TW201842596A - Semiconductor device production method and adhesive sheet - Google Patents

Abstract

Provided are: a semiconductor device production method that includes steps (1)-(4) indicated below and that is a method for producing a semiconductor device using an adhesive sheet comprising an adhesive layer and a non-adhesive substrate containing expandable particles; and an adhesive sheet used in the production method. Step (1) is a step in which a frame member having an opening formed therein is attached to the adhesive surface of the adhesive layer. Step (2) is a step in which a semiconductor chip is placed on a part of the adhesive surface of the adhesive layer that is exposed in the opening of the frame member. Step (3) is a step in which the semiconductor chip, the frame member, and the adhesive surface of the adhesive layer on the periphery of the semiconductor chip are covered with a sealing material, the sealing material is cured, and a cured sealing body in which the semiconductor chip is sealed by the cured sealing material is obtained. Step (4) is a step in which the expandable particles are made to expand and the adhesive sheet is peeled from the cured sealing body. The present invention makes it possible to minimize the occurrence of positional displacement of a semiconductor chip in a production process for a fan-out package, has excellent productivity, and yields a semiconductor device having excellent flatness in a rewiring layer formation surface thereof.

Description

Manufacturing method of semiconductor device and adhesive sheet

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

In recent years, miniaturization, weight reduction, and high performance of electronic devices have progressed. With this, semiconductor devices mounted on electronic devices have also been required to be miniaturized, thinned, and high-density. Semiconductor wafers are sometimes mounted in packages close to their size. These packages are also called CSP (Chip Scale Package). Examples of CSPs are WLP (Wafer Level Package) completed from wafer size processing to the final step of packaging, and PLP (Panel Level Package) completed from processing to the final step of packaging with a panel size larger than the wafer size , Panel-level package) and so on.

WLP and PLP are classified into Fan-In type and Fan-out type. In the fan-out type WLP (hereinafter also referred to as "FOWLP") and PLP (hereinafter also referred to as "FOPLP"), the semiconductor wafer is covered with a sealing material to form a sealed body of the semiconductor wafer so that the area is larger than the wafer size. The redistribution layer and external electrodes are formed not only on the circuit surface of the semiconductor wafer, but also on the surface area of the sealing material.

However, FOWLP and FOPLP are manufactured through the following steps, for example, placing a plurality of semiconductor wafers on a temporary fixing adhesive sheet (hereinafter also referred to as a "temporary fixing sheet") to provide a fluidity seal A coating step of coating a material, a hardening step of thermally hardening the sealing material, a peeling step of peeling the temporarily fixing sheet from the sealing body, and a redistribution layer forming step of forming a redistribution layer on the exposed surface of the semiconductor wafer side. For the temporary fixing sheet used in the above steps, it is required that the position of the semiconductor wafer does not shift between the coating step and the hardening step (hereinafter also referred to as "sealing step"), and the sealing material does not enter The degree of adhesiveness between the bonding interface of the semiconductor wafer and the temporary fixing sheet is required, and after the sealing step, peelability that can be easily removed without residue is required. That is, the temporary fixing sheet used in the production of FOWLP and FOPLP is required to have both the adhesiveness at the time of use and the release property after use.

For example, Patent Document 1 discloses that in the manufacturing method of FOWLP, a substrate having a polyimide film and an adhesive layer made of a silicon-based adhesive on the surface of the substrate is used for temporary fixing. After the sealing step is performed on the sheet, the sheet for temporary fixing is peeled while being bent by hand. However, the step of peeling the sheet for temporary fixing by hand or the like is complicated, and from the viewpoint of improving productivity, it is required to peel the sheet for temporary fixing with a smaller external force.

As a sheet for temporary fixation having excellent peelability, for example, Patent Document 2 discloses a heat-peeling type adhesive for temporary fixation at the time of cutting an electronic component provided with a thermally expandable adhesive layer containing thermally expandable microspheres on at least one side of a substrate. Flakes. In the production of FOWLP and FOPLP, it is also considered to use the heat-peelable adhesive sheet described in Patent Document 2. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2015-32646 [Patent Document 2] Japanese Patent No. 3985853

[Questions to be Solved by the Invention]

However, based on a review by the inventors, it is understood that when the heat-peelable adhesive sheet described in Patent Document 2 is used as a temporary fixing sheet in the production of FOWLP and FOPLP, the elastic modulus of the thermally expandable adhesive layer is low, and In the aforementioned mounting step and sealing step, the mounted semiconductor wafer is sunk on the side of the adhesive sheet, and the position of the semiconductor wafer is shifted. As a result, after the sealing step, the surface on the semiconductor wafer side (hereinafter also referred to as the "rewiring layer forming surface") after the adhesive sheet is removed, a step occurs between the surface of the semiconductor wafer and the surface of the sealing material, so the flatness is poor , And the result that the position accuracy of the semiconductor wafer is reduced. Since the reduction in the flatness of the rewiring layer formation surface and the reduction in the positional accuracy of the semiconductor wafer are related to the reduction in the rewiring accuracy, it is desired to be suppressed. In addition, when the adhesive sheet is removed, even if the thermally expandable adhesive layer expands by heating, the semiconductor wafer sinks into the adhesive sheet side, and it is considered that it is difficult to peel off without a certain amount of external force.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a method for suppressing the occurrence of a positional shift of a semiconductor wafer in a manufacturing step of a fan-out package, which is excellent in productivity and excellent in flatness of a rewiring layer forming surface of the obtained semiconductor device A semiconductor device manufacturing method and an adhesive sheet used in the manufacturing method. [Means to solve the problem]

The inventors have found that in the manufacturing steps of a fan-out package, the above-mentioned problems can be solved by using an adhesive sheet having a specific layer including a swellable particle and a non-adhesive base material. That is, the present invention provides the following [1] to [11]. [1] A method for manufacturing a semiconductor device, which is a method for manufacturing a semiconductor device using an adhesive sheet having an adhesive layer and a non-adhesive base material containing expandable particles, and having the following steps ( 1) to (4), step (1): a step of attaching a frame member having an opening portion to an adhesive surface of an adhesive layer; step (2): placing a semiconductor wafer in the opening of the frame member A step of partially exposing a part of the adhesive surface of the adhesive layer; step (3): covering a peripheral portion of the semiconductor wafer among the adhesive surface of the semiconductor wafer, the frame member, and the adhesive layer with a sealing material, A step of hardening the sealing material to obtain a hardened sealed body in which the semiconductor wafer is sealed by the hardened sealing material; step (4): a step of expanding the expandable particles and peeling the adhesive sheet from the hardened sealing body . [2] The method for manufacturing a semiconductor device according to the above [1], further comprising the following step (5), step (5): a step of forming a redistribution layer on the adhesive sheet as a peeled hardened sealing body. [3] The method for manufacturing a semiconductor device according to the above [1] or [2], wherein the expandable particles are thermally expandable particles, and the step (4) is performed by heating the adhesive sheet to make the thermal expansion properties The step of expanding the particles to peel the adhesive sheet from the hardened sealing body. [4] The method for manufacturing a semiconductor device according to the above [3], wherein the expansion start temperature (t) of the thermally expandable particles is 120 to 250 ° C. [5] The method for manufacturing a semiconductor device according to the above [4], wherein the substrate satisfies the following requirements (1) to (2), and requirement (1): a storage modulus of the substrate at 100 ° C E '(100) is 2.0 × 10 ⁵ Pa or more; Element (2): The storage modulus E ′ (t) of the substrate at the expansion start temperature (t) of the thermally expandable particles is 1.0 × 10 ⁷ Pa the following. [6] The adhesive sheet according to any one of the above [1] to [5], wherein the average particle diameter of the expandable particles before expansion at 23 ° C. is 3 to 100 μm. [7] The method for manufacturing a semiconductor device according to any one of the above [1] to [6], wherein the shear storage modulus G ′ (23) of the adhesive material layer at 23 ° C. is 1.0 × 10 ⁴ to 1.0 × 10 ⁸ Pa. [8] The method for manufacturing a semiconductor device according to any one of the above [1] to [7], wherein the ratio of the thickness of the substrate at 23 ° C. to the thickness of the adhesive layer (substrate / The adhesive layer) is 0.2 or more. [9] The method for manufacturing a semiconductor device according to any one of the above [1] to [8], wherein the thickness of the substrate at 23 ° C. is 10 to 1000 μm, and the thickness of the adhesive layer is 1 ~ 60 μm. [10] The method for manufacturing a semiconductor device according to any one of the above [1] to [9], wherein a probe viscosity value on a surface of the substrate is less than 50 mN / 5 mmφ. [11] An adhesive sheet, which is an adhesive sheet used in the method for manufacturing a semiconductor device according to any one of the above [1] to [10], and has an adhesive layer, and an expandable particle and Non-adhesive substrate. [Inventive effect]

According to the present invention, it is possible to provide a method for manufacturing a semiconductor device capable of suppressing the occurrence of a positional shift of a semiconductor wafer in a manufacturing step of a fan-out package, and having excellent productivity, and an excellent flatness of the rewiring layer formation surface of the obtained semiconductor device, and the method Adhesive sheet used in the manufacturing method.

