JPWO2019098101A1 - Manufacturing method of semiconductor devices - Google Patents

Abstract

A semiconductor device having the following steps (1) to (3) in this order, and after the step (3), the expansive particles of the pressure-sensitive adhesive sheet (A) are expanded to separate the pressure-sensitive adhesive sheet (A) from the adherend. Regarding the manufacturing method of. Step (1): The distance between the plurality of semiconductor chips placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2) is set by the pressure-sensitive adhesive sheet (B). ) Is stretched and expanded. Step (2): A step of attaching the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) to the surface of the plurality of semiconductor chips opposite to the surface in contact with the pressure-sensitive adhesive layers (X2). Step (3): A step of separating the plurality of semiconductor chips attached to the adhesive sheet (A) from the adhesive sheet (B).

Description

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

In recent years, electronic devices have become smaller, lighter, and more sophisticated, and along with this, semiconductor devices mounted on electronic devices are also required to be smaller, thinner, and higher in density.
Semiconductor chips may be mounted in packages close to their size. Such a package is sometimes called a CSP (Chip Scale Package). Examples of the CSP include WLP (Wafer Level Package), which processes and completes the final package process with a wafer size, and PLP (Panel Level Package), which processes and completes the package final process with a panel size larger than the wafer size. ..

WLP and PLP are classified into fan-in type and fan-out type. In fan-out type WLP (hereinafter, also referred to as “FOWLP”) and PLP (hereinafter, also referred to as “FOPLP”), the semiconductor chip is covered with a sealing material so as to have a region larger than the chip size. The encapsulant is formed, and the rewiring layer and the external electrode are formed not only on the circuit surface of the semiconductor chip but also on the surface region of the encapsulant.
For example, in Patent Document 1, a plurality of semiconductor chips separated from a semiconductor wafer are surrounded by a mold member to form an expansion wafer, leaving the circuit forming surface thereof, and in a region outside the semiconductor chip. A method for manufacturing a semiconductor package formed by extending a rewiring pattern is described. In the manufacturing method described in Patent Document 1, the semiconductor wafer is subjected to a dicing step in which the semiconductor wafer is individualized while being attached to a wafer mount tape for dicing (hereinafter, also referred to as “dicing tape”). The plurality of semiconductor chips obtained in the dicing step are transferred to a wafer mount tape for expanding (hereinafter, also referred to as "expanding tape"), and the expanding tape is spread to increase the distance between the plurality of semiconductor chips. It is subjected to an expanding process.

The expanding tape is used in the manufacturing process of a semiconductor device to widen the distance between chips obtained by dicing individual pieces of a workpiece, and in addition to the above-mentioned semiconductor chips, for example, an LED ( It can also be used to widen the distance between chips obtained by dicing Light Emitting Diode), MEMS (Micro Electro Mechanical Systems), ceramic devices, semiconductor packages, semiconductor devices having a plurality of devices, and the like. In either case, the plurality of chips spaced apart on the expanding tape need to be separated from the expanding tape for use in the next step. Specifically, for example, the semiconductor chip subjected to the expanding step is then subjected to a step of being sealed with a sealing resin, but since the sealing resin is usually a thermosetting resin, it is sealed. From the viewpoint of suppressing thermal deformation during the stopping process, it is preferable to move the semiconductor chip to an adhesive sheet (hereinafter, also referred to as “temporary fixing sheet”) having higher heat resistance than the expanding tape.
As a method of moving the chip to another adhesive sheet such as a temporary fixing sheet, a method of transferring the chip directly from the expanding tape to another adhesive sheet may be used, and the chip is once separated from the expanding tape and the chip is separated. It may be a method of transferring to another pressure-sensitive adhesive sheet after being subjected to the rearrangement step of aligning.
Since the expanding tape is separated from the chips after widening the space between the chips, an energy ray-curable adhesive or the like that is cured by energy ray irradiation and the adhesive strength is lowered is used.

International Publication No. 2010/058646

Expanded tapes that use an energy ray-curable adhesive can reduce the adhesive strength by irradiation with energy rays, but the chip and the adhesive layer are adhered to the entire adhesive surface even after irradiation with energy rays, so to some extent. Adhesive strength remains. Therefore, when separating the chips from the expanding tape, it is necessary to pick up the chips one by one or transfer them to the adhesive sheet all at once.
For example, when the chips are subjected to the above rearrangement step, it is difficult to move the individualized chips to the arrangement jig all at once, so that it is necessary to pick up the chips one by one. It is complicated and inferior in productivity.
On the other hand, when transferring from an expanding tape to another adhesive sheet, although a plurality of chips can be moved at once, another adhesive sheet is a conventional adhesive sheet of a type that reduces the adhesive force by irradiation with energy rays. As described above, since a certain amount of adhesive force remains even after irradiation with energy rays, a certain external force is required when separating another adhesive sheet from the chip, which requires a complicated device or the chip. There may be a problem with cleanliness due to adhesive residue. This problem is the same when the above-mentioned temporary fixing sheet is used as another adhesive sheet. In that case, a cured sealant in which the semiconductor chip is sealed with a sealing resin on the temporary fixing sheet. And, when separating the temporary fixing sheet, the above-mentioned complicated device may be required, or a problem may occur in the cleanliness of the obtained cured sealant.

The present invention has been made in view of the above problems, and the chips whose intervals have been widened by the expanding step can be easily separated from the expanding tape all at once while maintaining the intervals, and can be separated. An object of the present invention is to provide a method for manufacturing a semiconductor device capable of easily using the chip to be used in the next process.

The present inventors are a method for manufacturing a semiconductor device using an expandable pressure-sensitive adhesive sheet having a base material containing expandable particles and a pressure-sensitive adhesive layer, and have specific steps (1) to (3) in this order. Then, it has been found that the above-mentioned problems can be solved by a manufacturing method in which the expansive particles of the pressure-sensitive adhesive sheet are expanded after the step (3) to separate the pressure-sensitive adhesive sheet from the adherend.
That is, the present invention relates to the following [1] to [10].
[1] A method for manufacturing a semiconductor device using an expandable pressure-sensitive adhesive sheet (A) having a base material (Y1) containing expandable particles and a pressure-sensitive adhesive layer (X1).
A semiconductor device having the following steps (1) to (3) in this order, and after the step (3), the expansive particles of the pressure-sensitive adhesive sheet (A) are expanded to separate the pressure-sensitive adhesive sheet (A) from the adherend. Manufacturing method.
Step (1): The distance between a plurality of chips placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2) is set by the pressure-sensitive adhesive sheet (B). The process of stretching and spreading.
Step (2): A step of attaching the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) to the surface of the plurality of chips opposite to the surface in contact with the pressure-sensitive adhesive layers (X2).
Step (3): A step of separating the plurality of chips attached to the adhesive sheet (A) from the adhesive sheet (B).
[2] The expandable particles are thermally expandable particles having an expansion start temperature (t) of 60 to 270 ° C., and the heat-expandable particles are formed by heating the pressure-sensitive adhesive sheet (A) after the step (3). The method for manufacturing a semiconductor device according to the above [1], wherein the pressure-sensitive adhesive sheet (A) is separated from an adherend by expanding it.
[3] The above [1] or [2], wherein the adhesive force of the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) before expanding the expandable particles is 0.1 to 10.0 N / 25 mm. The method for manufacturing a semiconductor device according to.
[4] The method for manufacturing a semiconductor device according to any one of [1] to [3] above, wherein the probe tack value on the surface of the base material (Y1) of the pressure-sensitive adhesive sheet (A) is less than 50 mN / 5 mmφ.
[5] The method for manufacturing a semiconductor device according to any one of the above [1] to [4], wherein the chip is a semiconductor chip.
[6] The method for manufacturing a semiconductor device according to the above [5], further comprising the following steps (4A-1) to (4A-3).
Step (4A-1): The plurality of semiconductor chips and the peripheral portion of the plurality of semiconductor chips on the adhesive surface of the pressure-sensitive adhesive layer (X1) are covered with a sealing material, and the sealing material is cured. A step of obtaining a cured sealant obtained by sealing the plurality of semiconductor chips with a cured sealant.
Step (4A-2): A step of expanding the expandable particles to separate the pressure-sensitive adhesive sheet (A) from the cured sealant.
Step (4A-3): A step of forming a rewiring layer on the cured seal body from which the adhesive sheet (A) has been separated.
[7] The method for manufacturing a semiconductor device according to the above [5], further comprising the following steps (4B-1) and (4B-2).
Step (4B-1): A step of expanding the expandable particles to separate the pressure-sensitive adhesive sheet (A) from the plurality of semiconductor chips.
-Step (4B-2): A step of aligning the plurality of semiconductor chips separated from the adhesive sheet (A).
[8] The step (4B-2) is a step of aligning the plurality of semiconductor chips separated from the pressure-sensitive adhesive sheet (A) by using an alignment jig provided with a plurality of accommodating portions capable of accommodating the plurality of semiconductor chips. The method for manufacturing a semiconductor device according to the above [7].
[9] The manufacture of the semiconductor device according to any one of [1] to [8] above, wherein the pressure-sensitive adhesive sheet (B) has a breaking elongation of 100% or more measured in the MD direction and the CD direction at 23 ° C. Method.
[10] The method for manufacturing a semiconductor device according to any one of the above [1] to [9], which is a method for manufacturing a fan-out type semiconductor device.

According to the present invention, chips whose intervals have been widened by the expanding step can be easily separated from the expanding tape all at once while maintaining the intervals, and the separated chips can be easily used in the next step. A method for manufacturing a semiconductor device can be provided.

It is sectional drawing of the double-sided adhesive sheet which shows an example of the structure of the double-sided adhesive sheet which concerns on this embodiment. It is sectional drawing explaining an example of the manufacturing method which concerns on this Embodiment. It is sectional drawing which describes an example of the manufacturing method which concerns on this Embodiment following FIG. FIG. 3 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. FIG. 4 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. 5 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. FIG. 6 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. FIG. 7 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. 7. FIG. 8 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. FIG. 9 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. FIG. 6 is a cross-sectional view illustrating an example of the manufacturing method according to the present embodiment following FIG. It is sectional drawing explaining an example of the manufacturing method which concerns on this Embodiment. It is sectional drawing explaining an example of the manufacturing method which concerns on this Embodiment. It is a top view explaining the biaxial stretching expanding apparatus used in an Example.

As used herein, the term "active ingredient" refers to a component contained in a target composition excluding a diluting solvent.
The mass average molecular weight (Mw) is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method, and specifically, a value measured based on the method described in Examples.

In the present specification, for example, "(meth) acrylic acid" means both "acrylic acid" and "methacrylic acid", and other similar terms are also used.
Further, with respect to a preferable numerical range (for example, a range such as content), the lower limit value and the upper limit value described stepwise can be combined independently. For example, from the description of "preferably 10 to 90, more preferably 30 to 60", the "preferable lower limit value (10)" and the "more preferable upper limit value (60)" are combined to obtain "10 to 60". You can also do it.

In the present specification, "transfer of a chip" means that the exposed surface of the chip attached to one of the adhesive sheets is attached to the other adhesive sheet, and then the one adhesive sheet is separated from the chip. Then, the operation of moving the chip from one adhesive sheet to the other adhesive sheet is referred to.

The method for manufacturing a semiconductor device according to the present embodiment is a method for manufacturing a semiconductor device using an expandable pressure-sensitive adhesive sheet (A) having a base material (Y1) containing expandable particles and an adhesive layer (X1).
A semiconductor device having the following steps (1) to (3) in this order, and after the step (3), the expansive particles of the pressure-sensitive adhesive sheet (A) are expanded to separate the pressure-sensitive adhesive sheet (A) from the adherend. It is a manufacturing method of.
Step (1): The distance between a plurality of chips placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2) is set by the pressure-sensitive adhesive sheet (B). The process of stretching and spreading.
Step (2): A step of attaching the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) to the surface of the plurality of chips opposite to the surface in contact with the pressure-sensitive adhesive layers (X2).
Step (3): A step of separating the plurality of chips attached to the adhesive sheet (A) from the adhesive sheet (B).
The "chip" used in the present embodiment means an individualized work piece, and the work piece in the present embodiment is, for example, a semiconductor wafer, an LED (Light Emitting Diode), or a MEMS (MEMS). Micro Electro Mechanical Systems), ceramic devices, semiconductor packages, wafers with multiple devices, etc., which are diced in the manufacturing process of semiconductor devices.
Hereinafter, the pressure-sensitive adhesive sheet (A) used in the manufacturing method of the present embodiment will be described first, and then each manufacturing process including the steps (1) to (3) will be described.

[Adhesive sheet (A)]
The pressure-sensitive adhesive sheet (A) is an expandable pressure-sensitive adhesive sheet having a base material (Y1) containing expandable particles and a pressure-sensitive adhesive layer (X1).
The pressure-sensitive adhesive sheet (A) can maintain high adhesiveness of the pressure-sensitive adhesive layer (X1) before expanding the expandable particles. Therefore, by attaching the pressure-sensitive adhesive layer (X1) to the exposed surfaces of the plurality of chips on the expanding tape, the plurality of chips are firmly held on the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A). As a result, the expanding tape can be easily separated from the chips firmly held on the pressure-sensitive adhesive layer (X1) all at once without causing the chips to fall off. On the other hand, when the pressure-sensitive adhesive sheet (A) and the chip are separated, the pressure-sensitive particles are expanded to form irregularities on the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer (X1). The contact area between the particle and the chip can be reduced, and the adhesive strength can be significantly reduced. As a result, when the pressure-sensitive adhesive sheet (A) and the chip are separated, there is no adhesive residue on the chip, and the adhesive sheet (A) can be easily separated at once while maintaining its cleanliness.

1 (a) and 1 (b) are schematic cross-sectional views of the pressure-sensitive adhesive sheet 1a and the pressure-sensitive adhesive sheet 1b, which are one aspect of the pressure-sensitive adhesive sheet (A).

The pressure-sensitive adhesive sheet 1a shown in FIG. 1A has a pressure-sensitive adhesive layer (X1) on one surface of the base material (Y1). The pressure-sensitive adhesive sheet 1a facilitates separation between the expanding tape and the chip by attaching the pressure-sensitive adhesive layer (X1) to the chip on the expanding tape and holding the chip on the pressure-sensitive adhesive layer (X1). .. When the pressure-sensitive adhesive sheet 1a and the chip are separated, the expansive particles in the base material (Y1) are expanded to generate irregularities on the surface of the pressure-sensitive adhesive layer (X1) in contact with the chip, and the pressure-sensitive adhesive layer (Y1) is separated. Separation at the interface between X1) and the chip can be facilitated.

