WO2021065070A1

WO2021065070A1 - Adhesive sheet and method for producing adhesive sheet

Info

Publication number: WO2021065070A1
Application number: PCT/JP2020/020327
Authority: WO
Inventors: 高野　健
Original assignee: リンテック株式会社
Priority date: 2019-10-04
Filing date: 2020-05-22
Publication date: 2021-04-08
Also published as: KR20220080093A; JPWO2021065074A1; TW202122532A; CN114514296A; JPWO2021065071A1; TW202116947A; JPWO2021065072A1; WO2021065072A1; CN114514295A; TW202115214A; JPWO2021065070A1; CN114514296B; CN114502679A; TW202122534A; WO2021065073A1; KR20220075341A; WO2021065071A1; CN114514295B; WO2021065074A1; KR20220080092A

Abstract

An adhesive sheet (1A) which has a base material (10) and an adhesive layer (20), wherein: both edges of the adhesive layer (20), which contains an energy ray-curable resin, in the width direction have cured parts (22) where the energy ray-curable resin is cured and uncured parts (21); and the tensile strength F_A1 at a tensile elongation of 0.5 mm as determined by means of a tensile testing machine by preparing a first test piece having a width of 25 mm from a region corresponding to the uncured parts (21) and holding both ends of the first test piece in the longitudinal direction by a holding tool and the tensile strength F_B1 at a tensile elongation of 0.5 mm as determined by means of a tensile testing machine by preparing a second test piece by bonding a first semiconductor chip to one end of the first test piece in the longitudinal direction and bonding a second semiconductor chip to the other end thereof in the longitudinal direction, said first semiconductor chip and second semiconductor chip having a length of 45 mm, a width of 35 mm and a thickness of 0.625 mm, and holding the both ends of the second test piece in the longitudinal direction by a holding tool satisfy the relationship of mathematical formula (1A). (1A): F_B1/F_A1 ≤ 30

Description

Adhesive sheet and manufacturing method of adhesive sheet

The present invention relates to an adhesive sheet and a method for manufacturing an adhesive sheet.

In recent years, electronic devices have become smaller, lighter, and more sophisticated. 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 referred to as a chip scale package (CSP). One of the CSPs is a wafer level package (WLP). In the WLP, an external electrode or the like is formed on the wafer before it is separated by dicing, and finally the wafer is diced and separated. Examples of the WLP include a fan-in type and a fan-out type. In a fan-out type WLP (hereinafter, may be abbreviated as "FO-WLP"), the semiconductor chip is covered with a sealing member so as to have a region larger than the chip size, and the semiconductor chip sealant is covered. 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 sealing member.

For example, in Patent Document 1, an expansion wafer is formed by surrounding a plurality of semiconductor chips separated from a semiconductor wafer by using a mold member, leaving a circuit forming surface thereof, and forming an expansion wafer 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, before enclosing a plurality of individualized semiconductor chips with a mold member, they are replaced with a wafer mount tape for expansion, and the wafer mount tape is spread to form a plurality of semiconductor chips. The distance between them is increasing.

International Publication No. 2010/058646

In the expanding step, a tape or sheet to which a plurality of semiconductor chips are attached is spread to increase the distance between the semiconductor chips. When the sheet is pulled and spread, if the amount of elongation differs within the sheet surface, it is difficult to evenly expand the distance between the semiconductor chips.
In addition, there may be a problem that the pressure-sensitive adhesive contained in the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet exudes from the end portion in the width direction of the sheet.

An object of the present invention is to obtain an adhesive sheet having excellent expandability by reducing the difference in the amount of elongation of the adhesive sheet in the in-plane direction when the adhesive sheet is expanded in the expanding step to extend the distance between semiconductor chips. To provide.
Another object of the present invention is to suppress the seepage of the pressure-sensitive adhesive, and to extend the pressure-sensitive adhesive sheet in the expanding step to extend the distance between the semiconductor chips, and to increase the amount of elongation of the pressure-sensitive adhesive sheet in the in-plane direction. It is an object of the present invention to provide a pressure-sensitive adhesive sheet having a small difference and excellent expandability, and a method for manufacturing the pressure-sensitive adhesive sheet.

The pressure-sensitive adhesive sheet according to one aspect of the present invention has a base material and a pressure-sensitive adhesive layer.
A first test piece having a width of 25 mm is prepared from the pressure-sensitive adhesive sheet, and the base material and the pressure-sensitive adhesive layer at both ends of the first test piece in the longitudinal direction are gripped by a gripper and subjected to a tensile tester. and the tensile strength _{F A1} when pulling 0.5mm,
The first semiconductor chip and the second semiconductor chip having a vertical dimension of 45 mm, a horizontal dimension of 35 mm, and a thickness dimension of 0.625 mm are the vertical dimensions of the first semiconductor chip and the second semiconductor chip. Is 45 mm along the longitudinal direction of the first test piece, and the distance between the first semiconductor chip and the second semiconductor chip is 35 μm, in the longitudinal direction of the first test piece. The first semiconductor chip is attached to the pressure-sensitive adhesive layer on one end side, and the second semiconductor chip is attached to the pressure-sensitive adhesive layer on the other end side in the longitudinal direction of the first test piece. When a test piece is prepared, the base material, the pressure-sensitive adhesive layer, and the semiconductor chip at both ends in the longitudinal direction of the second test piece are gripped with a gripping tool and pulled by a tensile tester by 0.5 mm. The tensile strength _FB1 and Satisfy the relationship of the following formula (Equation 1A).
F _B1 / F _A1 ≤ 30 ... (Equation 1A)

The pressure-sensitive adhesive sheet according to one aspect of the present invention has a base material and a pressure-sensitive adhesive layer.
The pressure-sensitive adhesive layer contains an energy ray-curable resin and contains
The pressure-sensitive adhesive layer has a cured portion in which the energy ray-curable resin is cured at both ends in the width direction of the pressure-sensitive adhesive layer, and an uncured portion in which the energy ray-curable resin is not cured.
A first test piece having a width of 25 mm is prepared from the pressure-sensitive adhesive sheet in the region corresponding to the uncured portion, and the base material and the pressure-sensitive adhesive layer at both ends of the first test piece in the longitudinal direction. and the tensile strength F _A1 when pulling 0.5mm by gripping to a tensile tester uncured portions in the jaws,
The first semiconductor chip and the second semiconductor chip having a vertical dimension of 45 mm, a horizontal dimension of 35 mm, and a thickness dimension of 0.625 mm are the vertical dimensions of the first semiconductor chip and the second semiconductor chip. Is 45 mm along the longitudinal direction of the first test piece, and the distance between the first semiconductor chip and the second semiconductor chip is 35 μm, in the longitudinal direction of the first test piece. The first semiconductor chip is attached to the pressure-sensitive adhesive layer of the uncured portion on one end side, and the second semiconductor chip is attached to the pressure-sensitive adhesive layer of the uncured portion on the other end side in the longitudinal direction of the first test piece. A semiconductor chip is attached to prepare a second test piece, and the base material, the pressure-sensitive adhesive layer of the uncured portion, and the semiconductor chip at both ends in the longitudinal direction of the second test piece are gripped. in the tensile strength _{F B1} when gripped by the tensile 0.5mm by a tensile tester, but satisfies the following equation (equation 1A).
F _B1 / F _A1 ≤ 30 ... (Equation 1A)

In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the pressure-sensitive adhesive sheet is cut into a size of 150 mm in length and 25 mm in width along the elongated direction of the pressure-sensitive adhesive sheet so as to include a cured portion in which the energy ray-curable resin is cured. When three test pieces were prepared, the third test piece was gripped by a pair of chucks with a chuck-to-chuck distance of 100 mm, and extended to a chuck-to-chuck distance of 200 mm at a speed of 5 mm / sec, the cured portion. It is preferable that the interface between the substrate and the substrate does not float.

In the pressure-sensitive adhesive sheet according to one aspect of the present invention
The adhesive sheet is placed in the first direction, the second direction opposite to the first direction, the third direction perpendicular to the first direction, and the direction opposite to the third direction. When the area ratio (S2 / S1) × 100 of the area S1 of the pressure-sensitive adhesive sheet before stretching and the area S2 of the pressure-sensitive adhesive sheet after stretching is 381%, the pressure-sensitive adhesive layer is stretched in four directions. It is preferable that the cured portion of the above does not peel off at the interface with the base material.

The adhesive sheet according to an embodiment of the present invention, the tensile strength F _A1, wherein the tensile strength F _B1, but it is preferable to satisfy the following relationship formula (Equation 1B).
1 ≤ F _B1 / F _A1 ≤ 30 ... (Equation 1B)

In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the Young's modulus Y _A1 _{of the first test piece and the Young's modulus Y B1} of the second test piece satisfy the relationship of the following mathematical formula (Equation 2A). Is preferable.
Y _B1 / Y _A1 ≤ 19 ... (Equation 2A)

In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the pressure-sensitive adhesive layer preferably contains an acrylic pressure-sensitive adhesive.

In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the base material preferably contains a urethane-based elastomer.

The pressure-sensitive adhesive sheet according to one aspect of the present invention is preferably used in an expanding step for expanding the distance between a plurality of semiconductor chips during the manufacturing process of a semiconductor device.

The pressure-sensitive adhesive sheet according to one aspect of the present invention has a long shape and is wound in a roll shape.
Adhesive sheet.

The method for producing an adhesive sheet according to one aspect of the present invention is
A step of applying a pressure-sensitive adhesive composition containing an energy ray-curable resin onto a base material to form a pressure-sensitive adhesive layer,
A step of irradiating both ends of the pressure-sensitive adhesive layer in the width direction with energy rays to cure the energy ray-curable resin to form a cured portion.
The entire cured portion is left outside the both ends in the width direction of the uncured portion in which the energy ray-curable resin is not cured, or a part of the cured portion is left outside the cured portion. It has a step of cutting.

In the method for producing an adhesive sheet according to one aspect of the present invention.
The width of the cured portion left outside the both ends in the width direction of the uncured portion is preferably 0.5 mm or more independently.

In the method for producing an adhesive sheet according to one aspect of the present invention.
After the step of cutting the outside of the cured portion, it is preferable to further have a step of winding the cut adhesive sheet into a roll shape.

According to one aspect of the present invention, when the pressure-sensitive adhesive sheet is expanded in the expanding step to extend the distance between semiconductor chips, the difference in the amount of elongation of the pressure-sensitive adhesive sheet in the in-plane direction can be reduced, and the expandability is excellent. Adhesive sheets can be provided.
According to another aspect of the present invention, when the pressure-sensitive adhesive is suppressed from seeping out and the pressure-sensitive adhesive sheet is spread in the expanding step to increase the distance between the semiconductor chips, the pressure-sensitive adhesive sheet is in the in-plane direction. It is possible to provide a pressure-sensitive adhesive sheet having an excellent expandability and a method for manufacturing the pressure-sensitive adhesive sheet, which can reduce the difference in the amount of elongation.