In the present invention, the "active ingredient" means a component other than a diluent solvent among the components contained in the target composition. In addition, the mass average molecular weight (Mw) is a value converted into a standard polystyrene measured by a gel permeation chromatography (GPC) method, and specifically is a value measured based on a method described in Examples.

In the present invention, for example, "(meth) acrylic acid" means both "acrylic acid" and "methacrylic acid", and other similar terms are also the same. In addition, regarding the preferred numerical range (such as the range of the content), the lower limit value and the upper limit value of the staged records can be combined independently. For example, based on the description of "preferably 10 to 90, more preferably 30 to 60", it is also possible to combine "better lower limit (10)" and "better upper limit (60)" to become "10 to 60" .

[Manufacturing method of semiconductor device] The manufacturing method of the semiconductor device of this embodiment is a method of manufacturing a semiconductor device using an adhesive sheet having an adhesive layer and a non-adhesive base material containing expandable particles, The method includes the following steps (1) to (4), (1): a step of bonding a frame member formed with an opening portion to an adhesive surface of an adhesive layer; (2): placing a semiconductor wafer on the aforementioned A step of a part of the adhesive surface of the adhesive layer exposed at the opening of the frame member; step (3): covering the semiconductor wafer, the frame member, and the semiconductor in the adhesive surface with the adhesive layer with a sealing material A step of hardening the sealing material at the peripheral portion of the wafer to obtain a hardened sealing body in which the semiconductor wafer is sealed by the hardened sealing material; step (4): expanding the expandable particles and sealing the adhesive sheet from the hardening; Step of body peeling. Hereinafter, first, the adhesive sheet used in the method for manufacturing a semiconductor device according to this embodiment will be described, and then each manufacturing step including steps (1) to (4) will be described.

<Adhesive sheet> 之 The adhesive sheet of this embodiment is not particularly limited as long as it has an adhesive layer and a non-adhesive base material (hereinafter also referred to as "expandable base material") containing expandable particles. The shape of the adhesive sheet can take all shapes such as sheet, tape, and label.

(Composition of Adhesive Sheet) Fig. 1 (A) is a cross-sectional view of an adhesive sheet 10 according to this embodiment. (1) As shown in FIG. 1 (A), the adhesive sheet 10 of this embodiment has an adhesive layer 12 on a substrate 11. In addition, the adhesive sheet of this embodiment may also have the constitution of the release material 13 on the adhesive surface 12a of the adhesive layer 12 as shown in the adhesive sheet 10a shown in FIG. 1 (B). When using the adhesive sheet 10a for the manufacturing method of the semiconductor device of this embodiment, the peeling material 13 is peeled and removed suitably.

Hereinafter, the expandable base material, the adhesive layer, and the release material used as needed in the adhesive sheet of this embodiment will be described in order.

(Expandable base material) (i) The expandable base material includes expandable particles and is a non-adhesive base material. Generally, the heat-expandable pressure-sensitive adhesive layer as described in Patent Document 2 has a thickness of a certain degree because the pressure-sensitive adhesive layer mainly contains a pressure-sensitive adhesive having a low modulus of elasticity as it contains sufficient expandable particles. Therefore, a positional deviation of the semiconductor wafer may occur between the mounting step and the sealing step of the semiconductor wafer, the semiconductor wafer sinks into the side of the adhesive sheet, and the formation surface of the rewiring layer cannot be flat. On the other hand, since the expandable particles of this embodiment form are contained in a non-adhesive resin having a high elastic modulus, the thickness adjustment, adhesive force, and viscoelastic modulus of the adhesive layer on which the semiconductor wafer is placed can be improved. Design freedom of control of waiting and so on. This can suppress the occurrence of positional deviation of the semiconductor wafer, and at the same time suppress the semiconductor wafer from sinking into the double-sided adhesive sheet, and can form a rewiring layer forming surface having excellent flatness. Furthermore, when using the adhesive sheet of this embodiment, since the semiconductor wafer is placed on the adhesive surface of the adhesive layer, the expandable substrate and the redistribution layer forming surface are not in direct contact. Thereby, it is suppressed that a part of the residue derived from the expandable particles and the greatly deformed adhesive layer adhere to the redistribution layer forming surface, and the uneven shape formed on the thermally expandable adhesive layer is prevented from being transferred to the redistribution layer forming surface. The smoothness is reduced, and a redistribution layer forming surface having excellent cleanness and smoothness can be obtained.

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

The expandable substrate of the adhesive sheet is a non-adhesive substrate. In the present invention, the determination of whether the substrate is non-adhesive refers to the surface of the target substrate. If the probe viscosity value measured according to JIS Z0237: 1991 is less than 50mN / 5mmφ, the substrate is judged to be "non-adhesive" Adhesive substrate ". Herein, the probe viscosity of the surface of the expansive substrate used in this embodiment is generally less than 50mN / 5mmφ, but preferably less than 30mN / 5mmφ, more preferably less than 10mN / 5mmφ, and even better. It is less than 5mN / 5mmφ. In addition, in this specification, the specific measurement method of the probe viscosity value on the surface of an expandable substrate is the method described in an Example.

The expandable base material included in the adhesive sheet of the present embodiment includes a resin and expandable particles, but as long as the effect of the present invention is not impaired, an additive for the base material may be contained as necessary. In addition, the expandable substrate may be formed of a resin composition (y) containing a resin and expandable particles. Hereinafter, each component contained in the resin composition (y) which is a forming material of an expandable base material is demonstrated.

<Resin> The resin contained in the resin composition (y) is not particularly limited as long as it is a resin capable of making the expandable substrate non-adhesive, and may be a non-adhesive resin or an adhesive resin. That is, even if the resin contained in the resin composition (y) is an adhesive resin, as long as the expandable substrate is formed from the resin composition (y), the adhesive resin and the polymerizable compound undergo a polymerization reaction so that The obtained resin may be a non-adhesive resin, and the expandable substrate containing the resin may be made non-adhesive.

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

The content of the resin is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and still more preferably 65 to 90% by mass based on the total amount (100% by mass) of the active ingredient of the resin composition (y). And more preferably 70 to 85% by mass.

The resin contained in the resin composition (y) preferably contains one or more selected from the group consisting of an acrylic urethane resin and an olefin resin. As the acrylic urethane resin, the following resin (U1) is preferred. · Urethane prepolymer (UP) is an acrylic urethane resin (U1) formed by polymerizing a vinyl compound containing a (meth) acrylate.

[Acrylic urethane-based resin (U1)] The urethane prepolymer (UP) as the main chain of the acrylic urethane-based resin (U1) is exemplified by the reaction of a polyol and a polyisocyanate Thing. In addition, a urethane prepolymer (UP) is preferably used, and a chain extension reaction can be performed by using a chain extender.

Examples of the polyol used as a raw material of the urethane prepolymer (UP) include, for example, an alkylene polyol, an ether polyol, an ester polyol, an esteramine polyol, and an ester / ether polyol. Alcohols, carbonate-type polyols, and the like. These polyols can be used alone or in combination of two or more.多元 As the polyhydric alcohol used in this embodiment, a diol is preferable, an ester diol, an alkylene diol, and a carbonate diol are more preferable, and an ester diol and a carbonate diol are more preferable.

Examples of the ester-type diol include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol; ethylene glycol Alcohols such as alcohols, propylene glycol, diethylene glycol, dipropylene glycol, etc .; 1 or 2 or more diols selected with phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid , 4,4-diphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, chloro bridge acid (Het acid), horse Maleic acid, fumaric acid, itaconic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, hexahydrophthalic acid, hexahydroisophthalic acid, six Polycondensates of one or more types of dicarboxylic acids such as hydroterephthalic acid, methylhexahydrophthalic acid and the like, and anhydrides thereof. Specific examples include poly (ethylene adipate), poly (butylene adipate), poly (hexamethylene adipate), poly (hexamethylene isophthalate), and poly (hexamethylene isophthalate). Neopentyl didiol, poly (butylene adipate), poly (butylene adipate), poly (butylene adipate), poly (butylene adipate), poly (butylene adipate) Diethylene glycol adipate, poly (polytetramethylene ether) adipate glycol, poly (3-methylpentyl adipate) glycol, polyethylene adipate Ester glycol, polybutylene sebacate diol, polybutylene sebacate diol, polybutylene sebacate diol, and neopentyl terephthalate glycol.

Examples of the alkylene glycol include alkylene glycols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol; Alkane glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol; polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutanediol; polyoxyethylene such as polytetramethylene glycol Alkanediols, etc.

Examples of the carbonate-type diol include 1,4-tetramethylene carbonate, carbonate, 1,5-pentamethylene carbonate, 1,6-hexamethylene carbonate, and 1 carbonate. 2,2-propanediol, 1,3-propane carbonate, 2,2-dimethylpropane carbonate, 1,7-heptamethylene carbonate, 1,8-octamethylene carbonate, 1,4-cyclohexyl carbonate, and the like.

Examples of the polyisocyanate used as a raw material for the urethane prepolymer (UP) include aromatic polyisocyanate, aliphatic polyisocyanate, and alicyclic polyisocyanate. These polyisocyanates can be used alone or in combination of two or more. Moreover, these polyisocyanates can also be trimethylolpropane addition-shaped modifiers, biuret-type modifiers that react with water, and isocyanurate-type modifiers containing isocyanurate rings.