The pressure-sensitive adhesive sheet 1b shown in FIG. 1B has a pressure-sensitive adhesive layer (X1) on one surface of the base material (Y1) and a non-expandable base material (Y1') on the other side. The pressure-sensitive adhesive sheet 1b is used in the same manner as the pressure-sensitive adhesive sheet 1a, but when the expandable particles in the base material (Y1) are expanded, the non-expandable base material (Y1') is present. , It is possible to suppress the occurrence of unevenness on the surface of the base material (Y1) on the non-expandable base material (Y1') side, thereby making the unevenness on the surface of the pressure-sensitive adhesive layer (X1) side more efficient. Can be formed.

The structure of the pressure-sensitive adhesive sheet (A) is not limited to the structure shown in FIGS. 1 (a) and 1 (b), and for example, another structure is provided between the base material (Y1) and the pressure-sensitive adhesive layer (X1). It may have a structure having layers. However, from the viewpoint of forming a pressure-sensitive adhesive sheet that can be separated with a slight force, it is preferable to have a structure in which the base material (Y1) and the pressure-sensitive adhesive layer (X1) are directly laminated. Further, the base material (Y1) may have another pressure-sensitive adhesive layer on the surface opposite to the pressure-sensitive adhesive layer (X1).
Further, the pressure-sensitive adhesive sheet (A) may have a release material on the pressure-sensitive adhesive layer (X1). The release material is appropriately peeled off when the pressure-sensitive adhesive sheet (A) is used in the manufacturing method according to the present embodiment.
The shape of the adhesive sheet (A) can be any shape such as a sheet shape, a tape shape, and a label shape.

(Base material (Y1))
The base material (Y1) contained in the pressure-sensitive adhesive sheet (A) is a non-sticky base material containing expansive particles.
In the present invention, whether or not the substrate is a non-adhesive substrate is determined if the probe tack value measured in accordance with JIS Z0237: 1991 with respect to the surface of the substrate of interest is less than 50 mN / 5 mmφ. The base material is judged to be a "non-adhesive base material".
Here, the probe tack value on the surface of the base material (Y1) used in the present embodiment is usually less than 50 mN / 5 mmφ, but preferably less than 30 mN / 5 mmφ, more preferably less than 10 mN / 5 mmφ, still more preferably 5 mN. It is less than / 5 mmφ.
In this specification, the specific method for measuring the probe tack value on the surface of the base material (Y1) is the method described in Examples.

In the pressure-sensitive adhesive sheet (A), since the expandable particles are contained not in the pressure-sensitive adhesive layer but in the non-adhesive resin having a high elastic modulus, the thickness of the pressure-sensitive adhesive layer (X1) on which the chips are placed can be adjusted and the adhesive strength can be adjusted. , Control of viscoelasticity, etc., improves the degree of freedom in design. As a result, the occurrence of chip misalignment can be suppressed. Further, when the pressure-sensitive adhesive sheet (A) is used, the chip is placed on the pressure-sensitive surface of the pressure-sensitive adhesive layer (X1), so that the base material (Y1) containing the expandable particles does not come into direct contact with the chip. .. As a result, the residue derived from the expandable particles and a part of the greatly deformed pressure-sensitive adhesive layer are prevented from adhering to the chip, and the uneven shape formed on the expandable pressure-sensitive adhesive layer is suppressed from being transferred to the chip, thereby improving the cleanliness. The chip can be used for the next step while being maintained.

The thickness of the base material (Y1) is preferably 10 to 1000 μm, more preferably 20 to 500 μm, still more preferably 25 to 400 μm, and even more preferably 30 to 300 μm.
In this specification, the thickness of the base material (Y1) means a value measured by the method described in Examples.

The base material (Y1) can be formed from the resin composition (y1). Hereinafter, each component contained in the resin composition (y1), which is a material for forming the base material (Y1), will be described.

[Expandable particles]
The pressure-sensitive adhesive sheet (A) contains expansive particles in the base material (Y1).
The expandable particles are particularly limited as long as they can expand themselves by an external stimulus to form irregularities on the adhesive surface of the adhesive layer (X1) and reduce the adhesive force with the adherend. Not done.
Examples of the expandable particles include thermal-expandable particles that expand by heating, energy-ray-expandable particles that expand by irradiation with energy rays, and the like. Is preferable.

The expansion start temperature (t) of the heat-expandable particles is preferably 60 to 270 ° C, more preferably 70 to 260 ° C, and even more preferably 80 to 250 ° C.
In addition, in this specification, the expansion start temperature (t) of a heat-expandable particle means a value measured based on the following method.
[Measurement method of expansion start temperature (t) of thermally expandable particles]
To an aluminum cup with a diameter of 6.0 mm (inner diameter 5.65 mm) and a depth of 4.8 mm, 0.5 mg of the heat-expandable particles to be measured were added, and an aluminum lid (diameter 5.6 mm, thickness 0. A sample on which 1 mm) is placed is prepared.
Using a dynamic viscoelasticity measuring device, the height of the sample is measured with a force of 0.01 N applied by a pressurizer from the upper part of the aluminum lid to the sample. And. With a force of 0.01 N applied by the pressurizer, it is heated from 20 ° C. to 300 ° C. at a heating rate of 10 ° C./min, the amount of displacement of the pressurizer in the vertical direction is measured, and displacement in the positive direction is started. Let the temperature be the expansion start temperature (t).

The heat-expandable particles are microencapsulated foaming agents composed of an outer shell made of a thermoplastic resin and an contained component contained in the outer shell and vaporized when heated to a predetermined temperature. It is preferable to have.
Examples of the thermoplastic resin constituting the outer shell of the microencapsulating foaming agent include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethylmethacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone and the like.

Examples of the contained components contained in the outer shell include propane, butane, pentane, hexane, heptane, octane, nonane, decane, isobutane, isopentane, isohexane, isoheptan, isooctane, isononan, isodecane, cyclopropane, cyclobutane, and cyclopentane. , Cyclohexane, cycloheptan, cyclooctane, neopentane, dodecane, isododecane, cyclotridecane, hexylcyclohexane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nanodecane, isotoridecan, 4-methyldodecane, isotetradecane, isopentadecane, iso Hexadecane, 2,2,4,4,6,8,8-heptamethylnonane, isoheptadecane, isooctadecane, isonanodecane, 2,6,10,14-tetramethylpentadecane, cyclotridecane, heptylcyclohexane, n-octylcyclohexane , Cyclopentadecane, nonylcyclohexane, decylcyclohexane, pentadecylcyclohexane, hexadecylcyclohexane, heptadecylcyclohexane, octadecylcyclohexane and the like. These inclusion components 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 inclusion component.

The maximum volume expansion coefficient when the thermally expandable particles are heated to a temperature equal to or higher than the thermal expansion start temperature (t) is preferably 1.5 to 100 times, more preferably 2 to 80 times, still more preferably 2.5 to. It is 60 times, more preferably 3 to 40 times.

The average particle size 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.
The average particle size of the expandable particles before expansion is the volume medium particle size (D ₅₀ ), and a laser diffraction type particle size distribution measuring device (for example, manufactured by Malvern, product name “Mastersizer 3000”) is used. It means the particle diameter corresponding to 50% of the cumulative volume frequency calculated from the smaller particle diameter of the expandable particles before expansion in the particle distribution of the expandable particles before expansion measured by using.

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, still more preferably 30 to 80 μm. ..
The 90% particle size (D ₉₀ ) of the expandable particles before expansion is measured using a laser diffraction type particle size distribution measuring device (for example, manufactured by Malvern, product name “Mastersizer 3000”), and is measured before expansion. In the particle distribution of the expansive particles of the above, it means the particle size in which the cumulative volume frequency calculated from the smaller particle size of the particle size of the expansive particles before expansion corresponds to 90%.

The content of the expandable particles is preferably 1 to 40% by mass, more preferably 5 to 35% by mass, still more preferably 10 to 30% with respect to the total amount (100% by mass) of the active ingredient of the base material (Y1). It is by mass, more preferably 15 to 25% by mass.

〔resin〕
The resin contained in the resin composition (y1) is not particularly limited as long as the base material (Y1) is a non-adhesive resin, and may be a non-adhesive resin or an adhesive resin. Good. That is, even if the resin contained in the resin composition (y1) is an adhesive resin, the adhesive resin reacts with the polymerizable compound in the process of forming the base material (Y1) from the resin composition (y1). The obtained resin may be a non-adhesive resin, and the base material (Y1) containing the resin may be non-adhesive.

The mass average molecular weight (Mw) of the resin contained in the resin composition (y1) is preferably 1,000 to 1,000,000, more preferably 1,000 to 700,000, and even more preferably 1,000 to 500,000. ..
When the resin is a copolymer having two or more kinds of structural units, the form of the copolymer is not particularly limited, and it may be a block copolymer, a random copolymer, or a graft copolymer. May be good.

The content of the resin is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, still more preferably 65 to 90% with respect to the total amount (100% by mass) of the active ingredient of the resin composition (y1). It is by mass, more preferably 70 to 85% by mass.

The resin contained in the resin composition (y1) preferably contains one or more selected from acrylic urethane-based resins and olefin-based resins. As the acrylic urethane resin, an acrylic urethane resin (U1) obtained by polymerizing a urethane prepolymer (UP) and a vinyl compound containing a (meth) acrylic acid ester is preferable.

[Acrylic urethane resin (U1)]
Examples of the urethane prepolymer (UP) that serves as the main chain of the acrylic urethane resin (U1) include a reaction product of a polyol and a multivalent isocyanate.
The urethane prepolymer (UP) is preferably obtained by further performing a chain extension reaction using a chain extender.

Examples of the polyol which is a raw material of the urethane prepolymer (UP) include an alkylene type polyol, an ether type polyol, an ester type polyol, an ester amide type polyol, an ester ether type polyol, and a carbonate type polyol.
These polyols may be used alone or in combination of two or more.
As the polyol used in the present embodiment, a diol is preferable, an ester type diol, an alkylene type diol and a carbonate type diol are more preferable, and an ester type diol and a carbonate type diol are further preferable.

Examples of the ester-type diol include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol; ethylene glycol, propylene glycol, and the like. One or more selected from diols such as diethylene glycol, alkylene glycol such as dipropylene glycol; and phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, diphenylmethane- 4,4'-Dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, hetic acid, maleic acid, fumaric acid, itaconic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, Examples thereof include dicarboxylic acids such as hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, and methylhexahydrophthalic acid, and one or more selected from these anhydrides.
Specifically, polyethylene adipatediol, polybutylene adipatediol, polyhexamethylene adipatediol, polyhexamethyleneisophthalatediol, polyneopentyl adipatediol, polyethylenepropylene adipatediol, polyethylenebutylene adipatediol, polybutylenehexamethylene adipatediol, Polydiethylene adipate diol, poly (polytetramethylene ether) adipate diol, poly (3-methylpentylene adipate) diol, polyethylene azelate diol, polyethylene sebacate diol, polybutylene azelate diol, polybutylene sebacate diol, polyneo Examples thereof include pentyl terephthalate diol.

Examples of the alkylene-type diol include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol; ethylene glycol, propylene glycol, and the like. Examples thereof include alkylene glycols such as diethylene glycol and dipropylene glycol; polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polybutylene glycol; and polyoxyalkylene glycols such as polytetramethylene glycol.

Examples of the carbonate type diol include 1,4-tetramethylene carbonate diol, 1,5-pentamethylene carbonate diol, 1,6-hexamethylene carbonate diol, 1,2-propylene carbonate diol, and 1,3-propylene carbonate diol. , 2,2-Dimethylpropylene carbonate diol, 1,7-heptamethylene carbonate diol, 1,8-octamethylene carbonate diol, 1,4-cyclohexane carbonate diol and the like.

Examples of the polyisocyanate used as a raw material for the urethane prepolymer (UP) include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.
These multivalent isocyanates may be used alone or in combination of two or more.
Further, these polyvalent isocyanates may be a trimethylolpropane adduct-type modified product, a biuret-type modified product reacted with water, or an isocyanurate-type modified product containing an isocyanurate ring.
Among these, diisocyanate is preferable as the polyvalent isocyanate used in the present embodiment, and 4,4'-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), and 2,6-triisocyanate are preferable. More preferably, one or more selected from range isocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI), and alicyclic diisocyanate.

Examples of the alicyclic diisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexylisocyanate (isophorone diisocyanate, IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexanediisocyanate, and 1,4-cyclohexane. Examples thereof include diisocyanate, methyl-2,4-cyclohexanediisocyanate and methyl-2,6-cyclohexanediisocyanate, but isophorone diisocyanate (IPDI) is preferable.

In the present embodiment, the urethane prepolymer (UP) serving as the main chain of the acrylic urethane resin (U1) is a reaction product of a diol and a diisocyanate, and is a linear urethane prepolymer having ethylenically unsaturated groups at both ends. Polymers are preferred.
As a method of introducing an ethylenically unsaturated group into both ends of the linear urethane prepolymer, an NCO group at the terminal of the linear urethane prepolymer formed by reacting a diol and a diisocyanate compound and a hydroxyalkyl (meth) acrylate There is a method of reacting with.
Examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxy. Examples thereof include butyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate.

The vinyl compound that forms the side chain of the acrylic urethane resin (U1) contains at least (meth) acrylic acid ester.
As the (meth) acrylic acid ester, one or more selected from alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate is preferable, and alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate are more preferably used in combination.
When alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate are used in combination, the blending ratio of hydroxyalkyl (meth) acrylate to 100 parts by mass of alkyl (meth) acrylate is preferably 0.1 to 100 parts by mass. It is preferably 0.5 to 30 parts by mass, more preferably 1.0 to 20 parts by mass, and even more preferably 1.5 to 10 parts by mass.

The number of carbon atoms of the alkyl group contained in the alkyl (meth) acrylate is preferably 1 to 24, more preferably 1 to 12, still more preferably 1 to 8, and even more preferably 1 to 3.
Examples of the hydroxyalkyl (meth) acrylate include the same hydroxyalkyl (meth) acrylates used for introducing ethylenically unsaturated groups at both ends of the above-mentioned linear urethane prepolymer.

Examples of vinyl compounds other than (meth) acrylic acid ester include aromatic hydrocarbon-based vinyl compounds such as styrene, α-methylstyrene and vinyltoluene; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; vinyl acetate and vinyl propionate. , (Meta) acrylonitrile, N-vinylpyrrolidone, (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, polar group-containing monomers such as meta (acrylamide); and the like.
These may be used alone or in combination of two or more.