It is sectional drawing of the adhesive sheet which concerns on one Embodiment. It is the schematic which shows the state which the 1st test piece was grasped by the gripper of the tensile tester. It is the schematic which shows the state which the 2nd test piece was grasped by the gripper of the tensile tester. It is sectional drawing of the adhesive sheet which concerns on another embodiment. It is a perspective view which shows the state which the adhesive sheet which concerns on another embodiment is wound up in a roll shape. It is sectional drawing which shows the manufacturing method of the adhesive sheet which concerns on another embodiment. It is sectional drawing which shows the manufacturing method of the adhesive sheet which concerns on another embodiment. It is sectional drawing which shows the manufacturing method of the adhesive sheet which concerns on another embodiment. It is a top view explaining the biaxial stretching expanding apparatus used in an Example.

Hereinafter, an embodiment of the present invention will be described.

[First Embodiment]
[Adhesive sheet]
The pressure-sensitive adhesive sheet according to this embodiment has a base material and a pressure-sensitive adhesive layer. The shape of the adhesive sheet can be any shape such as a tape shape (long form) and a label shape (single leaf shape).
FIG. 1 is a schematic cross-sectional view of an example of the pressure-sensitive adhesive sheet according to the present embodiment. FIG. 1 shows a pressure-sensitive adhesive sheet 1 having a base material 10 and a pressure-sensitive adhesive layer 20.

In the pressure-sensitive adhesive sheet according to the present embodiment, the ratio of the tensile strength of the first test piece and the second test piece produced from the pressure-sensitive adhesive sheet measured by a tensile tester satisfies a predetermined range.

(First test piece)
The first test piece is made from the pressure-sensitive adhesive sheet according to the present embodiment. The width of the first test piece is 25 mm.

In FIG. 2, the base material 10 and the adhesive layer 20 on one end side of the first test piece are gripped by the first gripper 110 of the tensile tester, and the base material 10 and the adhesive layer 20 on the other end side of the first test piece are held. It is the schematic which shows the state which the pressure-sensitive adhesive layer 20 was gripped by the second gripping tool 120 of a tensile tester.

(Second test piece)
The second test piece is produced by attaching two semiconductor chips to the first test piece produced from the pressure-sensitive adhesive sheet according to the present embodiment. In the present embodiment, the two semiconductor chips are a first semiconductor chip and a second semiconductor chip. Both the first semiconductor chip and the second semiconductor chip have a vertical dimension of 45 mm, a horizontal dimension of 35 mm, and a thickness dimension of 0.625 mm.
The sides of the first semiconductor chip and the second semiconductor chip having a vertical dimension of 45 mm are attached along the longitudinal direction of the first test piece.
The first semiconductor chip is attached to one end side in the longitudinal direction of the first test piece. The second semiconductor chip is attached to the other end side in the longitudinal direction of the first test piece. The distance between the first semiconductor chip and the second semiconductor chip attached to the first test piece is 35 μm.

In FIG. 3, the base material 10, the adhesive layer 20, and the first semiconductor chip CP1 on one end side of the second test piece are gripped by the first gripper 110 of the tensile tester, and the other of the second test piece is shown. It is a schematic diagram which shows the state which the base material 10, the pressure-sensitive adhesive layer 20 and the 2nd semiconductor chip CP2 on the end side are gripped by the 2nd gripping tool 120 of a tensile tester.

(Tensile strength)
In the pressure-sensitive adhesive sheet according to the present embodiment, the tensile strengths of the first test piece and the second test piece measured by using a tensile tester satisfy the relationship of the following mathematical formula (Equation 1A).
F _B1 / F _A1 ≤ 30 ... (Equation 1A)

In the above formula (Equation 1A), the tensile strength _FA1 is when the base material and the pressure-sensitive adhesive layer at both ends in the longitudinal direction of the first test piece are gripped with a gripper and pulled by a tensile tester by 0.5 mm. Strength.

In the above formula (Equation 1A), the tensile strength _FB1 is 0.5 mm by a tensile tester by grasping the base material, the pressure-sensitive adhesive layer and the semiconductor chip at both ends in the longitudinal direction of the second test piece with a gripper. It is the strength at the time of tension.

The present inventors have different behaviors of how the adhesive sheet extends when the adhesive sheet is expanded (expanded) between the portion where the semiconductor chip of the adhesive sheet is not attached and the portion where the semiconductor chip is attached. I found that. Further, in the conventional adhesive sheet, the present inventors have a large difference between the tensile strength of the portion of the adhesive sheet to which the semiconductor chip is not attached and the tensile strength of the portion to which the semiconductor chip is attached. It was also found that when the pressure-sensitive adhesive sheet is expanded in the expanding step to increase the distance between the semiconductor chips, the difference in the amount of elongation of the pressure-sensitive adhesive sheet in the in-plane direction is large.
According to the pressure-sensitive adhesive sheet according to the present embodiment, the _FB1 / _FA1 is 30 or less, the tensile strength of the portion of the adhesive sheet where the semiconductor chip is not attached, and the tensile strength of the portion where the semiconductor chip is attached. The ratio F _B1 / F _A1 to the strength is small. Therefore, according to the pressure-sensitive adhesive sheet according to the present embodiment, when the pressure-sensitive adhesive sheet is expanded in the expanding step to extend the distance between the semiconductor chips, the difference in the amount of elongation of the pressure-sensitive adhesive sheet in the in-plane direction becomes small. It has excellent expandability and can reduce variations in distance between semiconductor chips.
Incidentally, the amount of tension that 0.5mm in measuring the tensile strength _{F A1} and _{F B1} is one measure of the draw amount in expanding step. Therefore, the pressure-sensitive adhesive sheet according to the present embodiment may be used in an expanding step having a tensile amount smaller than 0.5 mm, or may be used in an expanding step having a tensile amount larger than 0.5 mm.
According to the pressure-sensitive adhesive sheet according to the present embodiment, since _F B1 _{/ F A1} when pulling 0.5mm is 30 or less, using a pressure-sensitive adhesive sheet according to the present embodiment expanding step to greatly stretched than 0.5mm At that time, it is possible to suppress an excessively large difference in the amount of elongation between the portion of the pressure-sensitive adhesive sheet to which the semiconductor chip is not attached and the tensile strength of the portion to which the semiconductor chip is attached.

PSA sheet according to the present embodiment, the tensile strength F _B1 tensile strength F _A1 and the second test piece of the first test piece was measured using a tensile tester, satisfies the following equation (Equation 1B) Is preferable.
1 ≤ F _B1 / F _A1 ≤ 30 ... (Equation 1B)

PSA sheet according to the present embodiment, the tensile strength F _B1 tensile strength F _A1 and the second test piece of the first test piece was measured using a tensile tester, satisfies the following equation (Equation 1C) It is also preferable.
F _B1 / F _A1 ≤ 20 ... (Equation 1C)

Wherein the value of F _B1 / _{F A1} formula (number 1A), as a method of adjusting the range of formula (number 1B) or a formula (number 1C), include the following method. For example, changing the composition of the pressure-sensitive adhesive composition used for the pressure-sensitive adhesive layer 20, changing the thickness of the pressure-sensitive adhesive layer, changing the material of the base material, changing the thickness of the base material, etc. by combining one or _more, F B1 _{/ F} equation value of _A1 (number 1A), can be adjusted within the range of equation (equation 1B) or a formula (number 1C).

(Young's modulus)
In the pressure-sensitive adhesive sheet according to the present embodiment, it is preferable that the Young's modulus Y _A1 of the first test piece and the Young's modulus Y _B1 of the second test piece satisfy the relationship of the following mathematical formula (Equation 2A).
Y _B1 / Y _A1 ≤ 19 ... (Equation 2A)
By satisfying the relationship of the above mathematical formula (Equation 2A), the ratio of the Young's modulus of the portion where the semiconductor chip of the adhesive sheet is not attached to the Young's modulus of the portion where the semiconductor chip is attached Y _B1 / Y _A1 Is small. Therefore, when the pressure-sensitive adhesive sheet is expanded in the expanding step to increase the distance between the semiconductor chips, it is easy to reduce the difference in the amount of elongation of the pressure-sensitive adhesive sheet in the in-plane direction. Further, by satisfying the relationship of the above mathematical formula (Equation 2A), it is possible to prevent the value of _{Y B1} / Y _{A1 from} becoming excessively large even if the adhesive sheet is used in the expanding step in which the tensile amount is larger than 0.5 mm. ..
The Young's modulus of the pressure-sensitive adhesive sheet can be measured according to the measuring method described in Examples described later.

(Base material)
The base material preferably has a first base material surface and a second base material surface opposite to the first base material surface. For example, as shown in FIG. 1, the base material 10 of the pressure-sensitive adhesive sheet 1 has a first base material surface 11 and a second base material surface 12 on the opposite side of the first base material surface 11.
In the pressure-sensitive adhesive sheet of the present embodiment, it is preferable that the pressure-sensitive adhesive layer according to the present embodiment is provided on one surface of the first base material surface and the second base material surface.

The material of the base material is preferably a thermoplastic elastomer or a rubber-based material, and more preferably a thermoplastic elastomer from the viewpoint of being easily stretched greatly.

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 thermoplastic elastomer may be used alone or in combination of two or more. As the thermoplastic elastomer, it is preferable to use a urethane-based elastomer from the viewpoint of being large and easy to stretch. That is, in the pressure-sensitive adhesive sheet according to the present embodiment, the base material preferably contains a urethane-based elastomer.

The base material may be a laminated film in which a plurality of films made of the above materials (for example, a thermoplastic elastomer or a rubber-based material) are laminated. Further, the base material may be a laminated film in which a film made of the above materials (for example, a thermoplastic elastomer or a rubber-based material) and another film are laminated.

The base material may contain an additive in a film containing the above resin-based material as a main material.
Examples of the additive include pigments, dyes, flame retardants, plasticizers, antistatic agents, lubricants, fillers and the like. Examples of the pigment include titanium dioxide, carbon black and the like. Examples of the filler include organic materials such as melamine resin, inorganic materials such as fumed silica, and metallic materials such as nickel particles. The content of such additives is not particularly limited, but it is preferable to keep the content within a range in which the base material can exhibit a desired function.

The substrate is surface-treated or primer on one or both sides, if desired, for the purpose of improving adhesion to the pressure-sensitive adhesive layer laminated on at least one of the first substrate surface and the second substrate surface. It may be treated. Examples of the surface treatment include an oxidation method and an unevenness method. Examples of the primer treatment include a method of forming a primer layer on the surface of the base material. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone treatment, ultraviolet irradiation treatment and the like. Examples of the unevenness method include a sandblasting method and a thermal spraying treatment method.

When the pressure-sensitive adhesive layer contains an energy ray-curable pressure-sensitive adhesive, the base material preferably has permeability to energy rays. When ultraviolet rays are used as energy rays, the base material preferably has transparency to ultraviolet rays. When an electron beam is used as the energy ray, the base material preferably has the transparency of the electron beam.