Among these, as the polyisocyanate used in this embodiment, diisocyanate is preferred, and more preferably selected from 4,4'-diphenylmethane diisocyanate (MDI) and 2,4-toluene diisocyanate (2,4 -TDI), 2,6-toluene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI) and alicyclic diisocyanate.

Examples of the alicyclic diisocyanate include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 1,3-cyclopentane diisocyanate, 1 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, and the like are preferred. Furone diisocyanate (IPDI).

In this embodiment, as a reactant between a urethane prepolymer (UP) diol and a diisocyanate, which is the main chain of the acrylic urethane resin (U1), it is preferable to have Ethylene unsaturated linear urethane prepolymer. As a method for introducing an ethylenically unsaturated group at both ends of the linear urethane prepolymer, the end of the linear urethane prepolymer obtained by reacting a diol with a diisocyanate compound is exemplified. Method for reacting NCO group with hydroxyalkyl (meth) acrylate.

Examples of the hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylic acid. 2-hydroxybutyl ester, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like.

The vinyl compound as a side chain of the acrylic urethane-based resin (U1) contains at least a (meth) acrylate. The (meth) acrylate is preferably one or more selected from alkyl (meth) acrylate and hydroxyalkyl (meth) acrylate, and more preferably a combination of (meth) acrylate and (meth) acrylic acid Hydroxyalkyl esters.

When an alkyl (meth) acrylate and a hydroxyalkyl (meth) acrylate are used in combination, the blending ratio of the hydroxyalkyl (meth) acrylate is preferably 0.1 to 100 parts by mass of the (meth) acrylate. 100 parts by mass, more preferably 0.5 to 30 parts by mass, still more preferably 1.0 to 20 parts by mass, even more preferably 1.5 to 10 parts by mass.

The alkyl carbon number of the alkyl (meth) acrylate is preferably from 1 to 24, more preferably from 1 to 12, still more preferably from 1 to 8, and even more preferably from 1 to 3.

The hydroxyalkyl (meth) acrylate is the same as the hydroxyalkyl (meth) acrylate used to introduce an ethylenically unsaturated group at both ends of the linear urethane prepolymer. .

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

The content of the (meth) acrylate in the vinyl compound is preferably 40 to 100% by mass, more preferably 65 to 100% by mass, and more preferably relative to the total amount (100% by mass) of the vinyl compound. It is 80 to 100% by mass, and more preferably 90 to 100% by mass.

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

The acrylic urethane resin (U1) used in this embodiment is obtained by mixing a urethane prepolymer (UP) with a vinyl compound containing a (meth) acrylate, and polymerizing the two. In this polymerization, it is preferred to perform the polymerization by adding a radical initiator.

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

[Olefin Resin] (i) As the resin contained in the resin composition (y), it is preferred that the olefin resin is a polymer having at least a constituent unit derived from an olefin monomer. As the olefin monomer, an α-olefin having 2 to 8 carbon atoms is preferred, and specific examples thereof include ethylene, propylene, butene, isobutylene, and 1-hexene. Of these, ethylene and propylene are preferred.

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

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

For example, as the acid-modified olefin-based resin which is subjected to acid modification to the olefin-based resin, the modified polymer obtained by graft-polymerizing an unsaturated carboxylic acid or an anhydride thereof to the above-mentioned non-modified olefin-based resin is exemplified. Examples of the unsaturated carboxylic acid or its anhydride include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaric acid, tetrahydrophthalic acid, aconitic acid, (meth) acrylic acid, and horse Maleic anhydride, itaconic anhydride, glutaric anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic anhydride, tetrahydrophthalic anhydride, and the like. The unsaturated carboxylic acid or its anhydride may be used alone or in combination of two or more.

Examples of acrylic modified olefin resins which are modified by acrylic acid to olefin resins include modified polymers of the main chain of the above-mentioned non-modified olefin resin graft polymerized as (meth) acrylic acid alkyl esters as side chains. . The number of carbon atoms of the alkyl group in the fluorene as the alkyl (meth) acrylate is preferably from 1 to 20, more preferably from 1 to 16, and even more preferably from 1 to 12. As the above-mentioned alkyl (meth) acrylate, for example, the same compounds as those which can be selected as the monomer (a1 ') described later are exemplified.

Examples of the hydroxy-modified olefin-based resin in which the olefin-based resin is modified with a hydroxyl group include modified polymers in which a main chain of the above-mentioned non-modified olefin-based resin is graft-polymerized with a hydroxyl-containing compound. Examples of the hydroxyl-containing compound include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxy (meth) acrylate Butyl ester, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like; hydroxyalkyl (meth) acrylates; unsaturated alcohols such as vinyl alcohol and allyl alcohol.

[Resins other than acrylic urethane resin and olefin resin] In the present embodiment, the resin composition (y) may contain an acrylic urethane resin as long as the effect of the present invention is not impaired. Resins other than resins and olefin resins. Examples of such resins are vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, etc .; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate Polyester resins such as polystyrene; acrylonitrile-butadiene-styrene copolymer; cellulose triacetate; polycarbonate; polyurethanes not equivalent to acrylic urethane resins Polyfluorene; Polyetheretherketone; Polyetherfluorene; Polyphenylenesulfide; Polyetherimide resins such as polyetherimide, polyimide, etc .; Polyimide resins; acrylic resins; fluorine resins, etc. . The content ratio of the resin other than the acrylic urethane resin and the olefin resin is preferably less than 30 parts by mass, and more preferably less than 100 parts by mass based on 100 parts by mass of the total amount of the resin contained in the resin composition (y). 20 parts by mass, more preferably less than 10 parts by mass, even more preferably less than 5 parts by mass, and still more preferably less than 1 part by mass.

<Expansive particles> Expansive particles are not particularly limited as long as they can expand and form undulations on the adhesive layer by external stimuli, and can reduce adhesion to the adhesive body. Examples of the expandable particles include, for example, heat-expandable particles that expand by heating, and energy-line expandable particles that expand by irradiation with energy rays. From the viewpoint of wide usability and handling, heat-expandable particles are preferred. .

The thermally expandable particles are preferably particles adjusted to have an expansion start temperature (t) of 120 to 250 ° C. In addition, in this specification, the expansion start temperature (t) of a thermally expandable particle means the value measured based on the following method. [Method for measuring the expansion start temperature (t) of thermally expandable particles] Prepared in an aluminum pan with a diameter of 6.0 mm (inner diameter 5.65 mm) and a depth of 4.8 mm, add 0.5 mg of the thermally expandable particles to be measured, and cover it Hold the aluminum cover (5.6mm diameter, 0.1mm thickness) sample. Using a dynamic viscoelasticity measuring device, a height of the sample was measured by applying a force of 0.01 N to the sample from the upper part of the aluminum cover by a pressurizer. Next, in a state where a force of 0.01 N is applied by the pressurizer, it is heated from 20 ° C. to 300 ° C. at a heating rate of 10 ° C./min, and the displacement amount of the pressurizer in the vertical direction is measured to start the displacement in the positive direction. The temperature was taken as the expansion start temperature (t).

The heat-expandable particles are preferably a microencapsulated foaming agent composed of an outer casing made of a thermoplastic resin and an inner packaging component enclosed by the outer casing and vaporized when heated to a specific temperature. Examples of the thermoplastic resin constituting the shell of the microencapsulated foaming agent are, for example, vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride , Juyi and so on.

Examples of the internal components enclosed in the shell include propane, butane, pentane, hexane, heptane, octane, nonane, decane, isobutane, isopentane, isohexane, isoheptane, Isooctane, isononane, isodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, neopentane, dodecane, isododecane, cyclodeca Trioxane, hexylcyclohexane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, isotridecane, 4-methyldodecane, iso Tetradecane, isopentadecane, isohexadecane, 2,2,4,4,6,8,8-heptamethylnonane, isoheptadecane, isooctadecane, isodecadecane, 2 , 6,10,14-tetramethylheptadecane, cyclotridecane, heptylcyclohexane, n-octylcyclohexane, cyclopentadecane, nonylcyclohexane, decylcyclohexane, ten Pentaalkylcyclohexane, cetylcyclohexane, heptadecylcyclohexane, octadecylcyclohexane and the like. These ingredients can be used alone or in combination of two or more.膨胀 The expansion start temperature (t) of the thermally expandable particles can be adjusted by appropriately selecting the type of the inclusion component.

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

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

The 90% particle diameter (D ₉₀ ) of the expandable particles used in this embodiment before expansion at 23 ° C. is preferably 10 to 150 μm, more preferably 20 to 100 μm, still more preferably 25 to 90 μm, and even more preferably It is 30 to 80 μm. The 90% particle size (D ₉₀ ) before the expansion of thermally expandable particles means the swelling property before expansion measured using a laser diffraction particle size distribution measuring device (for example, manufactured by Malvern, product name "Mastersizer 3000"). In the particle distribution of the particles, the cumulative volume frequency calculated from the smaller particle diameter of the expandable particles before expansion corresponds to a particle diameter of 90%.

The content of the expandable particles is preferably 1 to 40% by mass, more preferably 5 to 35% by mass, and still more preferably 10 to 30% by mass relative to the total amount (100% by mass) of the effective component of the resin composition (y). %, More preferably 15 to 25% by mass.