The content of the (meth) acrylic acid ester in the vinyl compound is preferably 40 to 100% by mass, more preferably 65 to 100% by mass, still more preferably, based on the total amount (100% by mass) of the vinyl compound. It is 80 to 100% by mass, more preferably 90 to 100% by mass.
The total content of the alkyl (meth) acrylate and the hydroxyalkyl (meth) acrylate in the vinyl compound is preferably 40 to 100% by mass, more preferably 65 to 100% by mass, based on the total amount (100% by mass) of the vinyl compound. It is 100% by mass, more preferably 80 to 100% by mass, and even more preferably 90 to 100% by mass.

The acrylic urethane resin (U1) used in the present embodiment is obtained by mixing a urethane prepolymer (UP) and a vinyl compound containing a (meth) acrylic acid ester and polymerizing both.
In the polymerization, it is preferable to further add a radical initiator.

In the acrylic urethane resin (U1) used in the present embodiment, the content ratio of the structural unit (u11) derived from the urethane prepolymer (UP) and the structural unit (u12) derived from the vinyl compound [(u11) / (U12)] is preferably 10/90 to 80/20, more preferably 20/80 to 70/30, still more preferably 30/70 to 60/40, and even more preferably 35/65 in terms of mass ratio. ~ 55/45.

[Olefin resin]
The olefin-based resin suitable as the resin contained in the resin composition (y1) is a polymer having at least a structural unit derived from an olefin monomer.
The olefin monomer is preferably an α-olefin having 2 to 8 carbon atoms, and specific examples thereof include ethylene, propylene, butylene, isobutylene, and 1-hexene.
Among these, ethylene and propylene are preferable.

Specific olefinic resins, for example, ultra low density polyethylene (VLDPE, density: 880 kg / ^{m 3} or more 910 kg / ^m less than ^3), low density polyethylene (LDPE, density: 910 kg / ^{m 3} or more 915 kg / ^m less than ³ ), Medium density polyethylene (MDPE, density: 915 kg / m ³ or more and less than 942 kg / m ³ ), high density polyethylene (HDPE, density: 942 kg / m ³ or more), linear low density polyethylene and other polyethylene resins; polypropylene resin (PP); Polybutene resin (PB); Ethylene-propylene copolymer; Olefin-based elastomer (TPO); Poly (4-methyl-1-pentene) (PMP); Ethylene-vinyl acetate copolymer (EVA); Ethylene -Vinyl alcohol copolymer (EVOH); olefin-based ternary copolymer such as ethylene-propylene- (5-ethylidene-2-norbornene); and the like.

In the present embodiment, the olefin resin may be a modified olefin resin further subjected to one or more modifications selected from acid modification, hydroxyl group modification, and acrylic modification.

For example, the acid-modified olefin-based resin obtained by acid-modifying an olefin-based resin is a modified polymer obtained by graft-polymerizing an unsaturated carboxylic acid or an anhydride thereof with the above-mentioned non-modified olefin-based resin. Can be mentioned.
Examples of the unsaturated carboxylic acid or its anhydride include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, aconitic acid, (meth) acrylic acid, maleic anhydride, and itaconic anhydride. , Glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornendicarboxylic acid anhydride, tetrahydrophthalic anhydride and the like.
The unsaturated carboxylic acid or its anhydride may be used alone or in combination of two or more.

The acrylic-modified olefin-based resin obtained by subjecting the olefin-based resin to acrylic modification is a modification obtained by graft-polymerizing an alkyl (meth) acrylate as a side chain to the above-mentioned non-modified olefin-based resin which is the main chain. Polymers can be mentioned.
The alkyl group of the above alkyl (meth) acrylate has preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and further preferably 1 to 12 carbon atoms.
Examples of the above-mentioned alkyl (meth) acrylate include the same compounds as those that can be selected as the monomer (a1') described later.

Examples of the hydroxyl group-modified olefin resin obtained by subjecting the olefin resin to hydroxyl group modification include a modified polymer obtained by graft-polymerizing a hydroxyl group-containing compound on the above-mentioned non-modified olefin resin which is the main chain.
Examples of the above-mentioned hydroxyl group-containing compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl. Hydroxyalkyl (meth) acrylates such as (meth) acrylate and 4-hydroxybutyl (meth) acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol can be mentioned.

[Resin other than acrylic urethane resin and olefin resin]
In the present embodiment, the resin composition (y1) may contain a resin other than the acrylic urethane resin and the olefin resin as long as the effects of the present invention are not impaired.
Examples of such resins include vinyl resins such as polyvinyl chloride, polyvinylidene chloride, and polyvinyl alcohol; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polystyrene; acrylonitrile-butadiene-styrene co-weight. Combined; cellulose triacetate; polycarbonate; polyurethane not applicable to acrylic urethane resin; polysulfone; polyether ether ketone; polyether sulfone; polyphenylene sulfide; polyimide resin such as polyetherimide and polyimide; polyamide resin; acrylic resin; Fluorine-based resin and the like can be mentioned.
The content ratio of the resin other than the acrylic urethane resin and the olefin resin is preferably less than 30 parts by mass, more preferably 20 parts by mass with respect to 100 parts by mass of the total amount of the resin contained in the resin composition (y1). Less than, more preferably less than 10 parts by mass, still more preferably less than 5 parts by mass, still more preferably less than 1 part by mass.

[Additives for base material]
The resin composition (y1) may contain an additive for a base material contained in a base material of a general pressure-sensitive adhesive sheet as long as the effects of the present invention are not impaired.
Examples of such base material additives include ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, slip agents, antiblocking agents, colorants and the like.
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 parts by mass with respect to 100 parts by mass of the resin in the resin composition (y1). , More preferably 0.001 to 10 parts by mass.

[Solvent-free resin composition (y1')]
As one aspect of the resin composition (y1) used in the present embodiment, an oligomer having an ethylenically unsaturated group having a mass average molecular weight (Mw) of 50,000 or less, an energy ray-polymerizable monomer, and the above-mentioned expandable particles are blended. Therefore, a solvent-free resin composition (y1') that does not contain a solvent can be mentioned.
In the solvent-free resin composition (y1'), no solvent is blended, but the energy ray-polymerizable monomer contributes to the improvement of the plasticity of the oligomer.
The base material (Y1) can be obtained by irradiating the coating film formed from the solvent-free resin composition (y1') with energy rays.
The types, shapes, and blending amounts (contents) of the expandable particles blended in the solvent-free resin composition (y1') are as described above.

The mass average molecular weight (Mw) of the oligomer contained in the solvent-free resin composition (y1') is 50,000 or less, preferably 1000 to 50,000, more preferably 2000 to 40,000, still more preferably 3000 to 35,000. Even more preferably, it is 4000 to 30000.

The oligomer may be any resin contained in the above-mentioned resin composition (y1) having an ethylenically unsaturated group having a mass average molecular weight (Mw) of 50,000 or less. Polymer (UP) is preferred.
As the oligomer, a modified olefin resin having an ethylenically unsaturated group or the like can also be used.

The total content of the oligomer and the energy ray-polymerizable monomer in the solvent-free resin composition (y1') is preferably relative to the total amount (100% by mass) of the solvent-free resin composition (y1'). Is 50 to 99% by mass, more preferably 60 to 95% by mass, still more preferably 65 to 90% by mass, and even more preferably 70 to 85% by mass.

Examples of the energy ray-polymerizable monomer include isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxy (meth) acrylate, cyclohexyl (meth) acrylate, and adamantan (). Alicyclic polymerizable compounds such as meta) acrylates and tricyclodecane acrylates; aromatic polymerizable compounds such as phenylhydroxypropyl acrylates, benzyl acrylates and phenolethylene oxide modified acrylates; tetrahydrofurfuryl (meth) acrylates, morpholine acrylates, N- Examples thereof include heterocyclic polymerizable compounds such as vinylpyrrolidone and N-vinylcaprolactam.
These energy ray-polymerizable monomers may be used alone or in combination of two or more.

The content ratio (the oligomer / energy ray-polymerizable monomer) of the oligomer to the energy ray-polymerizable monomer in the solvent-free resin composition (y1') is a mass ratio, preferably 20/80 to 90. It is / 10, more preferably 30/70 to 85/15, and even more preferably 35/65 to 80/20.

In the present embodiment, the solvent-free resin composition (y1') is preferably further blended with a photopolymerization initiator.
By containing the photopolymerization initiator, the curing reaction can be sufficiently advanced even by irradiation with relatively low energy energy rays.

Examples of the photopolymerization initiator include 1-hydroxy-cyclohexyl-phenyl-ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzylphenyl sulfide, tetramethylthium monosulfide, and azobisisobutyrol. Examples thereof include nitrile, dibenzyl, diacetyl, 8-chloranthraquinone and the like.
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 parts by mass, more preferably 0.01 to 4 parts by mass, and further, based on the total amount (100 parts by mass) of the oligomer and the energy ray-polymerizable monomer. It is preferably 0.02 to 3 parts by mass.

From the viewpoint of improving the interlayer adhesion between the base material (Y1) and other layers to be laminated, the surface of the base material (Y1) may be subjected to surface treatment or primer treatment by an oxidation method, an unevenness method, or the like. Good. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet), hot air treatment, ozone, ultraviolet irradiation treatment and the like, and examples of the unevenness method include sandblasting method and solvent treatment method. Can be mentioned.

[Storage modulus of substrate (Y1)]
The storage elastic modulus E'(23) of the base material (Y1) at 23 ° C. is preferably 1.0 × 10 ⁶ Pa or more, more preferably 5.0 × 10 ^{6 to} 5.0 × 10 ¹² Pa, still more preferably. Is 1.0 × 10 ^{7 to} 1.0 × 10 ¹² Pa, more preferably 5.0 × 10 ^{7 to} 1.0 × 10 ¹¹ Pa, and even more preferably 1.0 × 10 ^{8 to} 1.0 ×. It is 10 ¹⁰ Pa. By using the base material (Y1) having a storage elastic modulus E'(23) within the above range, it is possible to prevent the chip from being displaced and to prevent the chip from sinking into the adhesive layer (X1). You can also do it.
In the present specification, the storage elastic modulus E'of the base material (Y1) at a predetermined temperature means a value measured by the method described in the examples.

Further, it is preferable that the storage elastic modulus of the base material (Y1) satisfies the following requirement (1).
- Requirement (1): at 100 ° C., the storage modulus E of the substrate (Y1) '(100) is 2.0 × ¹⁰ 5 Pa or more.
When the chip is sealed on the pressure-sensitive adhesive sheet (A) by having the base material (Y1) satisfying the requirement (1), the expandable particles can be used even in the temperature environment of the sealing step in the manufacturing process of FOWLP and FOPLP. Since the flow can be moderately suppressed, the adhesive surface of the pressure-sensitive adhesive layer (X1) provided on the base material (Y1) is less likely to be deformed. As a result, it is possible to prevent the chip from being displaced and also to prevent the chip from sinking into the pressure-sensitive adhesive layer (X1).

From the above viewpoint, the storage elastic modulus E'(100) of the base material (Y1) is more preferably 4.0 × 10 ⁵ Pa or more, further preferably 6.0 × 10 ⁵ Pa or more, still more preferably 8. It is 0 × 10 ⁵ Pa or more, more preferably 1.0 × 10 ⁶ Pa or more.
Further, from the viewpoint of effectively suppressing the misalignment of the chips in the sealing step, the storage elastic modulus E'(100) of the base material (Y1) is preferably 1.0 × 10 ¹² Pa or less, more preferably. It is 1.0 × 10 ¹¹ Pa or less, more preferably 1.0 × 10 ¹⁰ Pa or less, and even more preferably 1.0 × 10 ⁹ Pa or less.

Further, when the base material (Y1) contained in the pressure-sensitive adhesive sheet of the present embodiment contains thermally expandable particles as expandable particles, it is preferable that the storage elastic modulus satisfies the following requirement (2).
· Requirement (2): in the expansion starting temperature (t) of the heat expandable particles, the base material (Y1) storage modulus E of the '(t), is 1.0 × ¹⁰ 7 Pa or less.
By having the base material (Y1) satisfying the requirement (2), the base material (Y1) is easily deformed according to the volume expansion of the heat-expandable particles at the temperature at which the heat-expandable particles are expanded, and the adhesive material. It becomes easy to form irregularities on the adhesive surface of the layer (X1). As a result, it can be separated from the object by a small external force.

From the above viewpoint, the storage elastic modulus E'(t) of the base material (Y1) is more preferably 9.0 × 10 ⁶ Pa or less, still more preferably 8.0 × 10 ⁶ Pa or less, still more preferably 6. It is 0 × 10 ⁶ Pa or less, more preferably 4.0 × 10 ⁶ Pa or less.
Further, from the viewpoint of suppressing the flow of expanded heat-expandable particles, improving the shape-retaining property of the unevenness formed on the adhesive surface of the pressure-sensitive adhesive layer (X1), and further improving the separability, the base material (Y1) The storage elastic modulus E'(t) of is preferably 1.0 × 10 ³ Pa or more, more preferably 1.0 × 10 ⁴ Pa or more, and further preferably 1.0 × 10 ⁵ Pa or more.

(Non-expandable base material (Y1'))
The pressure-sensitive adhesive sheet (A) may have a pressure-sensitive adhesive layer (X1) on one surface of the base material (Y1) and a non-expandable base material (Y1') on the other side.
The "non-expandable substrate" in the present specification means that the volume change rate calculated from the following formula is less than 5% by volume when treated under the condition that the expandable particles contained in the pressure-sensitive adhesive sheet (A) expand. Defined as a thing.
Volume change rate (%) = (volume of the layer after treatment-volume of the layer before treatment) / volume of the layer before treatment × 100
The volume change rate (%) of the non-expandable base material (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. More preferably, it is less than 0.01% by volume.
When the expandable particles are thermally expandable particles, the condition for the expandable particles to expand is a condition in which heat treatment is performed for 3 minutes at the expansion start temperature (t).
The non-expandable base material (Y1') may contain expandable particles, but the smaller the content, the more preferable, and the total mass (100% by mass) of the non-expandable base material (Y1') is preferable. Usually, it is less than 3% by mass, preferably less than 1% by mass, more preferably less than 0.1% by mass, still more preferably less than 0.01% by mass, still more preferably less than 0.001% by mass, and expand. Most preferably, it does not contain sex particles.