The thickness of the base material is not limited as long as the adhesive sheet can function properly in the desired process. The thickness of the base material is preferably 20 μm or more, and more preferably 40 μm or more. The thickness of the base material is preferably 250 μm or less, more preferably 200 μm or less.

Further, the standard deviation of the thickness of the base material is 2 μm or less when the thickness of a plurality of places is measured at intervals of 2 cm in the in-plane direction of the first base material surface or the second base material surface of the base material. It is preferably 1.5 μm or less, more preferably 1 μm or less. When the standard deviation is 2 μm or less, the pressure-sensitive adhesive sheet has a highly accurate thickness, and the pressure-sensitive adhesive sheet can be uniformly stretched.

The tensile elastic modulus in the MD direction and the CD direction of the base material at 23 ° C. is 10 MPa or more and 350 MPa or less, respectively, and the 100% stress in the MD direction and the CD direction of the base material at 23 ° C. is 3 MPa or more and 20 MPa or less, respectively. It is preferable to have.
When the tensile elastic modulus and 100% stress are in the above ranges, the pressure-sensitive adhesive sheet can be greatly stretched.
The 100% stress of the base material is a value obtained as follows. A test piece having a size of 100 mm (length direction) x 15 mm (width direction) is cut out from the base material. Grasp both ends of the cut out test piece in the length direction with a gripper so that the length between the grippers is 50 mm. After grasping the test piece with the gripping tool, the test piece is pulled in the length direction at a speed of 200 mm / min, and the measured value of the tensile force when the length between the gripping tools becomes 100 mm is read. The 100% stress of the base material is a value obtained by dividing the read measured value of the tensile force by the cross-sectional area of the base material. The cross-sectional area of the base material is calculated by the length in the width direction of 15 mm × the thickness of the base material (test piece). The cutting is performed so that the flow direction (MD direction) or the direction orthogonal to the MD direction (CD direction) at the time of manufacturing the base material coincides with the length direction of the test piece. In this tensile test, the thickness of the test piece is not particularly limited and may be the same as the thickness of the base material to be tested.

It is preferable that the elongation at break in the MD direction and the CD direction of the base material at 23 ° C. is 100% or more, respectively.
When the breaking elongation of the base material in the MD direction and the breaking elongation in the CD direction is 100% or more, the pressure-sensitive adhesive sheet can be greatly stretched without breaking.

The tensile elastic modulus (MPa) of the base material and the breaking elongation (%) of the base material can be measured as follows. The base material is cut into 15 mm × 140 mm to obtain a test piece. For the test piece, the elongation at break and the tensile elastic modulus at 23 ° C. are measured in accordance with JIS K7161: 2014 and JIS K7127: 1999. Specifically, the above test piece is pulled at a speed of 200 mm / min after setting the distance between chucks to 100 mm with a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph AG-IS 500N"). Perform the test and measure the elongation at break (%) and the tensile elastic modulus (MPa). The measurement is performed in both the flow direction (MD) at the time of manufacturing the base material and the direction perpendicular to the flow direction (CD).

(Adhesive layer)
In the pressure-sensitive adhesive sheet according to the present embodiment, the pressure-sensitive adhesive layer is not particularly limited as long as the relationship of the above-mentioned mathematical formula (Equation 1A) is satisfied. The materials constituting the pressure-sensitive adhesive layer can be appropriately selected and blended from, for example, the materials described below so as to satisfy the range of the relationship of the above-mentioned mathematical formula (Equation 1A).
For example, examples of the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer include rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, polyester-based pressure-sensitive adhesives, and urethane-based pressure-sensitive adhesives.

In the pressure-sensitive adhesive sheet according to the present embodiment, the pressure-sensitive adhesive layer preferably contains an acrylic pressure-sensitive adhesive.

-Energy ray curable resin (a1)
The pressure-sensitive adhesive layer preferably contains an energy ray-curable resin (a1). The energy ray-curable resin (a1) has an energy ray-curable double bond in the molecule.
The pressure-sensitive adhesive layer containing the energy ray-curable resin is cured by energy ray irradiation, and the adhesive strength is reduced. When it is desired to separate the adherend and the pressure-sensitive adhesive sheet, the pressure-sensitive adhesive layer can be easily separated by irradiating the pressure-sensitive adhesive layer with energy rays.

The energy ray-curable resin (a1) is preferably a (meth) acrylic resin.

The energy ray-curable resin (a1) is preferably an ultraviolet curable resin, and more preferably an ultraviolet curable (meth) acrylic resin.

The energy ray-curable resin (a1) is a resin that polymerizes and cures when irradiated with energy rays. Examples of the energy ray include ultraviolet rays and electron beams.
Examples of the energy ray-curable resin (a1) include low molecular weight compounds having an energy ray-polymerizable group (monofunctional monomer, polyfunctional monomer, monofunctional oligomer, and polyfunctional oligomer). Specifically, the energy ray-curable resin (a1) includes trimethyl propantriacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-. Butylene glycol diacrylate, acrylates such as 1,6-hexanediol diacrylate, cyclic aliphatic skeleton-containing acrylates such as dicyclopentadiene dimethoxydiacrylate and isobornyl acrylate, polyethylene glycol diacrylates, oligoester acrylates, urethane acrylate oligomers, Acrylate-based compounds such as epoxy-modified acrylates, polyether acrylates, and itaconic acid oligomers are used.

The molecular weight of the energy ray-curable resin (a1) is usually 100 or more and 30,000 or less, and preferably 300 or more and 10,000 or less.

-(Meta) acrylic copolymer (b1)
The pressure-sensitive adhesive layer according to the present embodiment preferably further contains a (meth) acrylic copolymer (b1). The (meth) acrylic copolymer is different from the energy ray-curable resin (a1) described above.

The (meth) acrylic copolymer (b1) preferably has an energy ray-curable carbon-carbon double bond. That is, in the present embodiment, the pressure-sensitive adhesive layer preferably contains an energy ray-curable resin (a1) and an energy ray-curable (meth) acrylic copolymer (b1).

The pressure-sensitive adhesive layer according to the present embodiment preferably contains the energy ray-curable resin (a1) in a proportion of 10 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic copolymer (b1). It is more preferably contained in a proportion of parts by mass or more, and further preferably contained in a proportion of 25% by mass or more.
The pressure-sensitive adhesive layer according to the present embodiment preferably contains the energy ray-curable resin (a1) in a proportion of 80 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic copolymer (b1). It is more preferably contained in a proportion of parts by mass or less, and further preferably contained in a proportion of 60 parts by mass or less.

The weight average molecular weight (Mw) of the (meth) acrylic copolymer (b1) is preferably 10,000 or more, more preferably 150,000 or more, and even more preferably 200,000 or more.
The weight average molecular weight (Mw) of the (meth) acrylic copolymer (b1) is preferably 1.5 million or less, more preferably 1 million or less.
The weight average molecular weight (Mw) in the present specification is a standard polystyrene-equivalent value measured by a gel permeation chromatography method (GPC method).

The (meth) acrylic copolymer (b1) is a (meth) acrylic acid ester polymer (b2) in which a functional group (energy ray-curable group) having energy ray curability is introduced into the side chain (hereinafter, "energy"). It may be referred to as "line curable polymer (b2)").

In the energy ray-curable polymer (b2), an acrylic copolymer (b21) having a functional group-containing monomer unit is reacted with an unsaturated group-containing compound (b22) having a functional group bonded to the functional group. It is preferable that the copolymer is obtained. In addition, in this specification, (meth) acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms.

The acrylic copolymer (b21) preferably contains a structural unit derived from a functional group-containing monomer and a structural unit derived from a (meth) acrylic acid ester monomer or a derivative of the (meth) acrylic acid ester monomer. ..

The functional group-containing monomer as a constituent unit of the acrylic copolymer (b21) is preferably a monomer having a polymerizable double bond and a functional group in the molecule. The functional group is preferably at least one functional group selected from the group consisting of a hydroxy group, a carboxy group, an amino group, a substituted amino group, an epoxy group and the like.

Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl ( Examples thereof include meta) acrylate and 4-hydroxybutyl (meth) acrylate. The hydroxy group-containing monomer may be used alone or in combination of two or more.

Examples of the carboxy group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. The carboxy group-containing monomer may be used alone or in combination of two or more.

Examples of the amino group-containing monomer or the substituted amino group-containing monomer include aminoethyl (meth) acrylate and n-butylaminoethyl (meth) acrylate. The amino group-containing monomer or the substituted amino group-containing monomer may be used alone or in combination of two or more.

The (meth) acrylic acid ester monomer constituting the acrylic copolymer (b21) includes an alkyl (meth) acrylate having an alkyl group having 1 or more and 20 or less carbon atoms, and for example, an alicyclic structure in the molecule. (Alicyclic structure-containing monomer) having the above is preferably used.

As the alkyl (meth) acrylate, an alkyl (meth) acrylate having an alkyl group having 1 or more and 18 or less carbon atoms is preferable. As the alkyl (meth) acrylate, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and the like are more preferable. Alkyl (meth) acrylates may be used alone or in combination of two or more.

Examples of the alicyclic structure-containing monomer include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate, isobornyl (meth) acrylate, and dicyclopentenyl (meth) acrylate. , And dicyclopentenyloxyethyl (meth) acrylate and the like are preferably used. The alicyclic structure-containing monomer may be used alone or in combination of two or more.

The acrylic copolymer (b21) preferably contains the structural unit derived from the functional group-containing monomer in a proportion of 1% by mass or more, and more preferably in a proportion of 5% by mass or more. It is more preferable to contain it in a proportion of mass% or more.
Further, the acrylic copolymer (b21) preferably contains the structural unit derived from the functional group-containing monomer in a proportion of 35% by mass or less, and more preferably in a proportion of 30% by mass or less. , 25% by mass or less is more preferable.

Further, the acrylic copolymer (b21) preferably contains a structural unit derived from the (meth) acrylic acid ester monomer or a derivative thereof in a proportion of 50% by mass or more, and preferably in a proportion of 60% by mass or more. It is more preferable that the content is 70% by mass or more.
Further, the acrylic copolymer (b21) preferably contains a structural unit derived from the (meth) acrylic acid ester monomer or a derivative thereof in a proportion of 99% by mass or less, and preferably in a proportion of 95% by mass or less. It is more preferable that the content is 90% by mass or less.

The acrylic copolymer (b21) can be obtained by copolymerizing a functional group-containing monomer as described above with a (meth) acrylic acid ester monomer or a derivative thereof by a conventional method.
The acrylic copolymer (b21) may contain at least one structural unit selected from the group consisting of dimethylacrylamide, vinyl formate, vinyl acetate, styrene and the like, in addition to the above-mentioned monomers. ..

By reacting the acrylic copolymer (b21) having the functional group-containing monomer unit with the unsaturated group-containing compound (b22) having a functional group bonded to the functional group, the energy ray-curable polymer (b2) ) Is obtained.