<Additives for Substrates> The resin composition (y) used in the present embodiment may contain additives for substrates contained in a substrate included in a general adhesive sheet, as long as the effect of the present invention is not impaired. Examples of such additives for substrates include ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, slip agents, anti-blocking agents, colorants, and the like. In addition, each of these base material additives may be used alone, or two or more kinds may be used in combination. When such additives for substrates are contained, the content of the additives for each substrate is preferably 0.0001 to 20 parts by mass, and more preferably 0.001 to 10 parts by mass relative to 100 parts by mass of the aforementioned resin in the resin composition (y). .

<Solventless resin composition (y1)> 之一 One aspect of the resin composition (y) used in this embodiment, for example, an oligomer having an ethylenically unsaturated group with a mass average molecular weight (Mw) of 50,000 or less is exemplified. The solvent-free resin composition (y1) without a solvent and an energy ray polymerizable monomer and the above-mentioned swellable particles.溶剂 The solventless resin composition (y1) is not a solvent, but the energy ray polymerizable monomer contributes to improving the plasticity of the oligomer.照射 The coating film formed from the solventless resin composition (y1) is irradiated with energy rays to obtain an expandable substrate.

The type, shape, and amount (content) of the swellable particles prepared in the solventless resin composition (y1) are as described above.

The mass average molecular weight (Mw) of the aforementioned oligomer contained in the solventless resin composition (y1) is 50,000 or less, but preferably 1,000 to 50,000, more preferably 2,000 to 40,000, and even more preferably 3,000 to 35,000. It is more preferably 4,000 to 30,000.

In addition, as the oligomer, any resin having an ethylenically unsaturated group with a mass average molecular weight (Mw) of 50,000 or less in the resin contained in the resin composition (y) may be used, but the above-mentioned amine group is preferred. Formate prepolymer (UP). In addition, as the oligomer, a modified olefin-based resin having an ethylenically unsaturated group can also be used.

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

Examples of the energy ray polymerizable monomer include isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentyl (meth) acrylate, and dicyclopentenyl (meth) acrylate. Alicyclic polymerizable compounds such as methyl ester, cyclohexyl (meth) acrylate, adamantane (meth) acrylate, tricyclodecyl acrylate, etc .; phenylhydroxypropyl acrylate, benzyl acrylate, ethoxylate Aromatic polymerizable compounds such as alkane-modified acrylate; heterocyclic polymerization of tetrahydrofurfuryl (meth) acrylate, morpholine acrylate, N-vinylpyrrolidone, N-vinylcaprolactam, etc. Sexual compounds. These energy ray polymerizable monomers can be used alone or in combination of two or more.

The content ratio of the oligomer to the energy ray polymerizable monomer (the oligomer / energy ray polymerizable monomer) in the solventless resin composition (y1) is preferably 20/80 in terms of mass ratio ~ 90/10, more preferably 30/70 to 85/15, and still more preferably 35/65 to 80/20.

In this embodiment, the solventless resin composition (y1) is preferably further formulated with a photopolymerization initiator.含有 By containing a photopolymerization initiator, the hardening reaction can proceed sufficiently even if it is irradiated with a relatively low energy energy ray.

Examples of the photopolymerization initiator include 1-hydroxy-cyclohexyl-phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin phenyl sulfide, tetramethyl Kithiuram monosulfide, azobisisobutyronitrile, biphenylhydrazone, biacetamidine, 8-chloroanthraquinone, etc. The photopolymerization initiators can be used alone or in combination of two or more.

The blending amount of the photopolymerization initiator is preferably from 0.01 to 5 parts by mass, more preferably from 0.01 to 4 parts by mass, and more than the total amount (100 parts by mass) of the aforementioned oligomer and energy ray polymerizable monomer. It is preferably 0.02 to 3 parts by mass.

<Storage modulus of base material> The storage modulus E '(23) at 23 ° C of the expansive base material of the adhesive sheet of this embodiment is preferably 1.0 × 10 ⁶ Pa or more, and more preferably 5.0 × 10 ⁶ ～ 5.0 × 10 ¹² Pa, more preferably 1.0 × 10 ⁷ ～ 1.0 × 10 ¹² Pa, even more preferably 5.0 × 10 ⁷ ～ 1.0 × 10 ¹¹ Pa, and still more preferably 1.0 × 10 ⁸ ～ 1.0 × 10 ¹⁰ Pa. By using an expansive substrate having a storage modulus E '(23) within the above range, the position of the semiconductor wafer can be prevented from shifting, and the semiconductor wafer can also be prevented from sinking into the adhesive layer. For example, the semiconductor wafer can be placed in such a manner that its circuit surface is covered with the adhesive surface of the adhesive layer. In the mounting of semiconductor wafers, conventional devices such as flip-chip bonding machines and wafer bonding machines are sometimes used. In the above sequence, when using a flip-chip bonding machine or a wafer bonding machine, when a semiconductor wafer is placed on the adhesive layer of the adhesive sheet, the semiconductor wafer is excessive due to the pressing force of pressing the semiconductor wafer in the thickness direction of the adhesive sheet. It may sink into the thickness direction side of the adhesive layer. In addition, when using a flip-chip bonding machine or a wafer bonding machine, when a semiconductor wafer is placed on the adhesive sheet, the semiconductor wafer is also moved horizontally to the adhesive sheet, so there is also a semiconductor wafer at the level of the adhesive layer. There is a possibility that the position of the direction may be shifted. However, these problems can also be solved by using an expandable substrate that satisfies the above-mentioned storage modulus E '(23). In this specification, the storage modulus E 'of the expandable substrate at a specific temperature means a value measured by the method described in the examples.

In addition, it is preferable that the storage substrate provided by the adhesive sheet of the present embodiment has a storage modulus that satisfies the following requirement (1).・ Requirement (1): The storage modulus E '(100) of the aforementioned expandable substrate at 100 ° C is 2.0 × 10 ⁵ Pa or more. By having an expandable substrate that satisfies the requirement (1), even in the temperature environment of the sealing step in the manufacturing process of FOWLP and FOPLP, the flow of the expandable particles can be suppressed to a good degree, so it is set on the expandable substrate. The adhesive surface of the upper adhesive layer is also difficult to deform. As a result, the position of the semiconductor wafer can be prevented from being shifted, and the semiconductor wafer can be prevented from sinking toward the adhesive layer.

Based on the above viewpoint, the storage modulus E '(100) of the expandable substrate is preferably 4.0 × 10 ⁵ Pa or more, more preferably 6.0 × 10 ⁵ Pa or more, and even more preferably 8.0 × 10 ⁵ Pa or more. It is more preferably 1.0 × 10 ⁶ Pa or more. In addition, in the sealing step, from the viewpoint of effectively suppressing the positional displacement of the semiconductor wafer, the storage modulus E '(100) of the expandable substrate is preferably 1.0 × 10 ¹² Pa or more, and more preferably 1.0 × 10 ¹¹ Pa or less is more preferably 1.0 × 10 ¹⁰ Pa or less, and still more preferably 1.0 × 10 ⁹ Pa or less.

In addition, when the expandable base material included in the adhesive sheet of the present embodiment contains thermally expandable particles as the expandable particles, the storage modulus preferably satisfies the following requirement (2). · Requirement (2): The storage modulus E '(t) of the expandable substrate at the expansion start temperature (t) of the thermally expandable particles is 1.0 × 10 ⁷ Pa or less. By having an expandable substrate that satisfies the requirement (2), at a temperature at which the thermally expandable particles are expanded, the expandable substrate is easily deformed following the volume expansion of the thermally expandable particles, and it is easy to form unevenness on the adhesive surface of the adhesive layer. Thereby, it can peel from an object with a little external force.

Based on the above viewpoint, the storage modulus E '(t) of the expandable substrate is preferably 9.0 × 10 ⁶ Pa or less, more preferably 8.0 × 10 ⁶ Pa or less, and still more preferably 6.0 × 10 ⁶ Pa or less. It is more preferably 4.0 × 10 ⁶ Pa or less. In addition, from the viewpoint of suppressing the flow of the thermally expansible particles, improving the shape retention of the unevenness formed on the adhesive surface of the adhesive layer, and improving the peelability, the storage modulus E '(t) of the expandable substrate, It is preferably 1.0 × 10 ³ Pa or more, more preferably 1.0 × 10 ⁴ Pa or more, and still more preferably 1.0 × 10 ⁵ Pa or more.

(Adhesive agent layer) 之 The adhesive agent layer included in the adhesive sheet according to this embodiment may include an adhesive resin, and may include an adhesive such as a cross-linking agent, an adhesion-imparting agent, a polymerizable compound, and a polymerization initiator, as required. Additives. In addition, from the viewpoint of preventing the semiconductor wafer placed on the adhesive layer from sinking due to the heating in the sealing step, the adhesive layer is preferably a non-swellable adhesive layer.

In the adhesive sheet of this embodiment, the adhesive force of the adhesive surface of the adhesive layer before expansion of the expandable particles at 23 ° C. is preferably 0.1 to 10.0 N / 25 mm, more preferably 0.2 to 8.0 N / 25 mm, and more It is preferably from 0.4 to 6.0 N / 25 mm, and even more preferably from 0.5 to 4.0 N / 25 mm.若 If the adhesive force is 0.1N / 25mm or more, the position of the semiconductor wafer in the sealing step can be prevented from being sufficiently fixed. On the other hand, if the adhesive force is 10.0 N / 25 mm or less, when it is peeled from the adherend, it can be easily peeled with a slight external force. In addition, the said adhesive force means the value measured by the method described in an Example.

