred at the center of the adhesive sheet (B). In addition, when the semiconductor wafer is singulated, the cutting lines are transferred in parallel or perpendicular to the sides of the adhesive sheet (B).

＜ Engineering (3) ＞
Next, as a surface on the side opposite to the adhesive layer (X) of the expandable substrate (Y1-1) included in the adhesive sheet (A), the state of the heating plate was pressed to become the expansion start temperature of the thermally expandable particles. (208 ° C) or higher and 240 ° C, the adhesive sheet (A) is heated for 3 minutes to expand the thermally expandable particles, and the plurality of semiconductor wafers and the adhesive sheet (A) described above attached to the adhesive sheet (B) are separated. However, when the adhesive sheet (A) was separated, the adhesive sheet (A) was not bent and kept in a flat shape, and was simultaneously separated from a plurality of semiconductor wafers.

＜ Expansion Project ＞
Next, the adhesive sheet (B) to which a plurality of semiconductor wafers are attached is set in a two-axis stretchable expansion device. As shown in FIG. 11, the expansion device has an orthogonal X-axis direction (the positive direction is taken as the + X-axis direction and the negative direction is the -X-axis direction) and the Y-axis direction (the positive direction is taken as + Y The axis direction and the negative direction are referred to as a -Y axis direction), and the holding means is provided to extend in each direction (that is, + X axis direction, -X axis direction, + Y axis direction, -Y axis direction). The MD direction of the adhesive sheet (B) is matched with the X-axis or Y-axis direction, and is set in the expansion device. After holding each side of the adhesive sheet (B) through the aforementioned holding means, the adhesive is stretched under the following conditions The sheet (B) widens the interval between a plurality of semiconductor wafers attached to the adhesive layer (X2) of the adhesive sheet (B).
・ Number of holding means: Near one side, 5 ・ Extending speed: 5mm / sec
・ Extended distance: each side is extended by 60mm.

Comparative Example 1
＜ Engineering (1) ＞
A ring is attached to the surface of an adhesive layer of a dicing tape (manufactured by LINTEC Corporation, trade name "D-820") (hereinafter also referred to as "comparative dicing tape") having a base material and an adhesive layer. Frame and semiconductor wafer (diameter: 150 mm, thickness: 350 μm). After that, the same procedure as in the process (1) of Example 1 was performed to obtain a plurality of semiconductor wafers each divided into pieces.

＜ Engineering (2) ＞
This was carried out in the same manner as in Example 1.

＜ Engineering (3) ＞
From the side of the substrate side of the dicing tape for comparison, an ultraviolet irradiance of 230 mW / cm ² and a light amount of 190 mJ / cm ^{2 were} irradiated to harden the adhesive layer, and the plurality of semiconductor wafers attached to the adhesive sheet (B) were separated and compared Cutting tape. However, when the comparative dicing tape was separated, the comparative dicing tape was not bent and kept in a flat shape, and was simultaneously separated from a plurality of semiconductor wafers.

＜ Expansion Project ＞
This was carried out in the same manner as in Example 1.

[Evaluation of wafer defect]
The appearance of the plurality of expanded semiconductor wafers obtained as described above was observed with a microscope, the presence or absence of wafer defects in the semiconductor wafer was confirmed, and evaluation was performed on the following basis.
・ A: Structure with wafer defect.
・ F: Structure without wafer defects.

[Measurement of adhesive force of adhesive sheet]
(Adhesion measurement before and after heating of the adhesive sheet (A))
The light release film of the produced adhesive sheet (A) was removed. Next, the heavy release film of the adhesive sheet (A) was also removed, and the adhesive surface of the adhesive layer (X1) exhibited was adhered to the stainless steel plate (SUS304 360) polished at 23 ° C, A 50% RH (relative humidity) environment was left to stand for 24 hours as a test sample.
Using the above test sample, the adhesive force at 23 ° C. was measured at a tensile speed of 300 mm / min through a 180 ° peeling method in an environment of 23 ° C. and 50% RH (relative humidity) in accordance with JIS Z0237: 2000.
In addition, the above-mentioned test sample was heated on a hot plate at 240 ° C higher than the expansion temperature of thermally expandable particles (208 ° C) for 3 minutes, and then heated in a standard environment (23 ° C, 50% RH (relative humidity)). ) After standing for 60 minutes, the adhesive force after heating at a temperature equal to or higher than the expansion start temperature was measured under the same conditions as above.

(Adhesion measurement before and after UV irradiation of a comparison dicing tape)
The adhesive surface of a comparative cutting tape (manufactured by LINTEC Co., Ltd. under the trade name "D-820") was attached to a stainless steel plate (SUS304 360 No. polished) of the adherend, and the temperature was measured at 23 ° C and 50% RH (relative to In a humidity) environment, the composition was left to stand for 24 hours. As a test sample, the adhesion force at 23 ° C. before ultraviolet irradiation was measured under the same conditions as the adhesive sheet (A).
Next, from the base material side of the comparison dicing tape, an ultraviolet irradiance of 230 mW / cm ² and a light amount of 190 mJ / cm ^{2 were} irradiated, and then the adhesive force at 23 ° C. after ultraviolet irradiation was measured under the same conditions as above.