The functional group of the unsaturated group-containing compound (b22) can be appropriately selected depending on the type of functional group of the functional group-containing monomer unit of the acrylic copolymer (b21). For example, when the functional group of the acrylic copolymer (b21) is a hydroxy group, an amino group or a substituted amino group, the functional group of the unsaturated group-containing compound (b22) is preferably an isocyanate group or an epoxy group, and acrylic. When the functional group of the system copolymer (b21) is an epoxy group, the functional group of the unsaturated group-containing compound (b22) is preferably an amino group, a carboxy group or an aziridinyl group.

The unsaturated group-containing compound (b22) contains at least one energy ray-polymerizable carbon-carbon double bond in one molecule, preferably one or more and six or less, and preferably contains one or more and four or less. Is more preferable.

Examples of the unsaturated group-containing compound (b22) include 2-methacryloyloxyethyl isocyanate (2-isocyanatoethyl methacrylate), meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, and allyl isocyanate, 1,1 -(Bisocyanyloxymethyl) ethyl isocyanate; acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or polyisocyanate compound with hydroxyethyl (meth) acrylate; a diisocyanate compound or polyisocyanate compound, a polyol compound, and hydroxyethyl ( Acryloyl monoisocyanate compound obtained by reaction with meta) acrylate; glycidyl (meth) acrylate; (meth) acrylic acid, 2- (1-aziridinyl) ethyl (meth) acrylate, 2-vinyl-2-oxazoline, 2-iso Propenyl-2-oxazoline and the like can be mentioned.

The unsaturated group-containing compound (b22) is preferably used at a ratio (addition rate) of 50 mol% or more, preferably 60 mol%, based on the number of moles of the functional group-containing monomer of the acrylic copolymer (b21). It is more preferably used in the above ratio, and further preferably used in the ratio of 70 mol% or more.
The unsaturated group-containing compound (b22) is preferably used in a proportion of 95 mol% or less, preferably 93 mol% or less, based on the number of moles of the functional group-containing monomer of the acrylic copolymer (b21). It is more preferably used, and further preferably used in a proportion of 90 mol% or less.

In the reaction between the acrylic copolymer (b21) and the unsaturated group-containing compound (b22), the functional group of the acrylic copolymer (b21) and the functional group of the unsaturated group-containing compound (b22) are used. Depending on the combination, the reaction temperature, pressure, solvent, time, presence / absence of catalyst, and type of catalyst can be appropriately selected. As a result, the functional group of the acrylic copolymer (b21) reacts with the functional group of the unsaturated group-containing compound (b22), and the unsaturated group becomes a side chain of the acrylic copolymer (b21). Introduced to give the energy ray-curable polymer (b2).

The weight average molecular weight (Mw) of the energy ray-curable polymer (b2) is preferably 10,000 or more, more preferably 150,000 or more, and even more preferably 200,000 or more.
The weight average molecular weight (Mw) of the energy ray-curable polymer (b2) is preferably 1.5 million or less, more preferably 1 million or less.

-Photopolymerization initiator (C)
When the pressure-sensitive adhesive layer contains a UV-curable compound (for example, a UV-curable resin), the pressure-sensitive adhesive layer preferably contains a photopolymerization initiator (C).
Since the pressure-sensitive adhesive layer contains the photopolymerization initiator (C), the polymerization curing time and the amount of light irradiation can be reduced.

Specific examples of the photopolymerization initiator (C) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, and benzoin dimethyl ketal. 2,4-Diethylthioxanthone, 1-hydroxycyclohexylphenylketone, benzyldiphenylsulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloranthraquinone, (2,4) 6-trimethylbenzyldiphenyl) phosphine oxide, 2-benzothiazole-N, N-diethyldithiocarbamate, oligo {2-hydroxy-2-methyl-1- [4- (1-propenyl) phenyl] propanone}, and 2 , 2-Dimethoxy-1,2-diphenylethane-1-one and the like. These may be used alone or in combination of two or more.

When the energy ray-curable resin (a1) and the (meth) acrylic copolymer (b1) are blended in the pressure-sensitive adhesive layer, the photopolymerization initiator (C) is an energy ray-curable resin (a1). The total amount of the (meth) acrylic copolymer (b1) is preferably 0.1 parts by mass or more, and more preferably 0.5 parts by mass or more. preferable.
Further, the photopolymerization initiator (C) is an energy ray-curable resin (a1) when the energy ray-curable resin (a1) and the (meth) acrylic copolymer (b1) are blended in the pressure-sensitive adhesive layer. ) And the (meth) acrylic copolymer (b1) in an amount of 10 parts by mass or less, more preferably 6 parts by mass or less, based on 100 parts by mass of the total amount.

The pressure-sensitive adhesive layer may contain other components as appropriate in addition to the above components. Examples of other components include a cross-linking agent (E) and the like.

・ Crosslinking agent (E)
As the cross-linking agent (E), a polyfunctional compound having reactivity with a functional group of the (meth) acrylic copolymer (b1) or the like can be used. Examples of such polyfunctional compounds include isocyanate compounds, epoxy compounds, amine compounds, melamine compounds, aziridine compounds, hydrazine compounds, aldehyde compounds, oxazoline compounds, metal alkoxide compounds, metal chelate compounds, metal salts, ammonium salts, etc. And reactive phenolic resins and the like.

The blending amount of the cross-linking agent (E) is preferably 0.01 part by mass or more, and preferably 0.03 part by mass or more with respect to 100 parts by mass of the (meth) acrylic copolymer (b1). More preferably, it is 0.04 parts by mass or more.
The amount of the cross-linking agent (E) to be blended is preferably 8 parts by mass or less, and more preferably 5 parts by mass or less, based on 100 parts by mass of the (meth) acrylic copolymer (b1). , 3.5 parts by mass or less is more preferable.

The thickness of the adhesive layer is not particularly limited. The thickness of the pressure-sensitive adhesive layer is, for example, preferably 10 μm or more, and more preferably 20 μm or more. The thickness of the pressure-sensitive adhesive layer is preferably 150 μm or less, and more preferably 100 μm or less.

(Release sheet)
The adhesive sheet according to the present embodiment may have a release sheet laminated on the adhesive surface for the purpose of protecting the adhesive surface until the adhesive surface is attached to an adherend (for example, a semiconductor chip or the like). .. The structure of the release sheet is arbitrary. Examples of the release sheet include a plastic film that has been peeled off with a release agent or the like.
Specific examples of the plastic film include a polyester film and a polyolefin film. Examples of the polyester film include films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of the polyolefin film include a film such as polypropylene or polyethylene.
As the release agent, silicone-based, fluorine-based, long-chain alkyl-based, and the like can be used. Among these release agents, a silicone type that can obtain stable performance at low cost is preferable.
The thickness of the release sheet is not particularly limited. The thickness of the release sheet is usually 20 μm or more and 250 μm or less.

[Manufacturing method of adhesive sheet]
The pressure-sensitive adhesive sheet according to this embodiment can be manufactured in the same manner as the conventional pressure-sensitive adhesive sheet.
The method for producing the pressure-sensitive adhesive sheet is not particularly limited as long as the above-mentioned pressure-sensitive adhesive layer can be laminated on one surface of the base material.
The following methods can be mentioned as an example of the method for manufacturing the adhesive sheet. First, a pressure-sensitive composition constituting the pressure-sensitive adhesive layer and, if desired, a coating liquid further containing a solvent or a dispersion medium are prepared. Next, the coating liquid is applied onto one surface of the base material by the coating means to form a coating film. Examples of the coating means include a die coater, a curtain coater, a spray coater, a slit coater, a knife coater and the like. Next, the pressure-sensitive adhesive layer can be formed by drying the coating film. The properties of the coating liquid are not particularly limited as long as it can be applied. The coating liquid may contain a component for forming the pressure-sensitive adhesive layer as a solute, or may contain a component for forming the pressure-sensitive adhesive layer as a dispersoid.

Further, as another example of the method for manufacturing the adhesive sheet, the following method can be mentioned. First, a coating liquid is applied on the peeled surface of the above-mentioned peeling sheet to form a coating film. Next, the coating film is dried to form a laminate composed of an adhesive layer and a release sheet. Next, a base material may be attached to the surface of the pressure-sensitive adhesive layer of the laminated body opposite to the surface on the release sheet side to obtain a laminate of the pressure-sensitive adhesive sheet and the release sheet. The release sheet in this laminate may be peeled off as a process material, or protects the pressure-sensitive adhesive layer until an adherend (for example, a semiconductor chip, a semiconductor wafer, etc.) is attached to the pressure-sensitive adhesive layer. May be good.

When the coating liquid contains a cross-linking agent, it is possible to change the drying conditions (for example, temperature, time, etc.) of the coating film, or by separately performing a heat treatment (meta) in the coating film. ) The cross-linking reaction between the acrylic copolymer (b1) and the cross-linking agent may be allowed to proceed to form a cross-linked structure in the pressure-sensitive adhesive layer at a desired abundance density. In order to allow this cross-linking reaction to proceed sufficiently, after laminating the pressure-sensitive adhesive layer on the base material by the above-mentioned method or the like, the obtained pressure-sensitive adhesive sheet is allowed to stand in an environment of, for example, 23 ° C. and a relative humidity of 50% for several days. You may perform curing such as placing.

The thickness of the pressure-sensitive adhesive sheet according to this embodiment is preferably 30 μm or more, and more preferably 50 μm or more. The thickness of the pressure-sensitive adhesive sheet is preferably 400 μm or less, and more preferably 300 μm or less.

[How to use the adhesive sheet]
Since the pressure-sensitive adhesive sheet according to the present embodiment can be attached to various adherends, the adherend to which the pressure-sensitive adhesive sheet according to the present embodiment can be applied is not particularly limited. For example, the adherend is preferably a semiconductor chip and a semiconductor wafer.

The pressure-sensitive adhesive sheet according to this embodiment can be used, for example, for semiconductor processing.
During the manufacturing process of a semiconductor device, it is preferably used in an expanding process for expanding the distance between a plurality of semiconductor chips.
The plurality of semiconductor chips are preferably attached to the central portion of the pressure-sensitive adhesive sheet.
Further, the plurality of semiconductor chips are preferably semiconductor chips obtained by dicing a semiconductor wafer. For example, the semiconductor wafer attached to the dicing sheet may be diced, divided into a plurality of semiconductor chips, and the plurality of semiconductor chips obtained by the division may be directly transferred to the adhesive sheet according to the present embodiment. Then, it may be transferred to another pressure-sensitive adhesive sheet and then transferred from the other pressure-sensitive adhesive sheet to the pressure-sensitive adhesive sheet according to the present embodiment.

The expansion interval of a plurality of semiconductor chips depends on the size of the semiconductor chips, and is not particularly limited. The pressure-sensitive adhesive sheet according to the present embodiment is preferably used to widen the distance between adjacent semiconductor chips in a plurality of semiconductor chips attached to one side of the pressure-sensitive adhesive sheet by 200 μm or more. The upper limit of the distance between the semiconductor chips is not particularly limited. The upper limit of the distance between the semiconductor chips may be, for example, 6000 μm.