In the adhesive sheet of this embodiment, the shear storage modulus G '(23) of the adhesive layer at 23 ° C is preferably 1.0 × 10 ⁴ to 1.0 × 10 ⁸ Pa, and more preferably 5.0 × 10 ⁴ ∼5.0 × 10 ⁷ Pa, and more preferably 1.0 × 10 ⁵ to 1.0 × 10 ⁷ Pa. In the case of an adhesive sheet having a plurality of adhesive layers, the shear storage modulus G '(23) of the adhesive layer to which the semiconductor wafer is bonded is preferably within the above range, and the semiconductor wafer from the expandable substrate is preferred. The total shear storage modulus G '(23) of the adhesive layer on the bonding side is within the above range. If the shear storage modulus G '(23) of the adhesive layer is 1.0 × 10 ⁴ Pa or more, the position of the semiconductor wafer can be prevented from shifting, and the semiconductor wafer can also be prevented from sinking into the adhesive layer. On the other hand, if the shear storage modulus G '(23) of the adhesive layer is 1.0 × 10 ⁸ Pa or less, it is easy to form unevenness on the surface of the adhesive layer by the expansion of the expandable particles in the expandable substrate. As a result, it can be easily peeled with a little force. In addition, in this specification, the shear storage modulus G '(23) of an adhesive layer means the value measured by the method as described in an Example.

The thickness of the adhesive layer of the adhesive sheet of this embodiment is based on the viewpoint of exhibiting excellent adhesion, and the viewpoint that the surface of the adhesive layer that is easily formed by the expansion of the expandable particles in the expandable substrate is uneven. It is preferably 1 to 60 μm, more preferably 2 to 50 μm, still more preferably 3 to 40 μm, and still more preferably 5 to 30 μm.

In the adhesive sheet of this embodiment, the ratio of the thickness of the expandable substrate at 23 ° C to the thickness of the adhesive layer (expandable substrate / adhesive layer) is based on flattening the rewiring layer formation surface and preventing the formation of semiconductor wafers. The viewpoint of positional displacement is preferably 0.2 or more, more preferably 0.5 or more, still more preferably 1.0 or more, still more preferably 5.0 or more, and the viewpoint of being an adhesive sheet that can be easily peeled off with a little force when peeling off. It is preferably 1,000 or less, more preferably 200 or less, still more preferably 60 or less, and even more preferably 30 or less.厚度 The thickness of the adhesive layer means a value measured based on the method described in the examples.

The adhesive layer may be formed of an adhesive composition containing an adhesive resin. Hereinafter, each component contained in the adhesive composition of the material for forming the adhesive layer will be described.

<Adhesive resin> As the adhesive resin used in this embodiment, it is preferred that the resin has adhesiveness alone and a polymer having a mass average molecular weight (Mw) of 10,000 or more. The mass average molecular weight (Mw) of the adhesive resin used in this embodiment is preferably 10,000 to 2 million, more preferably 20,000 to 1.5 million, and still more preferably 30,000 to 100 from the viewpoint of improving the adhesive force. Million.

Examples of the adhesive resin include rubber resins such as acrylic resins, urethane resins, polyisobutylene resins, polyester resins, olefin resins, silicone resins, and polyvinyl ether resins. These adhesive resins can be used alone or in combination of two or more. When the adhesive resin is a copolymer having two or more constituent units, the form of the copolymer is not particularly limited, and may be any of a block copolymer, a random copolymer, and a graft copolymer. By.

The adhesive resin used in this embodiment may also be an energy-ray-curable adhesive resin in which a polymerizable functional group is introduced into a side chain of the adhesive resin. Examples of the polymerizable functional group include (meth) acrylic acid fluorenyl and vinyl. In addition, examples of the energy rays include ultraviolet rays and electron beams, and ultraviolet rays are preferred.

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

In this embodiment, based on the viewpoint of exhibiting excellent adhesion and the expansion of the swellable particles in the swellable substrate by heat treatment, and the ease of forming unevenness on the surface of the formed adhesive layer, the adhesive resin is Good contains acrylic resin. The content of the acrylic resin in the adhesive resin is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, relative to the total amount of the adhesive resin (100% by mass) contained in the adhesive composition. It is more preferably 70 to 100% by mass, and even more preferably 85 to 100% by mass.

[Acrylic Resin] In this embodiment, as the acrylic resin that can be used as an adhesive resin, for example, polymerization of a constituent unit including an alkyl (meth) acrylate derived from an alkyl group having a linear or branched chain is exemplified. The substance includes a polymer derived from a constituent unit of a (meth) acrylate having a cyclic structure, and the like.

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

The acrylic resin is more preferably a structural unit (a1) derived from an alkyl (meth) acrylate (a1 ') (hereinafter also referred to as a "monomer (a1')") and a functional group-containing unit. (A2 ') (hereinafter also referred to as "monomer (a2')") as an acrylic copolymer (A1) as a constituent unit (a2).

The number of carbon atoms of the alkyl group in the monomer (a1 ') is preferably from 1 to 24, more preferably from 1 to 12, still more preferably from 2 to 10, and even more preferably 4 from the viewpoint of improving the adhesion characteristics. ~ 8. In addition, the alkyl group possessed by the monomer (a1 ') may be a linear alkyl group or a branched alkyl group.

Examples of the monomer (a1 ') include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid 2- Ethylhexyl ester, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, and the like. These monomers (a1 ') can be used alone or in combination of two or more kinds. As the monomer (a1 '), butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate are preferred.

The content of the constituent unit (a1) is preferably 50 to 99.9 mass%, more preferably 60 to 99.0 mass%, and even more preferably 70 to the total constituent unit (100% by mass) of the acrylic copolymer (A1). -97.0% by mass, more preferably 80-95.0% by mass.

Examples of the functional group possessed by the monomer (a2 ') include a hydroxyl group, a carboxyl group, an amine group, and an epoxy group. That is, as the monomer (a2 '), for example, a hydroxyl-containing monomer, a carboxyl-containing monomer, an amine-containing monomer, an epoxy-containing monomer, and the like are exemplified. These monomers (a2 ') can be used alone or in combination of two or more kinds. Among these, the monomer (a2 ') is preferably a hydroxyl-containing monomer and a carboxyl-containing monomer.

Examples of the hydroxyl-containing monomer include, for example, the same hydroxyl-containing compounds described above.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids such as (meth) acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid, and citraconic acid. Acids and their anhydrides; 2- (propenyloxy) ethyl salicylate, 2-carboxyethyl (meth) acrylate, and the like.

The content of the constituent unit (a2) is preferably 0.1 to 40 mass%, more preferably 0.5 to 35 mass%, and more preferably 1.0 relative to the total constituent unit (100 mass%) of the acrylic copolymer (A1). -30 mass%, more preferably 3.0-25 mass%.

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

Examples of the monomer (a3 ') include, for example, olefins such as ethylene, propylene, and isobutylene; halogenated olefins such as vinyl chloride and vinylidene chloride; and diene systems such as butadiene, isoprene, and chloroprene. Monomers; cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopentene (meth) acrylate (Meth) acrylates having a cyclic structure such as dicyclopentenyloxyethyl (meth) acrylate, fluorimide (meth) acrylate, and the like; styrene, α-methylstyrene, vinyl Toluene, vinyl formate, vinyl acetate, acrylonitrile, (meth) acrylamide, (meth) acrylonitrile, (meth) acrylfluorenylmorpholine, N-vinylpyrrolidone, and the like.

The acrylic copolymer (A1) may be an energy ray-curable acrylic copolymer in which a polymerizable functional group is introduced into a side chain. As the polymerizable functional group and the energy ray system, fluorene is as described above. In addition, the polymerizable functional group may be substituted by bonding the acrylic copolymer having the above-mentioned constituent units (a1) and (a2) with a functional group having a constituent unit (a2) which can be combined with the acrylic copolymer. The compound of the group and the polymerizable functional group is introduced and reacted. As the aforementioned compound, for example, (meth) acryloxyethyl isocyanate, (meth) acrylfluorenyl isocyanate, glycidyl (meth) acrylate, and the like are exemplified.

<Crosslinking agent> 时 In the present embodiment, when the adhesive composition contains a functional group-containing adhesive resin such as the acrylic copolymer (A1) described above, it is preferable to further contain a crosslinking agent. The crosslinking agent reacts with an adhesive resin having a functional group, and uses the functional group as a starting point for crosslinking to crosslink the adhesive resins with each other.

Examples of the crosslinking agent include, for example, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, and a metal chelating agent-based crosslinking agent. These crosslinking agents can be used alone or in combination of two or more. Among these crosslinking agents, an isocyanate-based crosslinking agent is preferred from the viewpoints of improving the cohesive force, improving the adhesive force, and the ease of obtaining.

The content of the crosslinking agent can be appropriately adjusted by the number of functional groups of the adhesive resin, but it is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 7 parts by mass relative to 100 parts by mass of the adhesive resin having functional groups. And more preferably 0.05 to 5 parts by mass.