Examples of the material for forming the non-expandable base material (Y1') include paper materials, resins, metals and the like.
Examples of the paper material include thin leaf paper, medium-quality paper, high-quality paper, impregnated paper, coated paper, art paper, parchment paper, and glassin paper.
Examples of the resin include polyolefin resins such as polyethylene and polypropylene; vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer; polyethylene terephthalate and poly. Polyimide-based resins such as butylene terephthalate and polyethylene naphthalate; polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; urethane resins such as polyurethane and acrylic-modified polyurethane; polymethylpentene; polysulfone; polyether ether ketone; Polyether sulfone; polyphenylene sulfide; polyimide resin such as polyetherimide and polyimide; polyamide resin; acrylic resin; fluorine resin and the like can be mentioned.
Examples of the metal include aluminum, tin, chromium, titanium and the like.
These forming materials may be composed of one kind, or two or more kinds may be used in combination.
As the non-expandable base material (Y1') in which two or more kinds of forming materials are used in combination, a paper material laminated with a thermoplastic resin such as polyethylene, a resin film containing the resin, or a metal film formed on the surface of the sheet. Things etc. can be mentioned.
As a method for forming the metal layer, for example, a method of vapor-depositing the metal by a PVD method such as vacuum vapor deposition, sputtering, or ion plating, or a method of attaching a metal foil made of the metal by using a general adhesive. The method of doing this can be mentioned.

When the pressure-sensitive adhesive sheet (A) has a non-expandable base material (Y1'), the thickness of the expandable base material (Y1) and the non-expandable base material (Y1') before expanding the expandable particles. The ratio [(Y1) / (Y1')] is preferably 0.02 to 200, more preferably 0.03 to 150, and even more preferably 0.05 to 100.

When the non-expandable base material (Y1') contains a resin, the non-expandable base material (Y1') is used from the viewpoint of improving the interlayer adhesion between the non-expandable base material (Y1') and other layers to be laminated. The surface of the above-mentioned base material (Y1) may also be subjected to surface treatment or primer treatment by an oxidation method, an unevenness method or the like.
When the non-expandable base material (Y1') contains a resin, the above-mentioned base material additive which can be contained in the resin composition (y1) may be contained together with the resin.

(Adhesive layer (X1))
The pressure-sensitive adhesive layer (X1) is a layer having adhesiveness. The pressure-sensitive adhesive layer (X1) contains a pressure-sensitive adhesive resin, and may contain a pressure-sensitive adhesive additive such as a cross-linking agent, a pressure-sensitive adhesive, a polymerizable compound, and a polymerization initiator, if necessary.

The adhesive strength of the adhesive surface of the pressure-sensitive adhesive layer (X1) is preferably 0.1 to 10.0 N / 25 mm, more preferably 0.2 to 8.0 N / 25 mm at 23 ° C. before the expandable particles expand. , More preferably 0.4 to 6.0 N / 25 mm, and even more preferably 0.5 to 4.0 N / 25 mm. When the adhesive strength is 0.1 N / 25 mm or more, it can be firmly adhered to the chip on the expanding tape, so that the expanding tape and the chip can be easily separated. On the other hand, if the adhesive strength is 10.0 N / 25 mm or less, the chip can be easily separated with a slight force.
The above-mentioned adhesive strength means a value measured by the method described in Examples.

The storage shear modulus G'(23) of the pressure-sensitive adhesive layer (X1) is preferably 1.0 × 10 ^{4 to} 1.0 × 10 ⁸ Pa, more preferably 5.0 × 10 ^{4 to} 5 at 23 ° C. It is 0.0 × 10 ⁷ Pa, more preferably 1.0 × 10 ^{5 to} 1.0 × 10 ⁷ Pa. When the storage shear elastic modulus G'(23) of the pressure-sensitive adhesive layer (X1) is 1.0 × 10 ⁴ Pa or more, the misalignment of the chips can be prevented. On the other hand, if the storage shear modulus G '(23) is less than 1.0 × 10 8 ^Pa pressure-sensitive adhesive layer (X1), easily irregularities by expanded expandable particles are formed on the adhesive surface with little force It can be easily separated.
When the pressure-sensitive adhesive sheet (A) is a pressure-sensitive adhesive sheet having a plurality of pressure-sensitive adhesive layers, the storage shear elastic modulus G'(23) of the pressure-sensitive adhesive layer to which the chips are attached is preferably within the above range, and the base material ( It is preferable that the storage shear elastic modulus G'(23) of all the pressure-sensitive adhesive layers on the side to which the chip is attached is within the above range than Y1).
In addition, in this specification, the storage shear elastic modulus G'(23) of the pressure-sensitive adhesive layer (X1) means the value measured by the method described in Example.

The thickness of the pressure-sensitive adhesive layer (X1) forms irregularities on the surface of the pressure-sensitive adhesive layer formed by the viewpoint of exhibiting excellent adhesive strength and the expansion of expandable particles in the expandable base material by heat treatment. From the viewpoint of facilitation, it is preferably 1 to 60 μm, more preferably 2 to 50 μm, still more preferably 3 to 40 μm, still more preferably 5 to 30 μm.

The ratio of the thickness of the base material (Y1) to the thickness of the pressure-sensitive adhesive layer (X1) (base material (Y1) / pressure-sensitive adhesive layer (X1)) is set at 23 ° C. from the viewpoint of preventing the misalignment of the chips. It is preferably 0.2 or more, more preferably 0.5 or more, still more preferably 1.0 or more, still more preferably 5.0 or more, and can be easily separated with a slight force when separated. From the viewpoint of forming an adhesive sheet, it is preferably 1000 or less, more preferably 200 or less, still more preferably 60 or less, still more preferably 30 or less.
The thickness of the pressure-sensitive adhesive layer (X1) means a value measured by the method described in Examples.

The pressure-sensitive adhesive layer (X1) can be formed from the pressure-sensitive adhesive composition (x1) containing a pressure-sensitive adhesive resin. Hereinafter, each component contained in the pressure-sensitive adhesive composition (x1) will be described.

[Adhesive resin]
The adhesive resin that is the material for forming the pressure-sensitive adhesive layer (X1) is preferably a polymer that has adhesiveness by itself and has a mass average molecular weight (Mw) of 10,000 or more. The mass average molecular weight (Mw) of the adhesive resin is more preferably 10,000 to 2 million, still more preferably 20,000 to 1.5 million, and even more preferably 30,000 to 1,000,000 from the viewpoint of improving the adhesive strength.

Examples of the adhesive resin include rubber-based resins such as acrylic resins, urethane-based resins, and polyisobutylene-based resins, polyester-based resins, olefin-based resins, silicone-based resins, and polyvinyl ether-based resins.
These adhesive resins may be used alone or in combination of two or more.
When these adhesive resins are copolymers having two or more kinds of structural units, the form of the copolymer is not particularly limited, and block copolymers, random copolymers, and graft copolymers are used. It may be any of the polymers.

The adhesive resin may be an energy ray-curable adhesive resin in which a polymerizable functional group is introduced into the side chain of the adhesive resin.
Examples of the polymerizable functional group include a (meth) acryloyl group and a vinyl group.
Examples of the energy ray include ultraviolet rays and electron beams, but ultraviolet rays are preferable.

The content of the adhesive resin is preferably 30 to 99.99% by mass, more preferably 40 to 99.95% by mass, based on the total amount (100% by mass) of the active ingredient of the pressure-sensitive adhesive composition (x1). It is still more preferably 50 to 99.90% by mass, even more preferably 55 to 99.80% by mass, and even more preferably 60 to 99.50% by mass.
In the following description of the present specification, "the content of each component with respect to the total amount of the active ingredient of the pressure-sensitive adhesive composition" is "the content of each component in the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition". Is synonymous with.

The adhesive resin is acrylic-based from the viewpoint of exhibiting excellent adhesive strength and making it easy to form irregularities on the adhesive surface due to expansion of expansive particles to improve separability when separated. It preferably contains a resin.
The content ratio of the acrylic resin in the adhesive resin is preferably 30 to 100% by mass, more preferably 50, based on the total amount (100% by mass) of the adhesive resin contained in the pressure-sensitive adhesive composition (x1). It is ~ 100% by mass, more preferably 70 to 100% by mass, and even more preferably 85 to 100% by mass.

[Acrylic resin]
Acrylic resins that can be used as adhesive resins include, for example, polymers containing structural units derived from alkyl (meth) acrylates having linear or branched alkyl groups, and (meth) acrylates having a cyclic structure. Examples include polymers containing the derived structural unit, and the structural unit (a1) and the functional group-containing monomer (a2) derived from the alkyl (meth) acrylate (a1') (hereinafter, also referred to as “monomer (a1')”). An acrylic copolymer (A1) having a structural unit (a2) derived from') (hereinafter, also referred to as "monomer (a2')") is more preferable.

The number of carbon atoms of the alkyl group contained in the monomer (a1') is preferably 1 to 24, more preferably 1 to 12, still more preferably 2 to 10, and even more preferably 4 to 8 from the viewpoint of improving adhesive properties. Is.
The alkyl group contained in the monomer (a1') may be a straight chain alkyl group or a branched chain alkyl group.
Examples of the monomer (a1') include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and tridecyl (). Examples thereof include meta) acrylate and stearyl (meth) acrylate.
These monomers (a1') may be used alone or in combination of two or more.
As the monomer (a1'), butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferable.
The content of the structural unit (a1) is preferably 50 to 99.9% by mass, more preferably 60 to 99.0% by mass, based on the total structural unit (100% by mass) of the acrylic copolymer (A1). %, More preferably 70 to 97.0% by mass, still more preferably 80 to 95.0% by mass.

Examples of the functional group contained in the monomer (a2') include a hydroxyl group, a carboxy group, an amino group, an epoxy group and the like.
That is, examples of the monomer (a2') include a hydroxyl group-containing monomer, a carboxy 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, as the monomer (a2'), a hydroxyl group-containing monomer and a carboxy group-containing monomer are preferable.
Examples of the hydroxyl group-containing monomer include the same hydroxyl group-containing compounds as described above.
Examples of the carboxy group-containing monomer 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, and their anhydrides. , 2- (Acryloyloxy) ethyl succinate, 2-carboxyethyl (meth) acrylate and the like.
The content of the structural unit (a2) is preferably 0.1 to 40% by mass, more preferably 0.5 to 35% by mass, based on the total structural unit (100% by mass) of the acrylic copolymer (A1). %, More preferably 1.0 to 30% by mass, and even more preferably 3.0 to 25% by mass.

The acrylic copolymer (A1) may further have a structural unit (a3) derived from a monomer (a3') other than the monomers (a1') and (a2').
In the acrylic copolymer (A1), the content of the structural units (a1) and (a2) is preferably 70 with respect to the total structural units (100% by mass) of the acrylic copolymer (A1). It is -100% by mass, more preferably 80 to 100% by mass, still 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 isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; diene monomers such as butadiene, isoprene and chloroprene; cyclohexyl (meth) acrylates, It has a cyclic structure such as benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and imide (meth) acrylate. (Meta) Acrylate; Examples thereof include styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, (meth) acrylamide, (meth) acrylonitrile, (meth) acryloylmorpholine, and N-vinylpyrrolidone.

The acrylic copolymer (A1) may be an energy ray-curable acrylic copolymer in which a polymerizable functional group is introduced into the side chain. The polymerizable functional group and the energy ray are as described above. The polymerizable functional group is a substituent capable of binding to an acrylic copolymer having the above-mentioned structural units (a1) and (a2) and a functional group having the structural unit (a2) of the acrylic copolymer. It can be introduced by reacting with a compound having a polymerizable functional group.
Examples of the compound include (meth) acryloyloxyethyl isocyanate, (meth) acryloyl isocyanate, and glycidyl (meth) acrylate.

The mass average molecular weight (Mw) of the acrylic resin is preferably 100,000 to 1,500,000, more preferably 200,000 to 1,300,000, still more preferably 350,000 to 1,200,000, and even more preferably 500,000 to 1,100,000.

[Crosslinking agent]
When the pressure-sensitive adhesive composition (x1) contains a pressure-sensitive adhesive resin containing a functional group such as the above-mentioned acrylic copolymer (A1), it is preferable that the pressure-sensitive adhesive composition (x1) further contains a cross-linking agent.
The cross-linking agent reacts with a tacky resin having a functional group and cross-links the tacky resins with the functional group as a cross-linking starting point.
Examples of the cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, and metal chelate-based cross-linking agents.
These cross-linking agents may be used alone or in combination of two or more.
Among these cross-linking agents, isocyanate-based cross-linking agents are preferable from the viewpoint of increasing the cohesive force to improve the adhesive force and the availability.
The content of the cross-linking agent is appropriately adjusted according to the number of functional groups of the adhesive resin, and is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the adhesive resin having functional groups. It is more preferably 0.03 to 7 parts by mass, and further preferably 0.05 to 5 parts by mass.

[Adhesive imparting agent]
The pressure-sensitive adhesive composition (x1) may further contain a pressure-sensitive adhesive from the viewpoint of further improving the adhesive strength.
In the present specification, the "tackiness-imparting agent" refers to an oligomer having a mass average molecular weight (Mw) of less than 10,000, which is a component that supplementarily improves the adhesive strength of the above-mentioned adhesive resin, and refers to the above-mentioned adhesion. It is distinguished from the sex resin.
The mass average molecular weight (Mw) of the tackifier is preferably 400 to 10000, more preferably 500 to 8000, and even more preferably 800 to 5000.

As the tackifier, for example, it is obtained by copolymerizing a C5 distillate such as rosin resin, terpene resin, styrene resin, penten, isoprene, piperin, 1,3-pentadiene produced by thermal decomposition of petroleum naphtha. Examples thereof include C5-based petroleum resins, C9-based petroleum resins obtained by copolymerizing C9 distillates such as inden and vinyl toluene produced by thermal decomposition of petroleum naphtha, and hydrides obtained by hydrogenating these.

The softening point of the tackifier is preferably 60 to 170 ° C, more preferably 65 to 160 ° C, and even more preferably 70 to 150 ° C.
In the present specification, the "softening point" of the tackifier means a value measured in accordance with JIS K 2531.
The tackifier may be used alone, or two or more kinds having different softening points, structures, etc. may be used in combination. When two or more kinds of tackifiers are used, it is preferable that the weighted average of the softening points of the plurality of tackifiers belongs to the above range.

The content of the tackifier is preferably 0.01 to 65% by mass, more preferably 0.05 to 55% by mass, based on the total amount (100% by mass) of the active ingredient of the pressure-sensitive adhesive composition (x1). It is still more preferably 0.1 to 50% by mass, even more preferably 0.5 to 45% by mass, and even more preferably 1.0 to 40% by mass.