Further, the pressure-sensitive adhesive sheet according to the present embodiment can also be used when the distance between a plurality of semiconductor chips laminated on one side of the pressure-sensitive adhesive sheet is widened by at least biaxial stretching. In this case, the adhesive sheet is stretched by applying tension in four directions of + X-axis direction, -X-axis direction, + Y-axis direction, and -Y-axis direction, for example, in the X-axis and Y-axis orthogonal to each other. More specifically, it is stretched in the MD direction and the CD direction of the base material, respectively.

Biaxial stretching as described above can be performed using, for example, a separation device that applies tension in the X-axis direction and the Y-axis direction. Here, it is assumed that the X-axis and the Y-axis are orthogonal to each other, one of the directions parallel to the X-axis is the + X-axis direction, the direction opposite to the + X-axis direction is the -X-axis direction, and the direction parallel to the Y-axis. One of them is defined as the + Y-axis direction, and the direction opposite to the + Y-axis direction is defined as the −Y-axis direction.

The separating device applies tension to the adhesive sheet in four directions of + X-axis direction, -X-axis direction, + Y-axis direction, and -Y-axis direction, and with a plurality of holding means in each of the four directions. , It is preferable to provide a plurality of tension applying means corresponding to them. The number of holding means and tension applying means in each direction depends on the size of the pressure-sensitive adhesive sheet, but may be, for example, about 3 or more and 10 or less.

Here, for example, in a group including a plurality of holding means and a plurality of tension applying means provided for applying tension in the + X axis direction, each holding means includes a holding member for holding the adhesive sheet. It is preferable that each tension applying means applies tension to the pressure-sensitive adhesive sheet by moving the holding member corresponding to the tension applying means in the + X-axis direction. Then, it is preferable that the plurality of tension applying means are independently provided so as to move the holding means in the + X axis direction. Further, the same configuration is also applied to three groups including a plurality of holding means and a plurality of tension applying means provided for applying tension in the −X axis direction, the + Y axis direction, and the −Y axis direction, respectively. It is preferable to have. As a result, the separation device can apply a different magnitude of tension to the pressure-sensitive adhesive sheet for each region in the direction orthogonal to each direction.

Generally, when the pressure-sensitive adhesive sheet is held from four directions of + X-axis direction, -X-axis direction, + Y-axis direction and -Y-axis direction by using four holding members and stretched in the four directions, the pressure-sensitive adhesive sheet is formed. In addition to these four directions, these composite directions (for example, the composite direction of the + X-axis direction and the + Y-axis direction, the composite direction of the + Y-axis direction and the -X-axis direction, and the composite of the -X-axis direction and the -Y-axis direction). Tension is also applied in the direction and the combined direction of the −Y axis direction and the + X axis direction). As a result, there may be a difference between the distance between the semiconductor chips in the inner region of the pressure-sensitive adhesive sheet and the distance between the semiconductor chips in the outer region.

However, in the separation device described above, a plurality of tension applying means can independently apply tension to the pressure-sensitive adhesive sheet in each of the + X-axis direction, the −X-axis direction, the + Y-axis direction, and the −Y-axis direction. Therefore, the pressure-sensitive adhesive sheet can be stretched so that the difference in the distance between the inside and the outside of the pressure-sensitive adhesive sheet as described above is eliminated.
As a result, the distance between the semiconductor chips can be adjusted accurately.

It is preferable that the separation device further includes a measuring means for measuring the mutual distance between the semiconductor chips. Here, it is preferable that the tension applying means is provided so that a plurality of holding members can be individually moved based on the measurement results of the measuring means. When the separation device is provided with the measuring means, the distance can be further adjusted based on the measurement result of the distance between the semiconductor chips by the measuring means, and as a result, the distance between the semiconductor chips can be adjusted more accurately. Is possible.

In the separation device, examples of the holding means include a chucking means and a depressurizing means. Examples of the chucking means include a mechanical chuck and a chuck cylinder. Examples of the decompression means include a decompression pump, a vacuum ejector, and the like. Further, in the separation device, the holding means may be configured to support the pressure-sensitive adhesive sheet with an adhesive, a magnetic force, or the like. Further, as the holding member in the chuck means, for example, a lower support member that supports the adhesive sheet from below, a drive device that is supported by the lower support member, and a drive device that is supported by the output shaft of the drive device to drive the drive device. A holding member having a structure including an upper support member capable of pressing the adhesive sheet from above can be used. Examples of the drive device include an electric device, an actuator, and the like. Examples of the electric device include a rotary motor, a linear motor, a linear motor, a single-axis robot, an articulated robot, and the like. Examples of the actuator include an air cylinder, a hydraulic cylinder, a rodless cylinder, a rotary cylinder, and the like.

Further, in the separation device, the tension applying means may include a drive device, and the holding member may be moved by the drive device. As the drive device included in the tension applying means, the same drive device as the drive device included in the holding member described above can be used. For example, the tension applying means includes a linear motor as a drive device and an output shaft interposed between the linear motor and the holding member, and the driven linear motor moves the holding member via the output shaft. It may be a configuration.

When the distance between the semiconductor chips is widened by using the adhesive sheet according to the present embodiment, the distance may be widened from the state where the semiconductor chips are in contact with each other or the distance between the semiconductor chips is hardly widened, or the semiconductor. The distance between the chips may be further increased from the state in which the distance between the chips has already been increased to a predetermined distance.

When the distance between the semiconductor chips is increased from the state where the semiconductor chips are in contact with each other or the distance between the semiconductor chips is hardly widened, for example, after obtaining a plurality of semiconductor chips by dividing the semiconductor wafer on a dicing sheet. , A plurality of semiconductor chips can be transferred from the dicing sheet to the pressure-sensitive adhesive sheet according to the present embodiment, and subsequently, the distance between the semiconductor chips can be widened. Alternatively, after the semiconductor wafer is divided on the pressure-sensitive adhesive sheet according to the present embodiment to obtain a plurality of semiconductor chips, the distance between the semiconductor chips can be widened.

When the distance between the semiconductor chips has already been widened to a predetermined distance and the distance is further widened, another pressure-sensitive adhesive sheet, preferably the pressure-sensitive adhesive sheet according to the present embodiment (first stretching pressure-sensitive adhesive sheet) is used. After expanding the distance between the semiconductor chips to a predetermined distance, the semiconductor chips are transferred from the sheet (adhesive sheet for first stretching) to the adhesive sheet (adhesive sheet for second stretching) according to the present embodiment, and subsequently. By stretching the pressure-sensitive adhesive sheet (the pressure-sensitive adhesive sheet for second stretching) according to the present embodiment, the distance between the semiconductor chips can be further increased. The transfer of the semiconductor chip and the stretching of the pressure-sensitive adhesive sheet may be repeated a plurality of times until the distance between the semiconductor chips reaches a desired distance.

[Second Embodiment]
[Adhesive sheet]
The pressure-sensitive adhesive sheet according to the present embodiment has a base material and a pressure-sensitive adhesive layer like the pressure-sensitive adhesive sheet according to the first embodiment.
The pressure-sensitive adhesive layer according to the present embodiment contains an energy ray-curable resin, a cured portion where the energy ray-curable resin is cured at both ends in the width direction of the pressure-sensitive adhesive layer, and a cured portion where the energy ray-curable resin is cured. It differs from the pressure-sensitive adhesive sheet according to the first embodiment in that it has an uncured portion that has not been cured.
In the pressure-sensitive adhesive sheet according to the present embodiment, the ratio of the tensile strength of the first test piece and the second test piece prepared from the uncured portion of the pressure-sensitive adhesive sheet measured by a tensile tester satisfies a predetermined range.
In the following description, the parts related to the differences from the first embodiment will be mainly described, and the overlapping description will be omitted or simplified. The same reference numerals are given to the same configurations as those in the first embodiment, and the description thereof will be omitted or simplified.

The pressure-sensitive adhesive sheet according to this embodiment also has a base material and a pressure-sensitive adhesive layer. The shape of the adhesive sheet can be any shape such as a tape shape (long form) and a label shape (single leaf shape).

FIG. 4 shows a schematic cross-sectional view of the pressure-sensitive adhesive sheet 1A according to the present embodiment.
The pressure-sensitive adhesive sheet 1A has a base material 10 and a pressure-sensitive adhesive layer 20. The pressure-sensitive adhesive layer 20 contains an energy ray-curable resin. The pressure-sensitive adhesive layer 20 has a cured portion 22 in which the energy ray-curable resin is cured and an uncured portion 21 in which the energy ray-curable resin is not cured. As shown in FIG. 4, the cured portions 22 are formed at both ends in the width direction of the pressure-sensitive adhesive layer 20 of the pressure-sensitive adhesive sheet 1A. There is an uncured portion 21 between the cured portion 22 on one end side in the width direction and the cured portion 22 on the other end side.

The two sides of the pressure-sensitive adhesive sheet 1A facing each other in the width direction are cured by energy rays, and the cured portions 22 are formed at both ends in the width direction of the pressure-sensitive adhesive sheet 1A. Suppresses oozing out from the widthwise end of the adhesive sheet 1A to the outside of the sheet.

The cross-sectional shape of the cured portion 22 is rectangular in FIG. 4, but is not limited to a rectangular shape, and is not particularly limited as long as it can suppress the exudation of the adhesive.

It is preferable that the cured portion 22 is continuously formed along both ends in the width direction of the pressure-sensitive adhesive sheet 1A. Since the cured portion 22 is continuously formed in the longitudinal direction of the pressure-sensitive adhesive sheet 1A, it is easier to prevent the adhesive from seeping out from the end portion in the width direction of the sheet from the uncured portion 21. If the cured portion 22 is formed discontinuously, the adhesive may seep out from the portion where the cured portion 22 is not formed.

When the adhesive sheet 1A is a long sheet, it is preferable that the cured portion 22 is continuously formed in the longitudinal direction of the adhesive sheet 1A. Since the cured portion 22 is continuously formed in the longitudinal direction of the pressure-sensitive adhesive sheet 1A, it is easier to prevent the adhesive from seeping out from the end portion in the width direction of the sheet from the uncured portion 21.

FIG. 5 shows a schematic perspective view showing a long adhesive sheet 1A wound in a roll shape. Note that FIG. 5 shows a state in which the adhesive sheet 1A is partially extended from the roll.
As shown in FIG. 5, cured portions 22 are formed at both ends in the width direction of the pressure-sensitive adhesive sheet 1A, and are uncured between the cured portions 22 on one end side in the width direction and the cured portions 22 on the other end side. There is a part 21. Each of the cured portions 22 is continuously formed in the longitudinal direction of the pressure-sensitive adhesive sheet 1A. The roll on which the long adhesive sheet 1A as shown in FIG. 5 is wound is often stored so that the width direction of the roll is perpendicular to the mounting surface. Therefore, since the cured portions 22 are continuously formed at both ends of the pressure-sensitive adhesive sheet 1A in the width direction, it is easy to suppress the seepage of the adhesive from the uncured portions 21 during roll storage.