<Adhesion imparting agent> 中 In this embodiment, from the viewpoint of further improving the adhesive force, the adhesive composition is better and further contains an adhesion imparting agent. In the present specification, the "adhesive imparting agent" refers to a component that assists in improving the adhesion of the above-mentioned adhesive resin, and refers to an oligomer having a mass average molecular weight (Mw) of less than 10,000, and is different from the above-mentioned adhesive resin. . The mass average molecular weight (Mw) of the tackifier is preferably 400 to 10,000, more preferably 500 to 8000, and still more preferably 800 to 5000.

Examples of the adhesion-imparting agent include, for example, C5 such as turpentine resin, terpene resin, styrene resin, pentene produced by thermal decomposition of petroleum brain, isoprene, piperine, and 1,3-pentadiene. C5 based petroleum resins obtained by copolymerization of fractions, C9 based petroleum resins obtained by copolymerization of C9 fractions such as indene, vinyltoluene, etc. produced by thermal decomposition of petroleum brain, and hydrogenated resins such as those hydrogenated.

The softening point of the adhesion-imparting agent is preferably 60 to 170 ° C, more preferably 65 to 160 ° C, and even more preferably 70 to 150 ° C. In this specification, the "softening point" of the adhesion-imparting agent refers to a value measured in accordance with JIS K 2531. The adhesion-imparting agent can be used alone or in combination of two or more different softening points and structures. When two or more types of plural adhesion-imparting agents are used, the weighted average of the softening points of the plural adhesion-imparting agents preferably falls within the above range.

The content of the adhesion-imparting agent is preferably 0.01 to 65% by mass, more preferably 0.05 to 55% by mass, and still more preferably 0.1 to 50% by mass, relative to the total amount (100% by mass) of the active ingredient in the adhesive composition. More preferably, it is 0.5 to 45% by mass, and still more preferably 1.0 to 40% by mass.

<Photopolymerization initiator> 时 In the present embodiment, when the adhesive composition contains an energy ray-curable adhesive resin as the adhesive resin, it is preferable to further contain a photopolymerization initiator. By forming an adhesive composition containing an energy ray-curable adhesive resin and a photopolymerization initiator, the adhesive layer formed from the adhesive composition can be sufficiently irradiated even with relatively low energy energy rays. The hardening reaction can adjust the adhesion to the desired range. In addition, as the photopolymerization initiator, for example, the same as those formulated in the solventless resin composition (y1).

The content of the photopolymerization initiator is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 5 parts by mass, and still more preferably 0.05 to 2 parts by mass with respect to 100 parts by mass of the energy ray-curable adhesive resin.

<Additives for Adhesives> 中 In this embodiment, the adhesive composition of the material for forming the adhesive layer does not impair the effects of the present invention. In addition to the additives described above, the adhesives used for general adhesives may also be included. With additives. Examples of the additives for the adhesive include antioxidants, softeners (plasticizers), rust inhibitors, pigments, dyes, retarders, reaction accelerators (catalysts), and ultraviolet absorbers. In addition, each of these adhesive additives can be used alone or in combination of two or more.

When such an additive for an adhesive is contained, the content of each additive for the adhesive is preferably 0.0001 to 20 parts by mass, and more preferably 0.001 to 10 parts by mass relative to 100 parts by mass of the adhesive resin.

The pressure-sensitive adhesive composition of the material for forming the pressure-sensitive adhesive layer may contain swellable particles as long as the effect of the present invention is not impaired. However, as described above, the adhesive layer included in the adhesive sheet of this embodiment is preferably a non-swellable adhesive layer. Therefore, it is better that the content of the expandable particles in the adhesive composition of the material forming the adhesive layer is reduced as much as possible. The content of the swellable particles is preferably less than 5% by mass, more preferably less than 1% by mass, and even more preferably less than 0.1% by mass, relative to the total amount (100% by mass) of the active ingredient of the adhesive composition. More preferably, it is less than 0.01% by mass, and particularly preferably, it is less than 0.001% by mass.

(Release material) As shown in the adhesive sheet 10a of FIG. 1 (B), the adhesive sheet of this embodiment may have a release material on the adhesive surface of the adhesive layer. (2) As a release material, a release sheet with a double-sided release treatment or a release sheet with a single-side release treatment is used, and examples include a case where a release agent is applied to a substrate for the release material.

Examples of the substrate for the release material include papers such as fine paper, cellophane, and kraft paper; polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate Polyester resin films such as resin, plastic films such as olefin resin films such as polypropylene resin and polyethylene resin; etc.

Examples of the release agent include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins, long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins. .

The thickness of the release material is not particularly limited, but is preferably 10 to 200 μm, more preferably 25 to 170 μm, and still more preferably 35 to 80 μm.

[Manufacturing method of adhesive sheet] The manufacturing method of the adhesive sheet of this embodiment is not particularly limited, and it is exemplified by the manufacturing method (a) having the following steps (1a) and (2a).・ Step (1a): The resin composition (y) of the forming material of the expandable substrate is coated on the release-treated surface of the release material to form a coating film, and the coating film is dried or UV-cured to form an expandable substrate. The steps.步骤 Step (2a): A step of forming a coating film by applying an adhesive composition of an adhesive layer-forming material on the surface of the aforementioned swellable substrate, and drying the coating film to form an adhesive layer.

Moreover, as another example of the manufacturing method of the adhesive sheet of this embodiment, the manufacturing method (b) which has the following steps (1b)-(3b) is illustrated.・ Step (1b): The resin composition (y) of the forming material of the expandable substrate is coated on the release-treated surface of the release material to form a coating film, and the coating film is dried or UV-cured to form an expandable substrate. The steps. (2) Step (2b): A step of applying a pressure-sensitive adhesive composition of an adhesive layer forming material to a coating film on a release-treated surface of a release material, and drying the coating film to form an adhesive layer.步骤 Step (3b): a step of bonding the surface of the aforementioned expandable substrate formed in step (1b) to the surface of the adhesive layer formed in step (2b).

In the above-mentioned production methods (a) and (b), the resin composition (y) and the adhesive composition may be further prepared by diluting a solvent to form a solution. Examples of the coating method include a spin coating method, a spray coating method, a bar coating method, a doctor blade coating method, a roll coating method, a blade coating method, a die coating method, and a gravure coating method.

In addition, the drying or UV irradiation of the coating film-forming expandable substrate from step (1a) of manufacturing method (a) and step (1b) of manufacturing method (b) is preferably performed by appropriately selecting conditions that do not expand the expandable particles. . For example, when the resin composition (y) containing thermally expandable particles is dried to form an expandable substrate, it is preferably carried out at a temperature below the expansion start temperature (t) of the thermally expandable particles.

<The steps of manufacturing the semiconductor device of the present embodiment> Next, the steps of the method of manufacturing the semiconductor device of the present embodiment will be described.方法 The method for manufacturing a semiconductor device according to this embodiment is a method for manufacturing a semiconductor device using the aforementioned adhesive sheet, and has the following steps (1) to (4). Step (1): a step of attaching a frame member having an opening portion to an adhesive surface of an adhesive layer; step (2): placing a semiconductor wafer on the adhesive layer exposed at the opening portion of the frame member A step of a part of the adhesive surface; step (3): covering the semiconductor wafer, the frame member, and the peripheral portion of the semiconductor wafer on the adhesive surface with the adhesive layer with a sealing material, and curing the sealing material to obtain A step of curing the sealed body in which the semiconductor wafer is sealed with a curing sealing material; (4) a step of expanding the expandable particles and peeling the adhesive sheet from the cured seal; Hereinafter, each step of the method for manufacturing a semiconductor device according to this embodiment will be described with reference to the drawings.

(Step (1)) FIG. 2 (A) is a cross-sectional view illustrating step (1) of bonding the frame member 20 having the opening 21 formed on the adhesive surface 12 a of the adhesive layer 12 of the adhesive sheet 10. When the pressure-sensitive adhesive sheet 10 includes the release material 13, the release material 13 is peeled in advance.

The frame member 20 is formed in a lattice shape and has a plurality of openings 21. The frame member 20 is preferably formed of a material having heat resistance. Examples of the material of the frame member 20 include metals such as copper, stainless steel, and 42 alloy; polyimide resin, polyacetal resin, polyimide resin, polycarbonate resin, modified polyphenylene ether resin, and polyparaphenylene Butyl dicarboxylate resins are resins called engineering plastics; glass epoxy resins and other composite materials. The thickness t _FR of the frame member 20 is, for example, 100 μm to 3 mm, preferably 100 μm to 1 mm, and more preferably 100 to 500 μm. If the thickness t _{FR of the} frame member 20 is 100 μm or more, warping of the semiconductor package can be suppressed even when a relatively wide area is sealed. If the thickness t _{FR of the} frame member 20 is 3 mm or less, it is possible to prevent a decrease in productivity of a manufacturing process of a semiconductor device. The opening 21 is a hole penetrating the front and back surfaces of the frame member 20. The shape of the opening 21 is not particularly limited as long as the semiconductor wafer CP can be housed in a frame. The depth of the hole in the opening 21 is not particularly limited as long as it can accommodate the semiconductor wafer CP. In the present embodiment, the frame member 20 is one having a plurality of openings 21, but a frame member having one opening may be used when the purpose of the present invention is achieved. The frame member 20 is preferably one in which a plurality of semiconductor wafers CP can be arranged in a matrix state with a plurality of rows and a plurality of rows arranged at a certain interval on the adhesive surface 12a.