[Photopolymerization initiator]
In the present embodiment, when the pressure-sensitive adhesive composition (x1) contains an energy ray-curable pressure-sensitive adhesive resin as the pressure-sensitive adhesive resin, it is preferable that the pressure-sensitive adhesive composition (x1) further contains a photopolymerization initiator.
By preparing a pressure-sensitive adhesive composition containing an energy ray-curable pressure-sensitive adhesive resin and a photopolymerization initiator, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be subjected to irradiation with relatively low-energy energy rays. The curing reaction can be sufficiently advanced, and the adhesive strength can be adjusted to a desired range.
Examples of the photopolymerization initiator include the same ones that are blended in the solvent-free resin composition (y1) described above.
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 even more preferably 0, with respect to 100 parts by mass of the energy ray-curable adhesive resin. It is 05 to 2 parts by mass.

[Additives for adhesives]
In the present embodiment, the pressure-sensitive adhesive composition (x1), which is a material for forming the pressure-sensitive adhesive layer (X1), is used for general pressure-sensitive adhesives in addition to the above-mentioned additives as long as the effects of the present invention are not impaired. It may contain an additive for a pressure-sensitive adhesive.
Examples of such additives for adhesives include antioxidants, softeners (plasticizers), rust inhibitors, pigments, dyes, retarders, reaction accelerators (catalysts), ultraviolet absorbers and the like.
These adhesive additives may be used alone or in combination of two or more.
When these additives for adhesives are contained, the content of each additive for adhesives is preferably 0.0001 to 20 parts by mass, more preferably 0.001 with respect to 100 parts by mass of the adhesive resin. It is 10 parts by mass.
The pressure-sensitive adhesive layer (X1) may contain expansive particles. The content thereof is preferably 5 parts by mass or less, more preferably 2 parts by mass or less, and most preferably not contained with respect to 100 parts by mass of the adhesive resin.

(Release material)
Examples of the release material arbitrarily used include a release sheet subjected to double-sided release treatment, a release sheet subjected to single-sided release treatment, and a material obtained by applying a release agent on a base material for the release material.
Examples of the base material for the release material include papers such as high-quality paper, glassin paper, and kraft paper; polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin, polypropylene resin, and polyethylene resin. Plastic films such as olefin resin films; and the like.
Examples of the release agent include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins.
The thickness of the release material is not particularly limited, but is preferably 10 to 200 μm, more preferably 25 to 170 μm, and even more preferably 35 to 80 μm.

<Manufacturing method of adhesive sheet (A)>
The method for producing the pressure-sensitive adhesive sheet (A) is not particularly limited, and examples thereof include a production method (I) having the following steps (Ia) and (Ib).
Step (Ia): A resin composition (y1), which is a material for forming a base material (Y1), is applied onto the peeling surface of the release material to form a coating film, and the coating film is dried or UV-cured. A step of forming a base material (Y1).
Step (Ib): A pressure-sensitive adhesive composition (x1), which is a material for forming the pressure-sensitive adhesive layer (X1), is applied onto the surface of the formed base material (Y1) to form a coating film, and the coating film is dried. The step of forming the pressure-sensitive adhesive layer (X1).

As another manufacturing method of the pressure-sensitive adhesive sheet (A), for example, a manufacturing method (II) having the following steps (IIa) to (IIc) can be mentioned.
Step (IIa): A resin composition (y1), which is a material for forming a base material (Y1), is applied onto the peeling surface of the release material to form a coating film, and the coating film is dried or UV-cured. A step of forming a base material (Y1).
Step (IIb): A pressure-sensitive adhesive composition (x1), which is a material for forming the pressure-sensitive adhesive layer (X1), is applied onto the peel-processed surface of the release material to form a coating film, and the coating film is dried and adhered. The process of forming the agent layer.
Step (IIc): A step of bonding the surface of the base material (Y1) formed in the step (IIa) and the surface of the pressure-sensitive adhesive layer (X1) formed in the step (IIb).

In the above-mentioned production methods (I) and (II), the resin composition (y1) and the pressure-sensitive adhesive composition (x1) may be in the form of a solution by blending a diluting solvent.
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.

It is preferable that the drying or UV irradiation in the production method (I) and the production method (II) is carried out by appropriately selecting the conditions under which the expanding particles do not expand. For example, when the resin composition (y1) containing the heat-expandable particles is dried to form the base material (Y1), the drying temperature is preferably lower than the expansion start temperature (t) of the heat-expandable particles. ..
When the pressure-sensitive adhesive sheet (A) has a base material (Y1) and a non-expandable base material (Y1'), the resin composition (y1) is previously prepared in the steps (Ia) and (IIa). It may be applied on the formed non-expandable base material (Y1'). The non-expandable base material (Y1') is formed by, for example, using a resin composition which is a material for forming the non-expandable base material (Y1') by the same operation as in steps (Ia) and (IIa). be able to.

[Each manufacturing process of the semiconductor device according to this embodiment]
Next, each step of the method for manufacturing a semiconductor device according to the present embodiment will be described.
The method for manufacturing a semiconductor device according to the present embodiment includes the following steps (1) to (3) in this order.
Step (1): The distance between a plurality of chips placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2) is set by the pressure-sensitive adhesive sheet (B). The process of stretching and spreading.
Step (2): A step of attaching the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) to the surface of the plurality of chips opposite to the surface in contact with the pressure-sensitive adhesive layers (X2).
Step (3): A step of separating the plurality of chips attached to the adhesive sheet (A) from the adhesive sheet (B).
Hereinafter, an example in which a semiconductor chip is used as the chip will be described with reference to the drawings.

<Process (1)>
In the step (1), the distance between the plurality of semiconductor chips placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2) is set by the pressure-sensitive adhesive sheet (1). B) is a process of stretching and expanding. Before the step (1), a dicing step and a semiconductor chip reversing step described later may be performed.

(Adhesive sheet (B))
The adhesive sheet (B) is used as an expanding tape that widens the distance between the semiconductor chip CPs.
Specifically, the pressure-sensitive adhesive sheet (B) has a base material (Y2) and a pressure-sensitive adhesive layer (X2), and the distance between a plurality of semiconductor chip CPs placed on the pressure-sensitive adhesive layer (X2) is set. It is used to stretch and spread the adhesive sheet (B).

Examples of the material of the base material (Y2) include polyvinyl chloride resin, polyester resin (polyethylene terephthalate, etc.), acrylic resin, polycarbonate resin, polyethylene resin, polypropylene resin, acrylonitrile, butadiene, styrene resin, polyimide resin, and polyurethane resin. And polystyrene resin and the like.
The base material (Y2) preferably contains a thermoplastic elastomer, a rubber-based material, or the like, and more preferably contains a thermoplastic elastomer.
Examples of the thermoplastic elastomer include urethane-based elastomers, olefin-based elastomers, vinyl chloride-based elastomers, polyester-based elastomers, styrene-based elastomers, acrylic-based elastomers, and amide-based elastomers.

The base material (Y2) may be a film obtained by laminating a plurality of layers of the film made of the above material, or may be a film obtained by laminating a film made of the above material and another film.
The base material (Y2) may contain various additives such as pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, fillers, etc. in the film mainly made of the above resin-based material. ..

The pressure-sensitive adhesive layer (X2) may be composed of a non-energy ray-curable pressure-sensitive adhesive or an energy ray-curable pressure-sensitive adhesive.
The non-energy ray-curable pressure-sensitive adhesive preferably has desired adhesive strength and removability. For example, acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive, silicone-based pressure-sensitive adhesive, urethane-based pressure-sensitive adhesive, and polyester-based pressure-sensitive adhesive. , Polyvinyl ether adhesive and the like. Among these, an acrylic pressure-sensitive adhesive is preferable from the viewpoint of effectively suppressing the semiconductor chips and the like from falling off when the pressure-sensitive adhesive sheet (B) is stretched.

Since the energy ray-curable pressure-sensitive adhesive is cured by energy ray irradiation and its adhesive strength is lowered, it can be easily separated by irradiating the energy ray when separating the semiconductor chip and the pressure-sensitive adhesive sheet (B). ..
Examples of the energy ray-curable pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer (X2) include (a) a polymer having energy ray-curability, and (b) a monomer having at least one energy ray-curable group and /. Alternatively, those containing one or more selected from oligomers can be mentioned.
(A) As the polymer having energy ray curability, a (meth) acrylic acid ester (co) weight in which a functional group (energy ray curable group) having energy ray curability such as an unsaturated group is introduced into the side chain. Coalescence is preferred. Examples of the acrylic acid ester (co) polymer include an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms, a polymerizable double bond, a hydroxy group, a carboxy group, an amino group, and a substituent. Examples thereof are those obtained by copolymerizing with a monomer having a functional group such as an amino group or an epoxy group in the molecule, and then further reacting with an unsaturated group-containing compound having a functional group bonded to the functional group. Be done.
(B) Examples of the monomer and / or oligomer having at least one or more energy ray-curable groups include esters of polyhydric alcohol and (meth) acrylic acid, and specifically, cyclohexyl (meth) acrylate. Monofunctional acrylic acid esters such as isobornyl (meth) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1 , 4-Butandiol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dimethylol tricyclodecanedi (meth) acrylate and other polyfunctional acrylic acid esters. , Polyester oligo (meth) acrylate, polyurethane oligo (meth) acrylate and the like.
In the energy ray-curable pressure-sensitive adhesive, in addition to the above components, a photopolymerization initiator, a cross-linking agent and the like may be appropriately added.

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

The breaking elongation of the pressure-sensitive adhesive sheet (B) measured in the MD direction and the CD direction at 23 ° C. is preferably 100% or more, respectively. When the elongation at break is within the above range, it is possible to significantly stretch. Therefore, it can be suitably used for applications such as manufacturing a fan-out type package in which semiconductor chips need to be sufficiently separated from each other.

<Dicing process, semiconductor chip inversion process and transfer process>
The method of mounting the plurality of semiconductor chip CPs on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) is not particularly limited, and examples thereof include a method of carrying out the following dicing step, inversion step, and transfer step.
Dicing step: After the semiconductor wafer W is attached to the pressure-sensitive adhesive layer (X3) of the pressure-sensitive adhesive sheet (C) including the base material (Y3) and the pressure-sensitive adhesive layer (X3), the semiconductor wafer W is diced and the pressure-sensitive adhesive layer (X3) Step of obtaining a plurality of semiconductor chip CPs separated on X3) Semiconductor chip inversion step: A plurality of semiconductor chips using an adhesive sheet (D) having a base material (Y4) and an adhesive layer (X4). The pressure-sensitive adhesive layer (X4) of the pressure-sensitive adhesive sheet (D) is attached to the surface of the CP opposite to the surface in contact with the pressure-sensitive adhesive layer (X3), and the plurality of semiconductor chip CPs and the pressure-sensitive adhesive sheet (C) are separated. Process.
Transfer step: Using the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2), the surface of the plurality of semiconductor chips CP is adhered to the surface opposite to the surface in contact with the pressure-sensitive adhesive layer (X4). A step of attaching the adhesive layer (X2) of the sheet (B) and separating the plurality of semiconductor chip CPs and the adhesive sheet (D).

(Dicing process)
In FIGS. 2A and 2B, after the semiconductor wafer W is attached to the pressure-sensitive adhesive layer (X3) of the pressure-sensitive adhesive sheet (C), the semiconductor wafer W is diced and individually placed on the pressure-sensitive adhesive layer (X3). A cross-sectional view illustrating a dicing process for obtaining a plurality of separated semiconductor chip CPs is shown.
The adhesive sheet (C) is not particularly limited as long as it can achieve the above object, but since it is necessary that the adhesive sheet (C) can be attached and separated from the semiconductor chip, expandable particles such as the adhesive sheet (A) can be used. An adhesive sheet containing an adhesive sheet, an adhesive sheet having an adhesive layer composed of a non-energy ray-curable adhesive having removability, and an adhesive layer composed of an energy ray-curable adhesive, such as an expanding tape described later. An adhesive sheet or the like to have is suitable.
When the adhesive sheet (A) is used as the adhesive sheet (C), the aspect of the adhesive sheet (A) used in the step (3) and the aspect of the adhesive sheet (A) used in this step are the same. May be different.

The semiconductor wafer W may be, for example, a silicon wafer or a compound semiconductor wafer such as gallium or arsenide.
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. In the present specification, the surface opposite to the circuit surface W1 may be referred to as "chip back surface".
The semiconductor wafer W is ground to a predetermined thickness in advance to expose the back surface of the chip and attached to the adhesive sheet (A). Examples of the method for grinding the semiconductor wafer W include a known method using a grinder or the like.
A ring frame may be attached to the pressure-sensitive adhesive sheet (C) for the purpose of holding the semiconductor wafer W. In this case, the ring frame and the semiconductor wafer W are placed on the pressure-sensitive adhesive layer (X3) of the pressure-sensitive adhesive sheet (C), and these are lightly pressed and fixed.
Next, the semiconductor wafer W held on the pressure-sensitive adhesive sheet (C) is individualized by dicing to form a plurality of semiconductor chip CPs. For dicing, for example, a cutting means such as a dicing saw, a laser, plasma dicing, or stealth dicing is used. The cutting depth at the time of dicing may be appropriately set in consideration of the thickness of the semiconductor wafer, and may be, for example, within 2 μm from the upper surface of the pressure-sensitive adhesive layer (X3).
In addition, this step may be referred to as a "first dicing step" in order to distinguish it from another dicing step described later.
The step (1) may include a process of dicing the semiconductor wafer W and then stretching the pressure-sensitive adhesive sheet (C) in order to widen the distance between the obtained plurality of semiconductor chip CPs.