The width of the cured portion 22 is preferably 0.5 mm or more independently of each other. When the width of the cured portion 22 is 0.5 mm or more, it is easier to prevent the adhesive from seeping out from the sheet width direction end portion from the uncured portion 21 to the outside of the sheet. When the cured portion 22 is continuously formed along the end portion in the width direction, the width of the cured portion 22 does not have to be constant in the longitudinal direction, and is 0.5 mm or more in the longitudinal direction. It is preferably formed with the width of.
The width of the cured portion 22 is preferably 10 mm or less independently of each other. When the cured portion 22 is continuously formed along the end portion in the width direction, the width of the cured portion 22 is preferably formed to be 10 mm or less in the longitudinal direction.
If the width of the cured portion 22 is large, it becomes easier to suppress the seepage of the adhesive, but since the area of the uncured portion 21 becomes narrow, the effect of suppressing the seepage of the adhesive and the adhesion as an adhesive sheet are obtained. From the viewpoint of securing the area of the uncured portion 21 having the force, it is preferable to set the upper limit of the width of the cured portion 22.

(First test piece)
The first test piece is produced from the region of the uncured portion 21 of the pressure-sensitive adhesive sheet 1A according to the present embodiment. The width of the first test piece is 25 mm.
The state in which the first test piece is gripped in this embodiment is the same as in FIG. 2 shown in the first embodiment. The base material 10 on one end side of the first test piece and the uncured portion 21 of the adhesive layer 20 are gripped by the first gripper 110 of the tensile tester, and the base material 10 on the other end side of the first test piece. And the uncured portion 21 of the pressure-sensitive adhesive layer 20 is gripped by the second gripper 120 of the tensile tester.

(Second test piece)
The second test piece is produced by attaching two semiconductor chips to the first test piece produced from the pressure-sensitive adhesive sheet 1A according to the present embodiment. In the present embodiment, the two semiconductor chips are a first semiconductor chip and a second semiconductor chip. Both the first semiconductor chip and the second semiconductor chip have a vertical dimension of 45 mm, a horizontal dimension of 35 mm, and a thickness dimension of 0.625 mm.
The sides of the first semiconductor chip and the second semiconductor chip having a vertical dimension of 45 mm are attached along the longitudinal direction of the first test piece.
The first semiconductor chip is attached to one end side in the longitudinal direction of the first test piece. The second semiconductor chip is attached to the other end side in the longitudinal direction of the first test piece. The distance between the first semiconductor chip and the second semiconductor chip attached to the first test piece is 35 μm.

The state in which the second test piece is gripped in this embodiment is the same as in FIG. 3 shown in the first embodiment. The base material 10 on one end side of the second test piece, the uncured portion 21 of the adhesive layer 20, and the first semiconductor chip CP1 are gripped by the first gripper 110 of the tensile tester, and the second test piece is subjected to. The base material 10, the uncured portion 21 of the adhesive layer 20, and the second semiconductor chip CP2 on the other end side are gripped by the second gripper 120 of the tensile tester.

(Tensile strength)
In the pressure-sensitive adhesive sheet 1A according to the present embodiment, the tensile strengths of the first test piece and the second test piece measured using the tensile tester satisfy the relationship of the following mathematical formula (Equation 1A).
F _B1 / F _A1 ≤ 30 ... (Equation 1A)

A third test piece was prepared by cutting out the pressure-sensitive adhesive sheet 1A into a size of 150 mm in length and 25 mm in width along the elongated direction of the pressure-sensitive adhesive sheet 1A so as to include the cured portion 22 in which the energy ray-curable resin was cured. When the test piece of No. 1 was grasped by a pair of chucks with a chuck-to-chuck distance of 100 mm and extended to a chuck-to-chuck distance of 200 mm at a speed of 5 mm / sec, no floating occurred at the interface between the cured portion 22 and the base material 10. Is preferable.
When the cured portion of the pressure-sensitive adhesive sheet is stretched (for example, when the pressure-sensitive adhesive sheet is expanded), if a float occurs at the interface between the cured portion and the base material, the lifted cured portion breaks from the pressure-sensitive adhesive layer and the broken cured portion is broken. There is a risk that the part will scatter and adhere to the adherend and expanding device attached to the adhesive sheet and contaminate it. However, the pressure-sensitive adhesive sheet 1A according to the present embodiment does not float at the interface between the cured portion 22 and the base material 10 in the tensile test using the third test piece, and therefore is based on the broken cured portion as described above. It is easy to suppress contamination of the adherend and the expanding device. In order to prevent floating from occurring at the interface between the cured portion 22 and the base material 10, for example, a method of controlling the degree of curing of the energy ray-curable resin can be mentioned.

The adhesive sheet 1A according to the present embodiment has a first direction, a second direction opposite to the first direction, a third direction perpendicular to the first direction, and the third direction. When the area ratio (S2 / S1) × 100 of the area S1 of the pressure-sensitive adhesive sheet 1A before stretching and the area S2 of the pressure-sensitive adhesive sheet 1A after stretching is 381% after being stretched in the fourth direction, which is the opposite direction. It is preferable that the cured portion 22 of the pressure-sensitive adhesive layer 20 does not peel off at the interface with the base material 10.
The first direction, the second direction, the third direction, and the fourth direction correspond to, for example, the four directions of the biaxial stretching + X-axis direction, -X-axis direction, + Y-axis direction, and -Y-axis direction, which will be described later, respectively. It is preferable to do so. Examples of the device for extending in four directions include an expanding device described later.
The pressure-sensitive adhesive sheet 1A according to the present embodiment is stretched in four directions, and when the area ratio (S2 / S1) × 100 before and after stretching is 381%, the cured portion 22 of the pressure-sensitive adhesive layer 20 is with the base material 10. Since it does not peel off at the interface, even if the adhesive sheet 1A is used in the expanding step having a high elongation rate, it is easy to suppress contamination of the adherend and the expanding device due to the broken hardened portion.

[Manufacturing method of adhesive sheet]
The method for producing the pressure-sensitive adhesive sheet 1A according to the present embodiment includes the following steps (P1) to (P3).
(P1) A step of applying a pressure-sensitive adhesive composition containing an energy ray-curable resin onto a base material 10 to form a pressure-sensitive adhesive layer 20.
(P2) A step of irradiating both ends of the pressure-sensitive adhesive layer 20 in the width direction with energy rays UV to cure the energy ray-curable resin to form a cured portion 22.
(P3) From the cured portion 22 by leaving the entire cured portion 22 outside the widthwise both ends of the uncured portion 21 in which the energy ray-curable resin is not cured, or leaving a part of the cured portion 22. The process of cutting the outside.

The pressure-sensitive adhesive sheet 1A according to the present embodiment can be manufactured, for example, as follows.
First, as a step (P1), the pressure-sensitive adhesive layer 20 is formed on the base material 10. In the present embodiment, the pressure-sensitive adhesive layer 20 can be formed, for example, in the same manner as in the first embodiment.

FIG. 6A is a schematic cross-sectional view illustrating a step (P2) of forming the cured portions 22 at both ends in the width direction of the pressure-sensitive adhesive sheet 1A.
Since the pressure-sensitive adhesive layer 20 contains an energy ray-curable resin, both ends in the width direction are irradiated with energy rays UV to form a cured portion 22. When the energy ray-curable resin is an ultraviolet curable resin, it is irradiated with ultraviolet rays as energy rays.
The cured portion 22 is preferably formed with a width larger than the width of the cured portion 22 required for use as the pressure-sensitive adhesive sheet 1A.

FIG. 6B is a schematic cross-sectional view illustrating a step (P3) of irradiating energy rays to form the cured portion 22 and then cutting both ends of the pressure-sensitive adhesive sheet 1A in the width direction so that the cured portion 22 remains.
In FIG. 6B, cuts are made at positions C1 and C2 of the cured portion 22 formed with a width larger than the width required for use as the pressure-sensitive adhesive sheet 1A. By making a notch in the hardened portion 22 and cutting, it is possible to prevent the adhesive from adhering to the cutting blade. The cut is made along the sheet longitudinal direction of the hardened portion 22.
The width of the cured portion 22 (the distance from the boundary between the uncured portion 21 and the cured portion 22 to the position C1 or C2 in cross-sectional view) left outside the both ends in the width direction of the uncured portion 21 is independent of each other. , 0.5 mm or more is preferable.

FIG. 6C shows an adhesive sheet 1A in which hardened portions 22 are formed at both ends in the width direction after cutting by the step (P3), and scraps 1a.

After the step (P3) of cutting the outside of the cured portion 22, it is preferable to further have a step of winding the cut adhesive sheet 1A into a roll shape.

[How to use the adhesive sheet]
The pressure-sensitive adhesive sheet 1A according to the present embodiment can also be applied to the same usage method as the pressure-sensitive adhesive sheet according to the first embodiment.

The pressure-sensitive adhesive sheet 1A according to this embodiment can be used, for example, for semiconductor processing. The pressure-sensitive adhesive sheet 1A is preferably used in an expanding step for expanding the distance between a plurality of semiconductor chips during the manufacturing process of the semiconductor device.
The plurality of semiconductor chips are preferably attached to the central portion (uncured portion 21) of the pressure-sensitive adhesive sheet 1A.
In the expanding step, it is preferable to hold the cured portion 22 of the pressure-sensitive adhesive sheet 1A by the holding means of the separating device.

The pressure-sensitive adhesive sheet 1A according to the present embodiment stretches in the in-plane direction of the pressure-sensitive adhesive sheet when the pressure-sensitive adhesive is suppressed from seeping out and the pressure-sensitive adhesive sheet is expanded in the expanding step to extend the distance between semiconductor chips. The difference in quantity can be reduced, and it has excellent expandability.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment. The present invention includes aspects obtained by modifying the above-described embodiment to the extent that the object of the present invention can be achieved.

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples.