(Step (2)) FIG. 2 (B) is a sectional view illustrating a step (2) of mounting the semiconductor wafer CP on a part of the adhesive surface 12a of the adhesive layer 12 exposed on the opening 21 of the frame member 20. As the semiconductor wafer CP, a conventionally known one can be used. The semiconductor wafer CP is formed on its circuit surface W1 as an integrated circuit composed of circuit elements such as a transistor, a resistor, and a capacitor. The semiconductor wafer CP is mounted such that the circuit surface W1 thereof is covered by the adhesive surface 12a. The semiconductor wafer CP can be mounted using a conventional device such as a flip chip bonding machine, a die bonding machine, and the like.配置 The layout and number of semiconductor chip CPs need only be appropriately determined according to the intended package form and production number. Here, the manufacturing method of the semiconductor device of this embodiment mode is to cover a semiconductor wafer CP such as FOWLP, FOPLP, etc. in a region larger than the wafer size with a sealing material, and can be applied to not only the circuit surface of the semiconductor wafer CP W1 also forms a rewiring layer package on the surface area of the sealing material. Therefore, the semiconductor wafer CP is placed on a part of the adhesive surface 12a of the adhesive layer 12 exposed from the opening 21 of the frame member 20, and the semiconductor wafer CP is preferably vacated with the frame member 20 surrounding the semiconductor wafer CP. Placed at regular intervals. The distance between the semiconductor wafer CP and the frame member 20 may be appropriately determined according to the intended packaging form and the like. (2) The semiconductor wafer CP forms a peripheral portion 30 of the semiconductor wafer CP in the adhesive surface 12 a of the adhesive layer 12 by being placed on a part of the adhesive surface 12 a of the adhesive layer 12 exposed from the opening 21 of the frame member 20. In FIG. 2 (B), the peripheral portion 30 of the semiconductor wafer CP is an adhesive surface 12 a corresponding to the adhesive layer 12 between the semiconductor wafer CP and the frame member 20.

(Step (3)) In FIGS. 2 (C) and (D), the peripheral portion 30 of the semiconductor wafer CP described in the semiconductor wafer CP, the frame member 20, and the adhesive surface 12a of the adhesive layer 12 is illustrated with a sealing material 40. A cross-sectional view of step (3) of covering and curing the sealing material 40 to obtain a cured sealing body 50 in which the semiconductor wafer CP is sealed with the curing sealing material 41. In the following, the step of covering the semiconductor wafer CP, the frame member 20, and the peripheral portion 30 of the semiconductor wafer CP in the adhesive surface 12a with the adhesive layer 12 with the sealing material 40 is sometimes referred to as a "coating step", The step of curing the sealing material 40 to obtain a cured sealing body 50 in which the semiconductor wafer CP is sealed with the curing sealing material 41 is referred to as a "curing step".

As shown in FIG. 2 (C), in the coating step, the semiconductor wafer CP, the frame member 20, and the peripheral portion 30 of the semiconductor wafer CP in the adhesive surface 12a with the adhesive layer 12 are covered with a sealing material 40. The sealing material 40 covers the entire exposed surface of the semiconductor wafer CP and the frame member 20, and also fills the gap between the semiconductor wafer CP and the frame member 20.

The sealing material 40 has a function of protecting the semiconductor wafer CP and its accompanying elements from the external environment. The sealing material 40 is not particularly limited, and it can be appropriately selected and used from among conventional users of semiconductor sealing materials. From the viewpoints of mechanical strength, heat resistance, insulation, and the like, the sealing material 40 is a hardening material, and examples thereof include a thermosetting resin composition, an energy ray hardening resin composition, and the like. Hereinafter, in this embodiment, a case where the sealing material 40 is a thermosetting resin composition will be described.

Examples of the thermosetting resin contained in the thermosetting resin composition of the sealing material 40 are, for example, epoxy resin, phenol resin, cyanate resin, etc., but from the viewpoints of mechanical strength, heat resistance, insulation, moldability, and the like , Preferably epoxy resin. The thermosetting resin composition may contain, in addition to the thermosetting resin, a hardener such as a phenol resin-based hardener, an amine-based hardener, a hardening accelerator, an inorganic filler such as silicon oxide, etc., as necessary. Additives such as elastomers. The sealing material 40 may be solid or liquid at room temperature. In addition, the form of the sealing material 40 that is solid at room temperature is not particularly limited, and may be, for example, granular, flake, or the like.

As a method of covering the semiconductor wafer CP, its peripheral portion 30, and the frame member 20 with the sealing material 40, any method can be appropriately selected and used from the conventional methods used for semiconductor packaging steps. For example, a roll layer method and a vacuum application method can be applied. Press method, vacuum layer method, spin coating method, nozzle coating method, transfer injection molding method, compression molding method, etc. In these methods, in order to improve the filling property of the sealing material 40, the sealing material 40 is heated to provide fluidity during coating.

As shown in FIG. 2 (D), after the coating step is performed, the sealing material 40 is hardened to obtain a hardened sealing body 50 that seals the semiconductor wafer CP with the hardened sealing material 41. Herein, as described above, the adhesive sheet 10 used in the present embodiment is one which contains expandable particles that are expanded by heat, energy rays, and the like. In step (4) described later, the expandable particles are expanded to make the adhesive. The adhesion between the surface 12 a and the hardened sealing body 50 is reduced, and the adhesive sheet 10 is peeled from the hardened sealing body 50. Therefore, in the coating step and the hardening step, it is preferable to appropriately select conditions that do not expand the expandable particles, and to cover the sealing material 40 and harden. For example, when the expandable particles contained in the adhesive sheet 10 are thermally expandable particles, the heating conditions (heating temperature and heating time) in the coating step and the hardening step are preferably the adhesive sheet 10 caused by the expansion of the thermally expandable particles. The heating condition of the thickness increase rate of 10% or less, the heating condition of the aforementioned increase rate of 5% or less, and the heating condition of the aforementioned increase rate of 0% (that is, the heating without expanding the thermally expandable particles) condition). The thickness increase rate of the adhesive sheet 10 can be measured, for example, in accordance with JIS K6783, Z1702, Z1709 using a constant pressure thickness measuring device (manufactured by TECLOCK Co., Ltd., product name "PG-02") before and after heating under specific conditions. The thickness of the sheet 10 is calculated based on the following formula. Thickness increase rate (%) = (thickness after heating-thickness before heating) × 100 / thickness before heating. The coating step and hardening step can be implemented individually, but it can also be used to heat the sealing material 40 in the coating step. This heating directly hardens the sealing material 40. That is, in this case, the coating step and the hardening step may be performed simultaneously.

In this embodiment, a description is given of a case in which a thermosetting resin composition is used as the sealing material 40 and heat-expandable particles are used as the expandable particles. However, for example, the sealing material 40 may be an energy-ray-curable resin composition. In the case where the expandable particles are thermally expandable particles, the sealing material 40 may be an energy ray-curable resin composition, and the expandable particles are energy ray expandable particles. In these aspects, the coating step and The thickness increase rate of the adhesive sheet 10 in the hardening step all satisfies the aforementioned range.

Although specific examples of the temperature of the heat-curable resin composition in the coating step may vary depending on the type of the sealing material 40 used and the type of the expandable particles, the temperature may be, for example, 30 to 180 ° C., and preferably 50 to 170. The temperature is preferably 70 to 150 ° C. The heating time is, for example, 5 seconds to 60 minutes, preferably 10 seconds to 45 minutes, and more preferably 15 seconds to 30 minutes. (2) When the thermosetting resin composition is pressed in the coating step, the pressing force is, for example, 0.1 to 2.0 MPa, more preferably 0.2 to 1.8 MPa, and still more preferably 0.3 to 1.6 MPa.时 When the thermosetting resin composition is pressed while reducing pressure in the coating step, the pressure is, for example, 0.1 to 5.0 MPa, and more preferably 0.5 to 4.0 MPa. Although the specific example of the temperature at which the sealing material 40 is hardened in the aforementioned hardening step varies depending on the type of the sealing material 40 used, the type of the expandable particles, etc., it may be, for example, 80 to 240 ° C, preferably 90 to 200 ° C. , More preferably 100 to 170 ° C. The heating time is, for example, 10 to 180 minutes, preferably 20 to 150 minutes, and more preferably 30 to 120 minutes.