(Reversal process)
In FIGS. 3A and 3B, a pressure-sensitive adhesive sheet (D) having a base material (Y4) and a pressure-sensitive adhesive layer (X4) is used, and surfaces in contact with the pressure-sensitive adhesive layers (X3) of a plurality of semiconductor chip CPs. A cross-sectional view illustrating a step of attaching the pressure-sensitive adhesive layer (X4) of the pressure-sensitive adhesive sheet (D) and separating the plurality of semiconductor chips CP and the pressure-sensitive adhesive sheet (C) is shown on the surface opposite to the surface. ..
This step is an arbitrary step carried out according to the subsequent steps, and is carried out for the purpose of inverting the front and back surfaces (that is, the circuit surface W1 and the chip back surface) of the plurality of semiconductor chip CPs.
The adhesive sheet (D) is not particularly limited as long as it can achieve the above object, but since it is necessary that the adhesive sheet (D) can be attached and separated from the semiconductor chip, expandable particles such as the adhesive sheet (A) can be used. An adhesive sheet containing, an adhesive sheet having an adhesive layer composed of a non-energy ray-curable adhesive having removability, and an adhesive layer composed of an energy ray-curable adhesive, such as an expanding tape described later. An adhesive sheet or the like to have is suitable.
The method for separating the plurality of semiconductor chip CPs and the pressure-sensitive adhesive sheet (C) may be determined according to the aspect of the pressure-sensitive adhesive sheet (C), and the pressure-sensitive adhesive layer (X3) is composed of a non-energy ray-curable pressure-sensitive adhesive. If it is, it may be peeled off again under predetermined conditions, and if the pressure-sensitive adhesive layer (X3) is composed of an energy ray-curable pressure-sensitive adhesive, it is cured by energy ray irradiation to reduce the adhesive strength. If the pressure-sensitive adhesive sheet (C) contains expandable particles such as the pressure-sensitive adhesive sheet (A), the expandable particles may be expanded to reduce the adhesive force before separation. At the time of separation, the pressure-sensitive adhesive sheet (C) is maintained so that at least the pressure-sensitive adhesive layer (X4) of the pressure-sensitive adhesive sheet (D) is more adhesive than the pressure-sensitive adhesive layer (X3) of the pressure-sensitive adhesive sheet (C). And the type of adhesive sheet (D) and the peeling method are selected.

(Transfer process)
In FIGS. 4A and 4B, a pressure-sensitive adhesive sheet (B) having a base material (Y2) and a pressure-sensitive adhesive layer (X2) is used, and surfaces in contact with the pressure-sensitive adhesive layers (X4) of a plurality of semiconductor chip CPs. A cross-sectional view illustrating a transfer process in which the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) is attached to the surface opposite to the surface and the plurality of semiconductor chips CP and the pressure-sensitive adhesive sheet (D) are separated is shown. There is.
This step is a step of transferring a plurality of semiconductor chip CPs transferred onto the pressure-sensitive adhesive sheet (D) by the inversion step to the pressure-sensitive adhesive sheet (B) which is an expanding tape. As a result, the front and back sides of the plurality of semiconductor chip CPs are opposite to those in the dicing process.
The method for separating the plurality of semiconductor chip CPs and the pressure-sensitive adhesive sheet (D) may be determined according to the mode of the pressure-sensitive adhesive sheet (D), as in the case of the pressure-sensitive adhesive sheet (C).

<Expanding process>
In FIGS. 5A and 5B, a plurality of semiconductor chip CPs placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2) are shown. A cross-sectional view illustrating a step (1) (expanding step) of stretching and expanding the adhesive sheet (B) is shown.
Through the transfer step, as shown in FIG. 5A, the plurality of semiconductor chip CPs are placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B).
Next, as shown in FIG. 5B, the adhesive sheet (B) is stretched to widen the distance between the plurality of semiconductor chip CPs to a distance D.
As a method of stretching the adhesive sheet (B), a method of pressing an annular or circular expander to stretch the adhesive sheet (B), a method of grasping and stretching the outer peripheral portion of the adhesive sheet (B) using a gripping member or the like. And so on.
The distance D between the plurality of semiconductor chip CPs after expansion may be appropriately determined according to the desired form of the semiconductor device, but is preferably 50 to 6000 μm.

<Steps (2) and (3)>
In FIGS. 6A and 6B, a plurality of semiconductor chips on the adhesive sheet (B) which is an expanding tape are used by using the adhesive sheet (A) having the base material (Y1) and the adhesive layer (X1). The step (2) of attaching the adhesive layer (X1) of the adhesive sheet (A) to the surface of the CP opposite to the surface in contact with the adhesive layer (X2), and the adhesive sheet (2) from the plurality of semiconductor chip CPs. A cross-sectional view illustrating the step (3) of separating B) is shown.
In this step, the method for separating the pressure-sensitive adhesive sheet (B) and the plurality of semiconductor chip CPs may be determined according to the aspect of the pressure-sensitive adhesive sheet (B), as in the case of the pressure-sensitive adhesive sheet (C).

Through the steps (1) to (3), as shown in FIG. 7, a plurality of semiconductor chip CPs having wide distances from each other are obtained on the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A).
The plurality of semiconductor chip CPs on the pressure-sensitive adhesive sheet (A) may then be sealed on the pressure-sensitive adhesive sheet (A) with a sealing resin and then subjected to a rewiring forming step, or separated from the pressure-sensitive adhesive sheet (A). Then, it may be subjected to the step of aligning the semiconductor chips and then subjected to the sealing step and the rewiring forming step.
In any case, the pressure-sensitive adhesive sheet (A) and the plurality of semiconductor chip CPs adhere to the pressure-sensitive adhesive layer (X1) by expanding the expandable particles with heat, energy rays, or the like according to their types. By forming irregularities on the surface (X1a), the adhesive strength between the adhesive surface (X1a) and the plurality of semiconductor chip CPs can be reduced, and the adhesive sheet (A) and the plurality of semiconductor chip CPs can be separated. ..

The method for 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, they may be heated to a temperature equal to or higher than the expansion start temperature (t). .. Here, the "expansion start temperature (t) or higher" is preferably "expansion start temperature (t) + 10 ° C." or higher and "expansion start temperature (t) + 60 ° C." or lower, and "expansion start temperature (t) + 60 ° C." More preferably, it is "t) + 15 ° C." or higher and "expansion start temperature (t) + 40 ° C." or lower. Specifically, depending on the type of the heat-expandable particles, for example, it may be heated to the range of 120 to 250 ° C. and expanded.

The expansion of the expandable particles is preferably carried out in a state where the surface (Y1a) of the base material (Y1) opposite to the pressure-sensitive adhesive layer (X1) is fixed. By fixing the surface (Y1a), the generation of unevenness on the side of the surface (Y1a) is physically suppressed, and the unevenness is efficiently formed on the adhesive surface (X1a) side of the adhesive layer (X1). be able to. Any method can be adopted for the fixing, for example, a method of providing the non-expandable base material (Y1') on the surface (Y1a) side of the base material (Y1), and a plurality of suction holes as a fixing jig. A method of fixing the surface (Y1a) of the base material (Y1) using a suction table having the above, a hard support on the surface (Y1a) of the base material (Y1) via an arbitrary adhesive layer, a double-sided adhesive sheet, or the like. There is a method of pasting.
The suction table has a decompression mechanism such as a vacuum pump, and the object is fixed to the suction surface by sucking the object from a plurality of suction holes by the decompression mechanism.
The material of the hard support may be appropriately determined in consideration of mechanical strength, heat resistance, etc. For example, a metal material such as SUS; a non-metallic inorganic material such as glass or silicon wafer; epoxy, ABS, acrylic, etc. Resin materials such as engineering plastics, super engineering plastics, polyimides and polyamideimides; composite materials such as glass epoxy resins are mentioned, and among these, SUS, glass, silicon wafers and the like are preferable. Examples of engineering plastics include nylon, polycarbonate (PC), polyethylene terephthalate (PET), and the like. Examples of super engineering plastics include polyphenylene sulfide (PPS), polyethersulfone (PES), and polyetheretherketone (PEEK).

Next, a step of sealing the plurality of semiconductor chip CPs on the pressure-sensitive adhesive sheet (A) with a sealing resin on the pressure-sensitive adhesive sheet (A) and then forming rewiring (hereinafter, also referred to as “step (4A)”). ) And the step of separating the plurality of semiconductor chip CPs from the adhesive sheet (A) and aligning the plurality of semiconductor chip CPs, and then forming the sealing and rewiring (hereinafter, "step (4B)". ) ”) Will be explained.

<Process (4A)>
The step (4A) is a step of sealing a plurality of semiconductor chip CPs on the pressure-sensitive adhesive sheet (A) with a sealing resin on the pressure-sensitive adhesive sheet (A) and then forming rewiring, and is a step of forming rewiring. It is preferable to have 1) to (4A to 3).
Step (4A-1): The plurality of semiconductor chip CPs and the peripheral portion of the plurality of semiconductor chip CPs on the adhesive surface of the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) are coated with a sealing material. Step of curing the encapsulant to obtain a cured encapsulant obtained by encapsulating the plurality of semiconductor chip CPs in the cured encapsulant (4A-2): Expanding the expandable particles to obtain an adhesive sheet A step of separating (A) from the cured sealant.
Step (4A-3): A step of forming a rewiring layer on a cured seal body from which the adhesive sheet (A) is separated. The adhesive sheet (A) is used when sealing a semiconductor chip as in the step (4A). It is also suitable as a temporary fixing sheet. In the pressure-sensitive adhesive sheet (A), since the expandable particles are contained not in the pressure-sensitive adhesive layer but in the non-adhesive resin having a high elastic modulus, the thickness of the pressure-sensitive adhesive layer (X1) on which the semiconductor chip is placed can be adjusted and adhered. The degree of freedom in design, such as control of force and viscoelasticity, is improved. As a result, it is possible to suppress the occurrence of misalignment of the semiconductor chip, suppress the semiconductor chip from sinking into the double-sided pressure-sensitive adhesive sheet, and form a rewiring layer forming surface having excellent flatness. Further, when the pressure-sensitive adhesive sheet (A) is used, since the semiconductor chip is placed on the pressure-sensitive adhesive surface of the pressure-sensitive adhesive layer (X1), the base material (Y1) containing the expandable particles and the rewiring layer forming surface are directly connected to each other. Never come in contact with. As a result, the residue derived from the expandable particles and a part of the greatly deformed pressure-sensitive adhesive layer adhere to the rewiring layer forming surface, and the uneven shape formed on the heat-expandable pressure-sensitive adhesive layer is transferred to the rewiring layer forming surface. It is suppressed that the smoothness is deteriorated, and a rewiring layer forming surface having excellent cleanliness and smoothness can be obtained.

[Step (4A-1)]
8 (a) to 8 (c) show a plurality of semiconductor chip CPs and peripheral portions 45 of the plurality of semiconductor chip CPs on the adhesive surface (X1a) of the pressure-sensitive adhesive layer (X1) with a sealing material 40. The sealing material 40 is cured (hereinafter, the process is also referred to as a “curing step”) by coating (hereinafter, the step is also referred to as a “coating step”), and a plurality of semiconductor chip CPs are cured and the sealing material 41 is formed. A cross-sectional view illustrating the step (4A-1) of obtaining the cured sealed body 50 sealed in is shown.

The encapsulant 40 has a function of protecting a plurality of semiconductor chip CPs and elements associated therewith from the external environment. The sealing material 40 is not particularly limited, and any material that has been conventionally used as a semiconductor sealing material can be appropriately selected and used.
The sealing material 40 has curability from the viewpoint of mechanical strength, heat resistance, insulating property, and the like, and examples thereof include a thermosetting resin composition and an energy ray-curable resin composition.
Examples of the thermosetting resin contained in the thermosetting resin composition which is the sealing material 40 include epoxy resin, phenol resin, cyanate resin, etc., and include mechanical strength, heat resistance, insulating property, and moldability. Epoxy resin is preferable from the viewpoint of the above.
In addition to the thermosetting resin, the thermosetting resin composition includes, if necessary, a curing agent such as a phenol resin-based curing agent and an amine-based curing agent, a curing accelerator, and an inorganic filler such as silica. It may contain an additive such as an elastomer.
The sealing material 40 may be solid or liquid at room temperature. The form of the encapsulant 40, which is solid at room temperature, is not particularly limited, and may be, for example, granular or sheet-like.
In the present embodiment, it is preferable to carry out the coating step and the curing step using a sheet-shaped sealing material (hereinafter, also referred to as “sheet-shaped sealing material”). In the method using the sheet-shaped sealing material, the sheet-shaped sealing material is placed so as to cover the plurality of semiconductor chip CPs and their peripheral portions 45, so that the plurality of semiconductor chip CPs and their peripheral portions 45 are covered with the sealing material. Cover with 40. At that time, it is preferable to heat and crimp while appropriately reducing the pressure by a vacuum laminating method or the like so that a portion where the sealing material 40 is not filled does not occur in the gap between the plurality of semiconductor chip CPs.

As a method of coating the plurality of semiconductor chip CPs and the peripheral portion 45 thereof with the sealing material 40, an arbitrary method is appropriately selected and applied from the methods conventionally applied to the semiconductor sealing step. For example, a roll laminating method, a vacuum pressing method, a vacuum laminating method, a spin coating method, a die coating method, a transfer molding method, a compression molding molding method, or the like can be applied.
In these methods, in order to improve the filling property of the sealing material 40, the sealing material 40 is usually heated at the time of coating to impart fluidity.
The temperature at which the thermosetting resin composition is heated in the coating step varies depending on the type of the sealing material 40, the type of the pressure-sensitive adhesive sheet (A), and the like, but is, for example, 30 to 180 ° C, and 50 to 170 ° C. Preferably, 70 to 150 ° C. is more preferable. 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. 8B, the sealing material 40 covers the entire exposed surface of the plurality of semiconductor chip CPs and is also filled in the gaps between the plurality of semiconductor chip CPs.

Next, as shown in FIG. 8C, after performing the coating step, the sealing material 40 is cured, and a plurality of semiconductor chip CPs are sealed in the curing sealing material 41. Get 50.
In the curing step, the temperature at which the sealing material 40 is cured varies depending on the type of the sealing material 40, the type of the adhesive sheet (A), and the like, but is, for example, 80 to 240 ° C., preferably 90 to 200 ° C. , 100-170 ° C. is more preferable. The heating time is, for example, 10 to 180 minutes, preferably 20 to 150 minutes, and more preferably 30 to 120 minutes.
By the step (4A-1), a cured sealing body 50 in which a plurality of semiconductor chip CPs separated by a predetermined distance are embedded in the curing sealing material 41 is obtained.

[Step (4A-2)]
Next, as shown in FIG. 8D, the pressure-sensitive adhesive sheet (A) is separated from the cured sealant 50.
The method for separating the adhesive sheet (A) is as described above.
In the present embodiment, an example in which the sealing step is performed in a state where the circuit surface W1 of the plurality of semiconductor chip CPs is in contact with the adhesive layer (X1) of the adhesive sheet (A) has been described, but the circuit surface W1 is The sealing step may be carried out in an exposed state (that is, a state in which the back surface of the chip is in contact with the pressure-sensitive adhesive layer (X1)). In this case, the circuit surface W1 of the plurality of semiconductor chip CPs is covered with the sealing resin, but after the sealing resin is cured, the cured sealing material is appropriately scraped off using a grinder or the like, and the cured sealing material is scraped again. The circuit surface W1 may be exposed.