(Making an adhesive sheet)
[Example 1]
An acrylic copolymer was obtained by copolymerizing 62 parts by mass of butyl acrylate (BA), 10 parts by mass of methyl methacrylate (MMA), and 28 parts by mass of 2-hydroxyethyl acrylate (2HEA). A solution of a resin (acrylic A) to which 2-isocyanate ethyl methacrylate (manufactured by Showa Denko KK, product name "Karenzu MOI" (registered trademark)) is added to this acrylic copolymer (adhesive main agent, solid). Minutes 35.0% by mass) were prepared. The addition rate was 80 mol% of 2-isocyanate ethyl methacrylate with respect to 100 mol% of 2HEA of the acrylic copolymer.
The weight average molecular weight (Mw) of the obtained resin (acrylic A) was 90,000, and Mw / Mn was 4.5. The weight average molecular weight Mw and the number average molecular weight Mn in terms of standard polystyrene were measured by gel permeation chromatography (GPC) method, and the molecular weight distribution (Mw / Mn) was obtained from each measured value.
This pressure-sensitive adhesive main agent contains UV resin A (10-functional urethane acrylate, manufactured by Nippon Polyurethane Industry Co., Ltd., product name "UV-5806", Mw = 1740, including photopolymerization initiator), and a bird as a cross-linking agent. A range isocyanate-based cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., product name "Coronate L") was added. 50 parts by mass of UV resin A was added and 0.2 parts by mass of a cross-linking agent was added with respect to 100 parts by mass of the solid content in the pressure-sensitive adhesive main agent. After the addition, the pressure-sensitive adhesive composition A1 was prepared by stirring for 30 minutes.
Next, the prepared solution of the pressure-sensitive adhesive composition A1 was applied to a polyethylene terephthalate (PET) -based release film (manufactured by Lintec Corporation, product name "SP-PET38131", thickness 38 μm), dried, and adhered to a thickness of 40 μm. The agent layer was formed on the release film.
A polyester polyurethane elastomer sheet (manufactured by Seadam Co., Ltd., product name "Higres DUS202", thickness 100 μm) as a base material is attached to the pressure-sensitive adhesive layer, and then unnecessary portions at the ends in the width direction are cut and removed. To prepare an adhesive sheet.

[Example 2]
An acrylic copolymer was obtained by copolymerizing 52 parts by mass of butyl acrylate (BA), 20 parts by mass of methyl methacrylate (MMA), and 28 parts by mass of 2-hydroxyethyl acrylate (2HEA). A solution (adhesive main agent) of a resin (acrylic A2) to which 2-isocyanate ethyl methacrylate (manufactured by Showa Denko KK, product name "Karenzu MOI" (registered trademark)) is added to this acrylic copolymer. Prepared. The addition rate was 90 mol% of 2-isocyanate ethyl methacrylate with respect to 100 mol% of 2HEA of the acrylic copolymer.
The weight average molecular weight (Mw) of the obtained resin (acrylic A2) was 600,000, and Mw / Mn was 4.5. The weight average molecular weight Mw and the number average molecular weight Mn in terms of standard polystyrene were measured by gel permeation chromatography (GPC) method, and the molecular weight distribution (Mw / Mn) was obtained from each measured value.
Energy ray curable resin A (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., product name "SA-TE60"), photopolymerization initiator (manufactured by IGM Resins BV, product name "Omnirad 127D") and A cross-linking agent (TMP-TDI (trimethylol propan adduct of tolylene diisocyanate) manufactured by Toyochem Co., Ltd.) was added. 18 parts by mass of energy ray curable resin A with respect to 100 parts by mass of solid content in the adhesive main agent. Add 1.3 parts by mass of photopolymerization initiator, 0.2 parts by mass of cross-linking agent, add ethyl acetate, and then stir for 30 minutes to obtain a pressure-sensitive adhesive having a solid content of 35.0% by mass. Composition A1 was prepared.
Next, the prepared solution of the pressure-sensitive adhesive composition A1 was applied to a polyethylene terephthalate (PET) -based release film (manufactured by Lintec Corporation, product name "PET752150"), the coating film was dried at 90 ° C. for 90 seconds, and further 100. Drying at ° C. for 90 seconds formed a 30 μm thick pressure-sensitive adhesive layer on the release film.
A urethane base material (manufactured by Kurabo Industries Ltd., product name "U-1490", thickness 100 μm, hardness 90 degrees (A type)) was bonded to the pressure-sensitive adhesive layer to prepare an pressure-sensitive adhesive tape.
When cutting this adhesive tape to a width of 300 mm, two LED-UV units were installed at one cutting portion so as to straddle the cutting portion. The distance between the tip of the lens of the LED-UV unit and the tape was 10 mm. Regarding the output of the LED-UV unit, both lamps were irradiated with UV at an output of 50% to form a cured portion in the adhesive layer. The adhesive tape was cut along the formed cured portion to prepare an adhesive sheet (width 300 mm) having cured portions at both ends in the width direction. As shown in Table 2, the widths of the cured portions at both ends in the sheet width direction were set to 1.00 mm, respectively. The speed of the slit at the time of cutting was set to 10 m / min. Table 2 shows the relationship between the output of the LED-UV unit and the amount of light and illuminance per LED-UV unit.

The description of the LED-UV unit used in Example 2 is as follows.
・ LED-UV unit HOYA CANDEO OPTRONICS control unit = H-1 VC II
Light emitting part = H-1 VH4
Lens = HO-03L

[Example 3]
As for the adhesive sheet of Example 3, the output of the LED-UV unit in the production of the adhesive sheet according to Example 2 was changed to 40%, and the widths of the cured portions at both ends in the sheet width direction are shown in Table 2. It was produced in the same manner as in Example 2 except that each was set to 0.50 mm.

[Example 4]
As for the adhesive sheet of Example 4, the output of the LED-UV unit in the production of the adhesive sheet according to Example 2 was changed to 90%, and the widths of the cured portions at both ends in the sheet width direction are shown in Table 2. It was produced in the same manner as in Example 2 except that each was set to 1.25 mm.

[Example 5]
The pressure-sensitive adhesive sheet of Example 5 was produced in the same manner as in Example 2 except that the base material in the production of the pressure-sensitive adhesive sheet according to Example 2 ^{was changed to woodfree paper (basis weight: 60 g / m 2).}

[Example 6]
The pressure-sensitive adhesive sheet of Example 6 was produced in the same manner as in Example 2 except that the base material in the production of the pressure-sensitive adhesive sheet according to Example 2 was changed to a polyethylene terephthalate film (thickness: 50 μm).

[Comparative Example 1]
An adhesive sheet was produced in the same manner as in Example 1 except that the adhesive main agent was changed to the following.
An acrylic copolymer was obtained by copolymerizing 52 parts by mass of butyl acrylate (BA), 20 parts by mass of methyl methacrylate (MMA), and 28 parts by mass of 2-hydroxyethyl acrylate (2HEA). A solution of a resin (acrylic B) to which 2-isocyanate ethyl methacrylate (manufactured by Showa Denko KK, product name "Karenzu MOI" (registered trademark)) is added to this acrylic copolymer (adhesive main agent, solid). Minutes 35.0% by mass) were prepared. The addition rate was 90 mol% of 2-isocyanate ethyl methacrylate with respect to 100 mol% of 2HEA of the acrylic copolymer.
The weight average molecular weight (Mw) of the obtained resin (acrylic B) was 600,000, and Mw / Mn was 4.5. The weight average molecular weight Mw and the molecular weight distribution (Mw / Mn) of the resin (acrylic B) according to Comparative Example 1 were determined in the same manner as in Example 1.

[Comparative Example 2]
The pressure-sensitive adhesive sheet of Comparative Example 2 was produced in the same manner as in Example 2 except that UV was not irradiated in the production of the pressure-sensitive adhesive sheet according to Example 2.

[Evaluation of adhesive sheet]
The prepared adhesive sheet was evaluated as follows. The evaluation results are shown in Tables 1 and 2.

<Measurement method>
(Measurement method of tensile strength)
As a tensile tester for measuring the tensile strength, Autograph AG-IS manufactured by Shimadzu Corporation was used.
A first test piece having a width of 25 mm was prepared from the pressure-sensitive adhesive sheet. For the pressure-sensitive adhesive sheet having a cured portion and an uncured portion, a first test piece was prepared from a region corresponding to the uncured portion of the pressure-sensitive adhesive sheet.
A first semiconductor chip and a second semiconductor chip were attached to the first test piece to prepare a second test piece. As the first semiconductor chip and the second semiconductor chip, a semiconductor chip having a vertical dimension of 45 mm, a horizontal dimension of 35 mm, and a thickness dimension of 0.625 mm was used.
The sides of the first semiconductor chip and the second semiconductor chip having a vertical dimension of 45 mm were attached along the longitudinal direction of the first test piece.
The first semiconductor chip was attached to one end side in the longitudinal direction of the first test piece. The second semiconductor chip was attached to the other end side in the longitudinal direction of the first test piece. The distance between the first semiconductor chip and the second semiconductor chip attached to the first test piece was set to 35 μm.

The base material and the pressure-sensitive adhesive layer at both ends of the first test piece in the longitudinal direction were grasped with a gripper, and the tensile strength was measured with a tensile tester. The tensile strength _{F A1} when pulling 0.5mm of the first test piece (when pulling distance is 0.5mm) shown in Table 1.
The base material, the pressure-sensitive adhesive layer and the semiconductor chip at both ends of the second test piece in the longitudinal direction were grasped with a gripper, and the tensile strength was measured with a tensile tester. The tensile strength _{F B1} when pulling 0.5mm second specimen (when pulling distance is 0.5mm) shown in Table 1.
The unit of tensile strength is N.
Other conditions at the time of the tensile test are as follows.
Distance between grippers: 50 mm
Tensile speed: 50 mm / min

(Measurement method of Young's modulus)
A tensile test was conducted using a universal testing machine (“Autograph AG-IS500N” manufactured by Shimadzu Corporation) in accordance with JIS K7161 and JIS K7127. In the tensile test, the first test piece and the second test piece were fixed, and the tensile test was performed at a tensile speed of 50 mm / min. Then, a stress-strain curve at this time was created, and Young's modulus was calculated from the slope of the stress-strain curve at the initial stage of the test.
Table 1 shows the measurement results of Young's modulus of the adhesive sheet according to Example 1, Example 2 and Comparative Example 1.

As shown in Table 1, the pressure-sensitive adhesive sheets according to Examples 1 and 2 have _FB1 / _FA1 of 30 or less, the tensile strength of the portion of the pressure-sensitive adhesive sheet to which the semiconductor chip is not attached, and the semiconductor chip. There the ratio F _{B1 /} F _A1 and tensile strength of the portion is affixed is smaller than Comparative example 1. Therefore, according to the pressure-sensitive adhesive sheets according to Examples 1 and 2, when the pressure-sensitive adhesive sheet is expanded in the expanding step to extend the distance between the semiconductor chips, the difference in the amount of elongation of the pressure-sensitive adhesive sheet in the in-plane direction is obtained. Is small, the expandability is excellent, and the variation in the distance between semiconductor chips can be reduced.