From the results in Table 1, the adhesive strength of the adhesive sheet (A) used in the manufacturing method of this embodiment is smaller than that of the conventional ultraviolet irradiated adhesive sheet, and the semiconductor wafer can be obtained by cutting the wafer through this. The plurality of wafers can be easily transferred to another adhesive sheet, and it has been found that the occurrence of wafer defects during transfer can be effectively suppressed.

1a‧‧‧Adhesive sheet (a)

1b‧‧‧ Adhesive sheet (a)

40‧‧‧ Closure

41‧‧‧hardened sealing material

45‧‧‧ Peripheral part of semiconductor wafer CP

50‧‧‧ hardened closed body

50a‧‧‧ surface

61‧‧‧The first insulation layer

62‧‧‧Second insulation layer

70‧‧‧ rewiring

70A‧‧‧External electrode gasket

80‧‧‧ external terminal electrode

100‧‧‧ semiconductor device

200‧‧‧Expansion device

210‧‧‧ Means of retention

CP‧‧‧Semiconductor wafer

W1‧‧‧Circuit Surface

W2‧‧‧Circuit

W3‧‧‧Internal terminal electrode

FIG. 1 is a cross-sectional view showing an example of the configuration of an adhesive sheet (A) used in the manufacturing method of the present embodiment, (a) an adhesive sheet a1, and (b) an adhesive sheet b1.

FIG. 2 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment.

FIG. 3 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 2.

FIG. 4 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 3.

FIG. 5 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 4.

FIG. 6 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 5.

FIG. 7 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 6.

FIG. 8 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 7.

FIG. 9 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 8.

FIG. 10 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment, following FIG. 9.

Fig. 11 is a plan view illustrating a two-axis extension and expansion device used in the embodiment.

Claims (11)

A method for manufacturing a semiconductor device is a method for manufacturing a semiconductor device using a substrate (Y1) and an adhesive layer (X1), in which any layer contains expandable particles and an expandable adhesive sheet (A). for Manufacturing method of semiconductor device having the following processes (1) to (3) in sequence; Process (1): After attaching the processed object to the adhesive layer (X1) of the adhesive sheet (A), cutting the processed object to obtain a plurality of wafers that are sliced on the adhesive layer (X1) , Process (2): using an adhesive sheet (B) having a base material (Y2) and an adhesive layer (X2), the surface on the side opposite to the surface to which the adhesive layer (X1) of the plurality of wafers is bonded, and attaching Engineering of the adhesive layer (X2) of the adhesive sheet (B), Process (3): A process of expanding the expandable particles and separating the plurality of wafers and the adhesive sheet (A) attached to the adhesive sheet (B). For example, the method for manufacturing a semiconductor device described in item 1 of the scope of patent application, wherein the adhesive sheet (B) is an adhesive sheet for expansion, and after the process (3), it further has the following process (4A); Process (4A): A process of expanding the interval between the plurality of wafers attached to the adhesive sheet (B) by stretching the adhesive sheet (B). For example, the method for manufacturing a semiconductor device described in item 1 of the scope of patent application, in which an expansion sheet (C) having a base material (Y3) and an adhesive layer (X3) is used to further perform the following process (4B-1 ) ~ (4B-3), Process (4B-1): A process of attaching the adhesive layer (X3) of the adhesive sheet (C) on the side opposite to the surface to which the adhesive layer (X2) of the plurality of wafers on the adhesive sheet (B) is bonded , Process (4B-2): The process of separating the plurality of wafers attached to the adhesive sheet (C), separating the adhesive sheet (B), Process (4B-3): A process of expanding the interval between the plurality of wafers attached to the adhesive sheet (C) by stretching the adhesive sheet (C). For example, the method for manufacturing a semiconductor device described in item 2 or 3 of the scope of patent application, wherein the expansion sheet is measured in the MD direction and the CD direction at 23 ° C, and the elongation at break is 100% or more. . For example, the method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein the aforementioned expandable particles are thermally expandable particles whose expansion start temperature (t) is 60 to 270 ° C, and the aforementioned process ( 3) The process of separating the plurality of wafers attached to the adhesive sheet (B) and the adhesive sheet (A) by heating the adhesive sheet (A). For example, the method for manufacturing a semiconductor device according to any one of claims 1 to 5 in the scope of the patent application, wherein the process (1) includes a process of stretching the adhesive sheet (A) after cutting the object to be processed. The method for manufacturing a semiconductor device according to any one of claims 1 to 6, in which the adhesive layer (X1) of the adhesive sheet (A) is measured at 23 ° C before expansion of the expandable particles. The adhesive force is 0.1 ~ 10.0N / 25mm. For example, the method for manufacturing a semiconductor device according to any one of claims 1 to 7, wherein the probe adhesion value on the surface of the substrate (Y1) of the adhesive sheet (A) is less than 50 mN / 5 mmf. The method for manufacturing a semiconductor device according to any one of claims 1 to 8 in the scope of the patent application, wherein the substrate (Y1) included in the adhesive sheet (A) is an expandable substrate (Y1) containing the aforementioned expandable particles. -1). According to the method for manufacturing a semiconductor device according to any one of claims 1 to 9, in the patent application scope, wherein the processed object is a semiconductor wafer. For example, the method for manufacturing a semiconductor device described in item 10 of the scope of patent application is a method for manufacturing a fan-out type semiconductor device.