[Step (4A-3): Rewiring layer forming step]
9 (a) to 9 (c) are cross-sectional views illustrating a step (4A-3) of forming a rewiring layer on the cured sealing body 50 from which the adhesive sheet (A) is separated.
FIG. 9B shows a cross-sectional view illustrating a step of forming the first insulating layer 61 on the circuit surface W1 of the semiconductor chip CP and the surface 50a of the cured sealant 50.
The first insulating layer 61 containing an insulating resin is formed on the circuit surface W1 and the surface 50a so as to expose the circuit W2 of the semiconductor chip CP or the internal terminal electrode W3 of the circuit W2. Examples of the insulating resin include a polyimide resin, a polybenzoxazole resin, and a 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 containing these metals.

FIG. 9C shows a cross-sectional view illustrating a step of forming the rewiring 70 that is electrically connected to the semiconductor chip CP sealed in the cured sealing body 50.
In the present 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 containing these metals. The rewiring 70 can be formed by a known method such as a subtractive method or a semi-additive method.

FIG. 10A shows a cross-sectional view illustrating a step of forming the second insulating layer 62 that covers the rewiring 70.
The rewiring 70 has an external electrode pad 70A for the external terminal electrode. An opening or the like is provided in the second insulating layer 62 to expose the external electrode pad 70A for the external terminal electrode. In the present embodiment, the external electrode pad 70A is inside and outside the region (region corresponding to the circuit surface W1) of the semiconductor chip CP of the cured sealant 50 (region corresponding to the surface 50a on the cured sealant 50). It is exposed to. Further, the rewiring 70 is formed on the surface 50a of the curing sealant 50 so that the external electrode pads 70A are arranged in an array. In the present embodiment, since the external electrode pad 70A is exposed outside the region of the semiconductor chip CP of the cured sealant 50, FOWLP or FOPLP can be obtained.

(Connection process with external terminal electrodes)
Next, the external terminal electrode 80 may be connected to the external electrode pad 70A, if necessary.
FIG. 10B shows a cross-sectional view illustrating a step of connecting the external terminal electrode 80 to the external electrode pad 70A.
An external terminal electrode 80 such as a solder ball is placed on the external electrode pad 70A exposed from the second insulating layer 62, and the external terminal electrode 80 and the external electrode pad 70A are electrically connected by solder joining 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 dicing process)
FIG. 10C shows a cross-sectional view illustrating a second dicing step of individualizing the cured sealant 50 to which the external terminal electrode 80 is connected.
In this step, the cured sealant 50 is individualized in units of semiconductor chip CP. The method for individualizing the cured sealant 50 is not particularly limited, and can be carried out by a cutting means such as a dicing saw.
By individualizing the cured sealant 50, the semiconductor device 100 of the semiconductor chip CP unit is manufactured. The semiconductor device 100 in which the external terminal electrode 80 is connected to the external electrode pad 70A fan-outed outside the region of the semiconductor chip CP as described above is manufactured as FOWLP, FOPLP, or the like.

(Mounting process)
In the present embodiment, it is also preferable to include a step of mounting the fragmented semiconductor device 100 on a printed wiring board or the like.

<Process (4B)>
Next, after the step (3), a plurality of semiconductor chip CPs are separated from the pressure-sensitive adhesive sheet (A), rearrangement for aligning the semiconductor chips is performed, and then sealing and rewiring are formed (4B). ) Will be explained. The step (4B) preferably includes the following steps (4B-1) and (4B-2).
Step (4B-1): A step of expanding the expandable particles to separate the pressure-sensitive adhesive sheet (A) from the plurality of semiconductor chip CPs.
Step (4B-2): A step of aligning the plurality of semiconductor chip CPs separated from the pressure-sensitive adhesive sheet (A).
The step (4B-2) is a step of aligning a plurality of semiconductor chip CPs separated from the adhesive sheet (A) by using an alignment jig provided with a plurality of accommodating portions capable of accommodating the plurality of semiconductor chip CPs. Is preferable.

[Step (4B-1)]
In FIGS. 11A and 11B, the pressure-sensitive adhesive sheet (A) and the plurality of semiconductor chip CPs are separated by expanding the expandable particles in the pressure-sensitive adhesive sheet (A), and the plurality of separated semiconductors are shown. A cross-sectional view illustrating a step (4B-1) of moving the chip CP to the alignment jig 10 mounted on the holding member 20 is shown. The alignment jig 10 includes a plurality of accommodating portions 11 capable of accommodating the semiconductor chip CP.
The conditions for separating the pressure-sensitive adhesive sheet (A) and the plurality of semiconductor chip CPs are as described above.
As shown in FIG. 11B, the holding member 20 has the alignment jig 10 mounted on the holding surface 21, and the semiconductor chip CP is placed in the accommodating portion 11 which is the opening of the alignment jig 10. It is contained.
The holding member 20 may adsorb and hold the semiconductor chip CP by a decompression means (not shown).
FIG. 12 shows a plan view of the alignment jig 10, and the alignment jig 10 includes a frame-shaped main body portion 12 and an accommodating portion 11 capable of accommodating the semiconductor chip CP. In the alignment jig 10, the accommodating portions 11 that open in a substantially square shape in a plan view are arranged in a square grid pattern.

[Step (4B-2)]
13 (a) and 13 (b) are cross-sectional views illustrating a step (4B-2) of aligning a plurality of semiconductor chip CPs separated from the pressure-sensitive adhesive sheet (A).
As shown in FIG. 13A, the plurality of semiconductor chip CPs separated from the adhesive sheet (A) are housed in the accommodating portion 11 of the alignment jig 10 including the plurality of accommodating portions 11 capable of accommodating the plurality of semiconductor chip CPs. It will be placed.
Next, as shown in FIG. 13B, the alignment jig 10 on the holding member 20 is moved in the X and Y directions to move the wall portion 11a of the alignment jig 10 and the side surface CPa of the semiconductor chip CP. To abut. At this time, the holding member 20 itself or both the holding member 20 and the alignment jig 10 may be moved so that the wall portion 11a of the alignment jig 10 and the side surface CPa of the semiconductor chip CP are brought into contact with each other.
As a result, as shown in FIG. 13B, a plurality of aligned semiconductor chip CPs are obtained.

The plurality of semiconductor chip CPs aligned in the step (4B) are then transferred to the temporary fixing sheet such as the adhesive sheet (A) again after performing the inversion step and the transfer step as necessary. Then, FOWLP and FOPLP can be produced through the same sealing step and rewiring forming step as in the step (4A).

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to the following examples. The physical property values in the following production examples and examples are values measured by the following methods.

<Mass average molecular weight (Mw)>
It was measured under the following conditions using a gel permeation chromatograph device (manufactured by Tosoh Corporation, product name "HLC-8020"), and the value measured in terms of standard polystyrene was used.
(Measurement condition)
-Column: "TSK guard volume HXL-L""TSK gel G2500HXL""TSK gel G2000HXL""TSK gel G1000HXL" (all manufactured by Tosoh Corporation) are connected in sequence.-Column temperature: 40 ° C.
-Development solvent: tetrahydrofuran-Flow velocity: 1.0 mL / min

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

<Average particle size of thermally expandable particles (D ₅₀ ), 90% particle size (D ₉₀ )>
Using a laser diffraction type particle size distribution measuring device (for example, manufactured by Malvern, product name “Master Sizar 3000”), the particle distribution of the thermally expandable particles before expansion at 23 ° C. was measured.
Then, the particle diameters corresponding to the cumulative volume frequencies of 50% and 90% calculated from the smaller particle diameter of the particle distribution are set to "average particle diameter of thermally expandable particles (D ₅₀ )" and "thermally expandable particles", respectively. 90% particle size (D ₉₀ ).

<Storage modulus E'of expansive substrate>
When the measurement target was a non-adhesive expandable base material, the expandable base material had a size of 5 mm in length × 30 mm in width × 200 μm in thickness, and the one from which the release material was removed was used as a test sample.
Using a dynamic viscoelasticity measuring device (manufactured by TA Instruments, product name "DMAQ800"), the test start temperature is 0 ° C, the test end temperature is 300 ° C, the temperature rise rate is 3 ° C / min, the frequency is 1 Hz, and the amplitude is 20 μm. The storage elastic modulus E'of the test sample at a predetermined temperature was measured under the conditions of.

<Storage shear modulus G'of the adhesive layer>
When the object to be measured was an adhesive layer having adhesiveness, the adhesive layer had a diameter of 8 mm and a thickness of 3 mm, and the one from which the release material was removed was used as a test sample.
Torsional shearing method using a viscoelasticity measuring device (manufactured by Antonio Par, device name "MCR300") under the conditions of test start temperature 0 ° C, test end temperature 300 ° C, temperature rise rate 3 ° C / min, and frequency 1 Hz. The stored shear viscoelasticity G'of the test sample at a predetermined temperature was measured. Then, the value of the storage elastic modulus E'was calculated from the approximate formula "E'= 3G'" based on the measured value of the storage shear elastic modulus G'.

<Probe tack value>
The expansive substrate or adhesive layer to be measured was cut into squares with a side of 10 mm and then allowed to stand in an environment of 23 ° C. and 50% RH (relative humidity) for 24 hours to remove the light release film. It was used as a test sample.
The light release film was removed from the test sample using a tacking tester (manufactured by Japanese Industrial Standards Co., Ltd., product name "NTS-4800") in an environment of 23 ° C. and 50% RH (relative humidity). The probe tack value on the surface of the test sample expressed as described above was measured according to JIS Z0237: 1991.
Specifically, a stainless steel probe having a diameter of 5 mm is brought into contact with the surface of the test sample for 1 second with a contact load of 0.98 N / cm ² , and then the probe is brought into contact with the surface of the test sample at a speed of 10 mm / sec. The force required to separate it from the surface was measured. Then, the measured value was used as the probe tack value of the test sample.

Details of the adhesive resin, additives, heat-expandable particles, and release material used in the formation of each layer in the following production examples are as follows.
<Adhesive resin>
Acrylic copolymer (i): has a structural unit derived from a raw material monomer composed of 2-ethylhexyl acrylate (2EHA) / 2-hydroxyethyl acrylate (HEA) = 80.0 / 20.0 (mass ratio). A solution containing an acrylic copolymer of Mw 600,000. Diluting solvent: ethyl acetate, solid content concentration: 40% by mass.
-Acrylic copolymer (ii): n-butyl acrylate (BA) / methyl methacrylate (MMA) / 2-hydroxyethyl acrylate (HEA) / acrylic acid = 86.0 / 8.0 / 5.0 / 1. A solution containing an acrylic copolymer of Mw 600,000, which has a structural unit derived from a raw material monomer consisting of 0 (mass ratio). Diluting solvent: ethyl acetate, solid content concentration: 40% by mass.
<Additives>
-Isocyanate cross-linking agent (i): manufactured by Tosoh Corporation, product name "Coronate L", solid content concentration: 75% by mass.
-Photopolymerization initiator (i): manufactured by BASF, product name "Irgacure 184", 1-hydroxy-cyclohexyl-phenyl-ketone.
<Thermal expandable particles>
-Thermal 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. ..
<Release material>
-Heavy release film: manufactured by Lintec Corporation, product name "SP-PET382150", polyethylene terephthalate (PET) film provided with a release agent layer formed from a silicone-based release agent on one side, thickness: 38 μm.
-Light release film: manufactured by Lintec Corporation, product name "SP-PET381031", PET film provided with a release agent layer formed from a silicone-based release agent on one side, thickness: 38 μm.

Manufacturing example 1
(Formation of adhesive layer (X1))
5.0 parts by mass (solid content ratio) of the isocyanate-based cross-linking agent (i) is added to 100 parts by mass of the solid content of the solution of the acrylic copolymer (i), which is an adhesive resin, and diluted with toluene. Then, the mixture was uniformly stirred to prepare a pressure-sensitive adhesive composition (x1) having a solid content concentration (active ingredient concentration) of 25% by mass.
Then, the prepared pressure-sensitive adhesive composition (x1) is applied onto the surface of the release agent layer of the heavy-release film to form a coating film, and the coating film is dried at 100 ° C. for 60 seconds to have a thickness of 10 μm. Adhesive layer (X1) was formed. Incidentally, at 23 ° C., the storage shear modulus G of the pressure-sensitive adhesive layer (X1) '(23) was 2.5 × ¹⁰ 5 Pa.

Manufacturing example 2
(Formation of adhesive layer (X1'))
0.8 parts by mass (solid content ratio) of the isocyanate-based cross-linking agent (i) is added to 100 parts by mass of the solid content of the solution of the acrylic copolymer (ii), which is an adhesive resin, and diluted with toluene. Then, the mixture was uniformly stirred to prepare a pressure-sensitive adhesive composition (x1') having a solid content concentration (active ingredient concentration) of 25% by mass. Then, the prepared pressure-sensitive adhesive composition (x1') is applied onto the surface of the release agent layer of the light release film to form a coating film, and the coating film is dried at 100 ° C. for 60 seconds to obtain a thickness. A 10 μm pressure-sensitive adhesive layer (X1') was formed. The storage shear elastic modulus G'(23) of the pressure-sensitive adhesive layer (X1') at 23 ° C. was 9.0 × 10 ³ Pa.

Manufacturing example 3
(Formation of expandable base material (Y1-1))
2-Hydroxyethyl acrylate is reacted with the terminal isocyanate urethane prepolymer obtained by reacting the ester-type diol with isophorone diisocyanate (IPDI) to obtain a bifunctional acrylic urethane-based oligomer having a mass average molecular weight (Mw) of 5000. Obtained.
Then, 40% by mass (solid content ratio) of the acrylic urethane-based oligomer synthesized above, 40% by mass (solid content ratio) of isobornyl acrylate (IBXA) and phenylhydroxypropyl acrylate (HPPA) as energy ray-polymerizable monomers. ) 20 parts by mass (solid content ratio) is blended, and 2.0 parts by mass (solid content ratio) of the photopolymerization initiator (i) is further added to 100 parts by mass of the total amount of the acrylic urethane-based oligomer and the energy ray-polymerizable monomer. , And 0.2 parts by mass (solid content ratio) of the phthalocyanine-based pigment was blended as an additive to prepare an energy ray-curable composition. The heat-expandable particles (i) were blended with the energy ray-curable composition to prepare a solvent-free resin composition (y1) containing no solvent. The content of the heat-expandable particles (i) was 20% by mass with respect to the total amount (100% by mass) of the resin composition (y1).
Next, the prepared resin composition (y1) was applied onto the surface of the release agent layer of the light release film to form a coating film. Then, using an ultraviolet irradiation device (manufactured by Eye Graphics, product name "ECS-401GX") and a high-pressure mercury lamp (manufactured by Eye Graphics, product name "H04-L41"), the illuminance is 160 mW / cm ² , and the light intensity is 500 mJ /. The coating film was cured by irradiating with ultraviolet rays under the condition of cm ² , and an expandable base material (Y1-1) having a thickness of 50 μm was formed. The above-mentioned illuminance and amount of light during ultraviolet irradiation are values measured using an illuminance / light intensity meter (manufactured by EIT, product name "UV Power Pack II").
Incidentally, the obtained storage elastic modulus E at 23 ° C. of expandable substrate (Y1-1) 'is the storage modulus E at ^{5.0 × 10 8 Pa, 100 ℃} ' above is 4.0 × 10 The storage elastic modulus E'at ⁶ Pa and 208 ° C. was 4.0 × 10 ⁶ Pa. The probe tack value of the expandable base material (Y1-1) was 2 mN / 5 mmφ.