(Evaluation method for suppressing the seepage of adhesive)
A roll was produced by winding an adhesive sheet having a width of 300 mm having hardened portions formed at both ends in the width direction. After 3 days after storing the roll at 40 ° C., it was confirmed visually or with a microscope whether or not the adhesive had exuded at the end of the roll. The evaluation criteria for exudation suppression were set as follows. In this embodiment, the evaluation A was judged to be acceptable.
・ Evaluation criteria for suppressing seepage Evaluation A: No change in appearance at the end of the roll Evaluation B: Change in appearance at the end of the roll

(Evaluation method of variation)
The pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were cut into a size of 210 mm × 210 mm to obtain a test pressure-sensitive adhesive sheet. 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 in the adhesive sheet.
The silicon wafer was diced, and a total of 49 chips were cut out so that the chips having a size of 3 mm × 3 mm had 7 rows in the X-axis direction and 7 rows in the Y-axis direction.
The release film of the test pressure-sensitive adhesive sheet was peeled off, and a total of 49 chips cut out as described above were attached to the center of the exposed pressure-sensitive adhesive layer. At this time, the chips were arranged in 7 rows in the X-axis direction and 7 rows in the Y-axis direction, and the distance between the chips was 35 μm in both the X-axis direction and the Y-axis direction.

Next, the test adhesive sheet to which the chip was attached was installed in a biaxially stretchable expanding device (separation device). FIG. 7 shows a plan view illustrating the expanding device 100. In FIG. 7, the X-axis and the Y-axis are orthogonal to each other, the positive direction of the X-axis is the + X-axis direction, the negative direction of the X-axis is the −X-axis direction, and the positive direction of the Y-axis. Is the + Y-axis direction, and the negative direction of the Y-axis is the −Y-axis direction. The test adhesive sheet 200 was installed in the expanding device 100 so that each side was parallel to the X-axis or the Y-axis. As a result, the MD direction of the base material in the test pressure-sensitive adhesive sheet 200 is parallel to the X-axis or the Y-axis. In FIG. 7, the chip is omitted.

As shown in FIG. 7, the expanding device 100 includes five holding means 101 (a total of 20 holding means 101) in each of the + X-axis direction, the −X-axis direction, the + Y-axis direction, and the −Y-axis direction. Of the five holding means 101 in each direction, the holding means 101A is located at both ends, the holding means 101C is located at the center, and the holding means 101B is located between the holding means 101A and the holding means 101C. Each side of the test adhesive sheet 200 was gripped by these holding means 101.

Here, as shown in FIG. 7, one side of the test adhesive sheet 200 is 210 mm. Further, the distance between the holding means 101 on each side is 40 mm. Further, the distance between the end portion (the apex of the sheet) on one side of the test adhesive sheet 200 and the holding means 101A existing on the side and closest to the end portion is 25 mm.

First Expanding Test Subsequently, a plurality of tension applying means (not shown) corresponding to each of the holding means 101 were driven to move the holding means 101 independently. The four sides of the test adhesive sheet were fixed with a gripping jig, and the test adhesive sheet was expanded at a speed of 5 mm / s in the X-axis direction and the Y-axis direction with an expansion amount of 200 mm. As a result of the first expanding test, the area of the adhesive sheet for testing was expanded to 381% compared to before expanding. In this example, this expansion test having an expansion amount of 200 mm may be referred to as a first expansion test. The adhesive sheets of Examples 5 and 6 could not be expanded.

After expanding the test pressure-sensitive adhesive sheet by the first expanding test, the expanded state of the test pressure-sensitive adhesive sheet 200 was maintained by a ring frame.
The variation was evaluated by calculating the standard deviation based on the positional relationship between the chips while maintaining the expanded state. The position of the chip on the test adhesive sheet was measured using a CNC image measuring machine (manufactured by Mitutoyo Co., Ltd., product name "Vision ACCEL"). The standard deviation was calculated using JMP13, a data analysis software manufactured by JMP. The evaluation criteria for variation were set as follows. In this example, evaluation A or evaluation B was judged to be acceptable.
-Evaluation criteria for variation Evaluation A: The standard deviation was 100 μm or less.
Evaluation B: The standard deviation was 200 μm or less.
Evaluation C: The standard deviation was 201 μm or more.

(Evaluation method of adhesive floating when elongation is 100%)
A third test piece cut out to a size of 150 mm in length and 25 mm in width along the elongated direction of the pressure-sensitive adhesive sheet was prepared so as to include the cured portion in which the energy ray-curable resin was cured. The third test piece was gripped by a pair of chucks of a tensile tester. As the tensile tester, Autograph AG-IS manufactured by Shimadzu Corporation was used. The distance between the chucks holding the third test piece was set to 100 mm. When the adhesive layer was stretched at a speed of 5 mm / sec until the distance between the chucks reached 200 mm, it was visually confirmed whether the cured portion of the pressure-sensitive adhesive layer was peeled off at the interface with the base material and floating was generated. The evaluation criteria for the adhesive floating when the elongation was 100% were set as follows. In this embodiment, the evaluation A was judged to be acceptable.
-Evaluation criteria for adhesive floating at 100% elongation Evaluation A: No floating of the hardened part of the adhesive layer occurred at 100% elongation Evaluation B: Lifting of the hardened part of the adhesive layer at 100% elongation Occurred in one or more places

(Evaluation method of area expandability)
At the time of the above-mentioned first expansion test, it was visually confirmed whether the cured portion of the pressure-sensitive adhesive layer was peeled off at the interface with the base material and the floating was generated. The evaluation criteria for area expandability were set as follows. In this embodiment, the evaluation A was judged to be acceptable. The adhesive sheets of Examples 5 and 6 could not be evaluated because they could not be expanded.
-Evaluation Criteria for Area Expandability Evaluation A: No floating of the cured portion of the pressure-sensitive adhesive layer occurred during the first expansion test.
Evaluation B: During the first expanding test, one or more floating portions of the cured portion of the pressure-sensitive adhesive layer occurred.

Since the adhesive sheets according to Examples 2 to 6 had hardened portions at both ends in the width direction, the seepage of the adhesive could be suppressed. Further, in the pressure-sensitive adhesive sheets according to Examples 2 and 3, the adhesive did not float when the elongation was 100% and during the first expanding test. It is probable that the cured portion of the pressure-sensitive adhesive sheet according to Examples 2 and 3 was formed by UV irradiation having an output of about 40% to 50%, and the degree of curing of the cured portion was appropriately controlled.

1 ... Adhesive sheet, 10 ... Base material, 20 ... Adhesive layer, CP1 ... First semiconductor chip, CP2 ... Second semiconductor chip.

Claims

Adhesive sheet
It has a base material and an adhesive layer,
The pressure-sensitive adhesive layer contains an energy ray-curable resin and contains
The pressure-sensitive adhesive layer has a cured portion in which the energy ray-curable resin is cured at both ends in the width direction of the pressure-sensitive adhesive layer, and an uncured portion in which the energy ray-curable resin is not cured.
A first test piece having a width of 25 mm is prepared from the pressure-sensitive adhesive sheet in the region corresponding to the uncured portion, and the base material and the pressure-sensitive adhesive layer at both ends of the first test piece in the longitudinal direction. and the tensile strength F A1 when pulling 0.5mm by gripping to a tensile tester uncured portions in the jaws,
The first semiconductor chip and the second semiconductor chip having a vertical dimension of 45 mm, a horizontal dimension of 35 mm, and a thickness dimension of 0.625 mm are the vertical dimensions of the first semiconductor chip and the second semiconductor chip. Is 45 mm along the longitudinal direction of the first test piece, and the distance between the first semiconductor chip and the second semiconductor chip is 35 μm, in the longitudinal direction of the first test piece. The first semiconductor chip is attached to the pressure-sensitive adhesive layer of the uncured portion on one end side, and the second semiconductor chip is attached to the pressure-sensitive adhesive layer of the uncured portion on the other end side in the longitudinal direction of the first test piece. A semiconductor chip is attached to prepare a second test piece, and the base material, the pressure-sensitive adhesive layer of the uncured portion, and the semiconductor chip at both ends in the longitudinal direction of the second test piece are gripped. in the tensile strength F B1 when gripped by the tensile 0.5mm by a tensile tester, but satisfies the following equation (equation 1A),
Adhesive sheet.
F B1 / F A1 ≤ 30 ... (Equation 1A)
A third test piece cut out to a size of 150 mm in length and 25 mm in width along the elongated direction of the pressure-sensitive adhesive sheet was prepared so as to include a cured portion in which the energy ray-curable resin was cured, and the third test piece was prepared. When the test piece of No. 1 was gripped by a pair of chucks with a distance between chucks of 100 mm and extended at a speed of 5 mm / sec until the distance between chucks reached 200 mm, floating occurred at the interface between the cured portion and the base material. do not,
The adhesive sheet according to claim 1.
In the adhesive sheet according to claim 1 or 2.
The adhesive sheet is placed in the first direction, the second direction opposite to the first direction, the third direction perpendicular to the first direction, and the direction opposite to the third direction. When the area ratio (S2 / S1) × 100 of the area S1 of the pressure-sensitive adhesive sheet before stretching and the area S2 of the pressure-sensitive adhesive sheet after stretching is 381%, the pressure-sensitive adhesive layer is stretched in four directions. The cured portion of the above does not peel off at the interface with the base material.
Adhesive sheet.
In the adhesive sheet according to any one of claims 1 to 3,
The tensile strength F A1 and the tensile strength F B1 satisfy the relationship of the following mathematical formula (Equation 1B).
Adhesive sheet.
1 ≤ F B1 / F A1 ≤ 30 ... (Equation 1B)
In the adhesive sheet according to any one of claims 1 to 4.
The Young's modulus Y A1 of the first test piece and the Young 's modulus Y B1 of the second test piece satisfy the relationship of the following mathematical formula (Equation 2A).
Adhesive sheet.
Y B1 / Y A1 ≤ 19 ... (Equation 2A)
In the adhesive sheet according to any one of claims 1 to 5.
The pressure-sensitive adhesive layer contains an acrylic pressure-sensitive adhesive.
Adhesive sheet.
In the adhesive sheet according to any one of claims 1 to 6,
The base material contains a urethane-based elastomer.
Adhesive sheet.
Used in the expanding process for expanding the distance between multiple semiconductor chips during the manufacturing process of semiconductor devices.
The adhesive sheet according to any one of claims 1 to 7.
In the adhesive sheet according to any one of claims 1 to 8.
The adhesive sheet has a long shape and is wound in a roll shape.
Adhesive sheet.
It is a method of manufacturing an adhesive sheet.
A step of applying a pressure-sensitive adhesive composition containing an energy ray-curable resin onto a base material to form a pressure-sensitive adhesive layer,
A step of irradiating both ends of the pressure-sensitive adhesive layer in the width direction with energy rays to cure the energy ray-curable resin to form a cured portion.
The entire cured portion is left outside the both ends in the width direction of the uncured portion in which the energy ray-curable resin is not cured, or a part of the cured portion is left outside the cured portion. Has a cutting process,
Adhesive sheet manufacturing method.
In the method for manufacturing an adhesive sheet according to claim 10,
The width of the cured portion left outside the both ends in the width direction of the uncured portion is 0.5 mm or more independently.
Adhesive sheet manufacturing method.
In the method for manufacturing an adhesive sheet according to claim 10 or 11.
After the step of cutting the outside of the cured portion, there is further a step of winding the cut adhesive sheet into a roll shape.
Adhesive sheet manufacturing method.