Manufacturing example 4
(Preparation of adhesive sheet (A))
The surfaces of the pressure-sensitive adhesive layer (X1) formed in Production Example 1 and the expandable base material (Y1-1) formed in Production Example 3 are bonded to each other, and lightly peeled off on the expandable base material (Y1-1) side. The film was removed, and the pressure-sensitive adhesive layer (X1') formed in Production Example 2 was laminated on the surface of the exposed expandable base material (Y1-1). As a result, a pressure-sensitive adhesive sheet (A) in which a light release film / pressure-sensitive adhesive layer (X1') / expandable base material (Y1-1) / pressure-sensitive adhesive layer (X1) / heavy-release film was laminated in this order was produced.

Production example 5
(Preparation of adhesive sheet (B) (expanded tape))
An acrylic copolymer obtained by reacting butyl acrylate / 2-hydroxyethyl acrylate = 85/15 (mass ratio) and 80 mol% of methacryloxyethyl isocyanate (MOI) with respect to the 2-hydroxyethyl acrylate. And were reacted to obtain an energy ray-curable polymer. The mass average molecular weight (Mw) of this energy ray-curable polymer was 600,000. 100 parts by mass of the obtained energy ray-curable polymer, 3 parts by mass of 1-hydroxycyclophenylketone (manufactured by BASF, product name "Irgacure 184") as a photopolymerization initiator, and tolylene diisocyanate as a cross-linking agent. 0.45 parts by mass of a system cross-linking agent (manufactured by Tosoh Corporation, product name "Coronate L") was mixed in a solvent to obtain an adhesive composition.
Next, with respect to the surface separation surface of the release film (manufactured by Lintec Corporation, product name "SP-PET3811") in which a silicone-based release agent layer is formed on one side of the polyethylene terephthalate (PET) film. The pressure-sensitive adhesive composition was applied and dried by heating to form a pressure-sensitive adhesive layer (X2) having a thickness of 10 μm on the release film. Then, one side of a polyester-based polyurethane elastomer sheet (manufactured by Seadam, product name "Higres DUS202", thickness 50 μm) is bonded to the exposed surface of the pressure-sensitive adhesive layer as a base material (Y2) to form a pressure-sensitive adhesive layer. An adhesive sheet (B) (expanded tape) was obtained with the release film attached to the surface.

[Manufacturing of semiconductor devices]
Example 1
Using the pressure-sensitive adhesive sheet (A) and the pressure-sensitive adhesive sheet (B) obtained above, a semiconductor device was manufactured by the following method.
<Process (1)>
The adhesive sheet (B) obtained in Production Example 5 was cut into a size of 210 mm × 210 mm. At this time, each side of the sheet after cutting was cut so as to be parallel or perpendicular to the MD direction of the base material (Y2) of the adhesive sheet (B). Next, a plurality of semiconductor chips (1800 pieces) obtained by peeling the release sheet from the adhesive sheet (B) and dicing a semiconductor wafer (diameter: 150 mm, thickness: 350 μm) are formed by the circuit forming surface W1. It was attached on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) so as to be on the opposite side to the pressure-sensitive adhesive layer (X2). At this time, a group of semiconductor chips were transferred so as to be located at the center of the pressure-sensitive adhesive sheet (B). Further, the dicing line when the semiconductor wafer was separated was transferred so as to be parallel or perpendicular to each side of the pressure-sensitive adhesive sheet (B).

Subsequently, the pressure-sensitive adhesive sheet (B) to which the plurality of semiconductor chips were attached was installed in the biaxially stretchable expanding device. As shown in FIG. 14, the expanding device has an X-axis direction (a positive direction is a + X-axis direction and a negative direction is a -X-axis direction) and a Y-axis direction (a positive direction is a + Y-axis direction) that are orthogonal to each other. , The negative direction is the −Y axis direction), and has a holding means for extending 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 aligned with the X-axis or Y-axis direction, the adhesive sheet (B) is installed in the expanding device, and each side of the adhesive sheet (B) is gripped by the holding means, and then under the following conditions. , The pressure-sensitive adhesive sheet (B) was stretched to widen the distance between the plurality of semiconductor chips attached on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B).
・ Number of holding means: 5 per side ・ Stretching speed: 5 mm / sec
-Stretching distance: Each side was stretched by 60 mm.

<Process (2)>
Next, the adhesive sheet (A) obtained in Production Example 4 was cut into a size of 230 mm × 230 mm.
The heavy-release film and the light-release film are peeled off from the adhesive sheet (A) after cutting, and the exposed pressure-sensitive adhesive layer (X1) is opposite to the surface in contact with the pressure-sensitive adhesive layers (X2) of the plurality of semiconductor chips. A support (SUS plate, thickness 1 mm, size: 200 mmφ) was attached to the surface of the exposed pressure-sensitive adhesive layer (X1') after being attached to the side surface.

<Process (3)>
Next, ultraviolet rays were irradiated from the surface of the pressure-sensitive adhesive sheet (B) on the substrate side to an illuminance of 230 mW / cm ² and a light intensity of 190 mJ / cm ² to cure the pressure-sensitive adhesive layer, and the plurality of the pressure-sensitive adhesive sheets were attached to the pressure-sensitive adhesive sheet (A). The semiconductor chip and the adhesive sheet (B) were separated.
As a result, a plurality of semiconductor chips placed on the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) at regular intervals were obtained.

<Process (4A-1)>
Next, a sealing resin film (sealing material) is laminated on the adhesive surface (X1) and a plurality of semiconductor chips, and a vacuum heating and pressurizing laminator (“7024HP5” manufactured by ROHM and HAAS) is used. The adhesive surface of the pressure-sensitive adhesive layer (X1) and the semiconductor chip were covered with a sealing material, and the sealing material was cured to prepare a cured sealant. The sealing conditions are as follows.
・ Preheating temperature: 100 ° C for both table and diaphragm
・ Vacuuming: 60 seconds ・ Dynamic press mode: 30 seconds ・ Static press mode: 10 seconds ・ Sealing temperature: 180 ° C (temperature lower than 208 ° C, which is the expansion start temperature of thermally expandable particles)
・ Sealing time: 60 minutes

<Process (4A-2)>
After sealing, the pressure-sensitive adhesive sheet (A) was heated at 240 ° C., which is equal to or higher than the expansion start temperature (208 ° C.) of the heat-expandable particles, for 3 minutes to separate the cured sealant from the pressure-sensitive adhesive sheet (A). When the pressure-sensitive adhesive sheet (A) was separated, the pressure-sensitive adhesive sheet (A) could be separated all at once while being kept flat without bending.

From the above results, according to the manufacturing method of the present embodiment, the chips whose intervals have been widened by the expanding step can be easily separated from the expanding tape all at once while maintaining the intervals, and the separated chips can be obtained. It can be seen that it can be easily applied to the next step (sealing step). Further, since the adhesive force of the pressure-sensitive adhesive sheet (A) can be remarkably reduced by expanding the expandable particles, the pressure-sensitive adhesive sheet (A) can be easily separated after the sealing step.

Next, the separability of the pressure-sensitive adhesive sheet (A) used in this embodiment was evaluated by the following test.

[Measurement of adhesive strength of adhesive sheet]
(Measurement of adhesive strength before and after heating of adhesive sheet (A))
The light release film of the produced adhesive sheet (A) was removed, and a polyethylene terephthalate (PET) film with a thickness of 50 μm (manufactured by Toyobo Co., Ltd., product name " Cosmo Shine A4100 ") was laminated to form an adhesive sheet with a base material. Next, the heavy release film of the pressure-sensitive adhesive sheet (A) was also removed, and the pressure-sensitive adhesive surface of the exposed pressure-sensitive adhesive layer (X1) was attached to a stainless steel plate (SUS304 No. 360 polishing) as an adherend at 23 ° C. The test sample was left to stand for 24 hours in an environment of 50% RH (relative humidity).
Adhesive strength at 23 ° C. at a tensile speed of 300 mm / min by 180 ° peeling method based on JIS Z0237: 2000 in an environment of 23 ° C. and 50% RH (relative humidity) using the above test sample. Was measured.
Further, the above test sample is heated on a hot plate at 240 ° C., which is equal to or higher than the expansion start temperature (208 ° C.) of the heat-expandable particles, for 3 minutes in a standard environment (23 ° C., 50% RH (relative humidity)). ) For 60 minutes, the adhesive strength after heating at the expansion start temperature or higher was also measured under the same conditions as above.

(Measurement of adhesive strength of comparative adhesive sheet before and after UV irradiation)
The adhesive surface of the comparative adhesive sheet (manufactured by Lintec Corporation, trade name "D-820") is attached to a stainless steel plate (SUS304 360 polishing) as an adherend, and 23 ° C., 50% RH (relative humidity). The test sample was left to stand for 24 hours in the above environment, and the adhesive strength at 23 ° C. before irradiation with ultraviolet rays was measured under the same conditions as the adhesive sheet (A).
Then, from the substrate side of comparative pressure-sensitive adhesive sheet, illumination with ultraviolet light 230 mW / cm ^2, it was irradiated with light quantity 190 mJ / cm ^2, under the same conditions as above, were measured adhesion at 23 ° C. after ultraviolet irradiation.

From Table 1, it can be seen that the adhesive sheet (A) used in the present embodiment has a smaller adhesive force after the expansion of the expandable particles than the comparative adhesive sheet after irradiation with ultraviolet rays, and has excellent separability. .. Therefore, according to the manufacturing method of the present embodiment, for example, even when the rearrangement step is carried out as the next step, the semiconductor chip is separated more easily than the conventional ultraviolet irradiation type pressure-sensitive adhesive sheet and subjected to the rearrangement step. It is possible.

1a Adhesive sheet (a)
1b Adhesive sheet (a)
10 Alignment jig 11 Containment part 11a Wall part of alignment jig 12 Frame-shaped main body part 20 Holding member 40 Encapsulant 41 Curing encapsulant 45 Peripheral part of semiconductor chip CP 50 Curing encapsulant 50a Surface 61 First insulation Layer 62 Second insulating layer 70 Rewiring 70A External electrode pad 80 External terminal electrode 100 Semiconductor device 200 Expanding device 210 Holding means CP Semiconductor chip CPa Semiconductor chip side surface W1 Circuit surface W2 circuit W3 Internal terminal electrode

Claims (10)

A method for manufacturing a semiconductor device using an expandable pressure-sensitive adhesive sheet (A) having a base material (Y1) containing expandable particles and an adhesive layer (X1).
A semiconductor device having the following steps (1) to (3) in this order, and after the step (3), the expansive particles of the pressure-sensitive adhesive sheet (A) are expanded to separate the pressure-sensitive adhesive sheet (A) from the adherend. Manufacturing method.
Step (1): The distance between a plurality of chips placed on the pressure-sensitive adhesive layer (X2) of the pressure-sensitive adhesive sheet (B) having the base material (Y2) and the pressure-sensitive adhesive layer (X2) is set by the pressure-sensitive adhesive sheet (B). The process of stretching and spreading.
Step (2): A step of attaching the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) to the surface of the plurality of chips opposite to the surface in contact with the pressure-sensitive adhesive layers (X2).
Step (3): A step of separating the plurality of chips attached to the adhesive sheet (A) from the adhesive sheet (B). The expandable particles are thermally expandable particles having an expansion start temperature (t) of 60 to 270 ° C., and the heat-expandable particles are expanded by heating the adhesive sheet (A) after the step (3). The method for manufacturing a semiconductor device according to claim 1, wherein the adhesive sheet (A) is separated from an adherend. The semiconductor device according to claim 1 or 2, wherein the adhesive force of the pressure-sensitive adhesive layer (X1) of the pressure-sensitive adhesive sheet (A) before expanding the expandable particles is 0.1 to 10.0 N / 25 mm. Production method. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein the probe tack value on the surface of the base material (Y1) contained in the pressure-sensitive adhesive sheet (A) is less than 50 mN / 5 mmφ. The method for manufacturing a semiconductor device according to any one of claims 1 to 4, wherein the chip is a semiconductor chip. The method for manufacturing a semiconductor device according to claim 5, further comprising the following steps (4A-1) to (4A-3).
Step (4A-1): The plurality of semiconductor chips and the peripheral portion of the plurality of semiconductor chips on the adhesive surface of the pressure-sensitive adhesive layer (X1) are covered with a sealing material, and the sealing material is cured. A step of obtaining a cured sealant obtained by sealing the plurality of semiconductor chips with a cured sealant.
Step (4A-2): A step of expanding the expandable particles to separate the pressure-sensitive adhesive sheet (A) from the cured sealant.
Step (4A-3): A step of forming a rewiring layer on the cured seal body from which the adhesive sheet (A) has been separated. The method for manufacturing a semiconductor device according to claim 5, further comprising the following steps (4B-1) and (4B-2).
Step (4B-1): A step of expanding the expandable particles to separate the pressure-sensitive adhesive sheet (A) from the plurality of semiconductor chips.
-Step (4B-2): A step of aligning the plurality of semiconductor chips separated from the adhesive sheet (A). The step (4B-2) is a step of aligning the plurality of semiconductor chips separated from the pressure-sensitive adhesive sheet (A) by using an aligning jig provided with a plurality of accommodating portions capable of accommodating the plurality of semiconductor chips. The method for manufacturing a semiconductor device according to claim 7. The method for manufacturing a semiconductor device according to any one of claims 1 to 8, wherein the pressure-sensitive adhesive sheet (B) has a breaking elongation of 100% or more measured in the MD direction and the CD direction at 23 ° C. The method for manufacturing a semiconductor device according to any one of claims 1 to 9, which is a method for manufacturing a fan-out type semiconductor device.

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