In this embodiment, it is preferable to perform a coating step and a hardening step using a sheet-shaped sealing material (hereinafter also referred to as a "sheet-shaped sealing material"). In the method using a sheet-shaped sealing material, the sheet-shaped sealing material is placed so as to cover the semiconductor wafer CP and its peripheral portion 30 and the frame member 20, and the semiconductor wafer CP and its peripheral portion 30 and the frame member 20 are covered with the sealing material 40. . At this time, it is preferable that the portion where the gap between the semiconductor wafer CP and the frame member 20 is not filled with the sealing material 40 is generated by a vacuum laminator while being appropriately decompressed, heated and pressed. The preferable conditions of the reduced pressure, heating and pressing conditions are as described above. Subsequently, the laminated sealing material 40 is heat-hardened. The preferable aspect of the hardening temperature is as described above. (2) The sheet-shaped sealing material may be a laminated sheet supported by a resin sheet such as polyethylene terephthalate. In this case, after the laminated sheet is placed so that the sheet-shaped sealing material covers the semiconductor wafer CP and its peripheral portion 30 and the frame member 20, the resin sheet is peeled from the sealing material. When a sheet-shaped sealing material is used, after the sheet-shaped sealing material is laminated, the first heating and pressing step may be performed before the heat curing step. In this first heating and pressing step, the semiconductor wafer CP and the adhesive sheet 10 coated with the sealing material 40 are sandwiched by plate-shaped members from both sides, and are pressed under the conditions of a specific temperature, time, and pressure. By performing the first heating and pressing step, the gap between the semiconductor wafer CP and the frame member 20 is also easily filled with the sealing material 40. Furthermore, by performing the first heating and pressing step, the unevenness of the sealing material layer made of the sealing material 40 can also be flattened. As the plate-shaped member, a metal plate such as stainless steel can be used.

In step (3), a hardened sealing body 50 in which a plurality of semiconductor wafers CP are embedded in the hardened sealing material 41 is obtained. Furthermore, in steps (4) and (5) described later, after the adhesive sheet 10 is peeled from the hardened sealing body 50, a step of forming a rewiring layer is performed on the exposed surface. In order to improve the rationality of the hardened sealing body 50 in these steps, if necessary, a reinforcing member may be pasted on the exposed surface of the hardened sealing body 50 (that is, the surface opposite to the expandable substrate). The reinforcing member is not particularly limited, but for example, a reinforcing plate having excellent heat resistance such as glass epoxy resin is preferable, and the reinforcing plate is preferably bonded to the entire surface of the exposed surface of the hardened and sealed body 50. The reinforcing member may be bonded via, for example, an adhesive layer. Since the reinforcing member is removed after fulfilling its purpose, the adhesive layer is preferably one that can be fixed and peeled as required. For the bonding of the reinforcing member, for example, a bonding layer having a thermosetting property and a reinforcing plate may be sequentially laminated on the exposed surface of the hardened sealing body 50. Then, as needed, the two surfaces of the reinforcing plate side and the adhesive sheet side are respectively plated. The second heating and pressurizing step is carried out by sandwiching the shaped member and pressurizing under the conditions of a specific temperature, time, and pressure. In the second heating and pressing step, a metal plate such as stainless steel can also be used as the plate-like member.

(Step (4)) Fig. 2 (E) is a cross-sectional view illustrating step (4) in which the expandable particles expand and the adhesive sheet 10 is peeled from the hardened sealing body 50. Specifically, according to the type, the expandable particles expand by heat, energy rays, etc., and form irregularities on the adhesive surface 12a of the adhesive layer 12, thereby reducing the adhesive force between the adhesive surface 12a and the hardened sealing body 50. And the adhesive sheet 10 is peeled. (4) Step 4 is preferably performed in a state of a surface 11 a of the fixing base 11, such as a fixing jig, on the side opposite to the adhesive layer 12. With the fixed surface 11a, when the expandable particles are expanded, unevenness can be prevented from being formed on the surface 11a side, so that unevenness can be efficiently formed on the adhesive surface 12a side of the adhesive layer 12, and more excellent peelability can be obtained. (2) As shown in FIG. 2 (E), in this embodiment, as the aforementioned fixing jig, an adsorption table 90 having a plurality of adsorption holes 91 is used to fix the surface 11a of the adhesive sheet 10. The adsorption table 90 includes a pressure reducing mechanism such as a vacuum pump, and the object is fixed to the adsorption surface by using the pressure reducing mechanism to adsorb the object from the plurality of adsorption holes 91.

The method for suppressing unevenness on the surface 11a side of the substrate 11 is not limited to the above method, and any method for physically suppressing unevenness on the surface 11a side of the substrate 11 can be adopted. As an example, a method of bonding a hard support to the surface 11a via, for example, an arbitrary adhesive layer, a double-sided adhesive sheet, or the like. The material of the rigid support can be determined as appropriate in consideration of mechanical strength and heat resistance. Examples include metal materials such as SUS; non-metallic inorganic materials such as glass and silicon wafers; polyimide, polyimide Resin materials such as amines; composite materials such as glass epoxy resins. The thickness of the rigid support may be appropriately determined in consideration of mechanical strength, handleability, and the like, and is, for example, 100 μm to 50 mm. (2) The adhesive layer (hereinafter also referred to as a "second adhesive layer") used for bonding the rigid support is not particularly limited, but may be formed using an adhesive composition for forming the adhesive layer 12. The second adhesive layer may be provided on the surface 11 a side of the substrate 11 in advance. In this case, a release material may be further provided on the adhesive surface of the second adhesive layer. That is, the adhesive sheet 10 may have a configuration of the adhesive layer 12 / base material 11 / second adhesive layer, or may have a release material / adhesive layer 12 / base material 11 / second adhesive layer / release material. Make up.

The method of expanding the expandable particles may be appropriately selected depending on the type of the expandable particles. (2) When the expandable particles are thermally expandable particles, they may be heated to a temperature equal to or higher than the expansion start temperature (t). Here, the "temperature above the expansion start temperature (t)" is preferably "the expansion start temperature (t) + 10 ° C" or more and the "expansion start temperature (t) + 60 ° C" or less, and more preferably the "expansion start temperature" (t) + 15 ° C "or more" Expansion start temperature (t) + 40 ° C "or less. Specifically, depending on the type of the heat-expandable particles, it may be heated to expand in a range of, for example, 120 to 250 ° C.

After the expandable particles expand, the adhesive sheet 10 is peeled from the hardened sealing body 50. Since the adhesive sheet 10 of this embodiment has excellent peelability, it can be peeled with a smaller external force than the conventional temporary fixing sheet. The peeling method is not particularly limited, but examples include a method of peeling using a tape remover.

In the manufacturing method of this embodiment, in step (4), before or after peeling the adhesive sheet 10 from the hardened sealing body 50, if necessary, the method may further include grinding the hardened sealing body 50 to reduce the thickness of the hardened sealing body 50, and grinding the hardened seal. The step of the body 50 on the side opposite to the redistribution layer forming surface.

(Step (5)) The manufacturing method of this embodiment preferably includes a step (5) of forming a rewiring layer on the hardened sealing body 50 of the peeled double-sided adhesive sheet 10. (FIG. 3 (A) shows a cross-sectional view of the cured sealing body 50 after the adhesive sheet 10 is peeled off. (2) In this step, rewiring is formed on the circuit surface W1 and on the surface 50a of the hardened sealing body 50 outside the area corresponding to the semiconductor wafer CP to be connected to the exposed circuits W2 of the semiconductor wafer CP.

FIG. 3 (B) is a cross-sectional view illustrating a step of forming the first insulating layer 61 on the circuit surface W1 of the semiconductor wafer CP and the surface 50 a of the hardened sealing body 50. (1) The first insulating layer 61 containing an insulating resin is formed on the circuit surface W1 and the surface 50a so that the internal terminal electrode W3 of the circuit W2 or the circuit W2 of the semiconductor wafer CP is exposed. Examples of the insulating resin include polyimide resin, polybenzoxazole resin, and silicone resin. The material of the internal terminal electrode W3 is not limited as long as it is a conductive material, and examples thereof include metals such as gold, silver, copper, and aluminum, and alloys including these metals.

FIG. 3 (C) is a cross-sectional view illustrating a step of forming a rewiring 70 electrically connected to the semiconductor wafer CP sealed with the hardened sealing body 50. In this embodiment, the rewiring 70 is formed after the formation of the first insulating layer 61. The material of the rewiring 70 is not limited as long as it is a conductive material, and examples thereof include metals such as gold, silver, copper, and aluminum, and alloys including these metals. The rewiring 70 can be formed by a conventional method such as a removal method or a semi-additive method.

FIG. 4 (A) is a sectional view showing a step of forming the second insulating layer 62 of the covered rewiring 70. The rewiring 70 has an external electrode pad 70A for external terminal electrodes. An opening or the like is provided in the second insulating layer 62 to expose an external electrode pad 70A for an external terminal electrode. In this embodiment, the external electrode pad 70A is exposed in the region (the region corresponding to the circuit surface W1) and outside the region (the region corresponding to the surface 50a on the cured sealing body 50) of the semiconductor wafer CP of the cured sealing body 50. The rewiring 70 is formed on the surface 50 a of the hardened and sealed body 50 such that the external electrode pads 70A are arranged in an array. In this embodiment, since the external electrode pad 70A has a structure exposed outside the region of the semiconductor wafer CP of the hardened sealing body 50, FOWLP or FOPLP can be obtained.

(Connection step with external terminal electrode) FIG. 4 (B) is a cross-sectional view showing a step of connecting the external terminal electrode 80 to the external electrode pad 70A. An external terminal electrode 80 such as a solder ball is placed on the external electrode pad 70A exposed from the second insulating layer 62, and the external terminal electrode 80 and the external electrode pad 70A are electrically connected by soldering or the like. The material of the solder ball is not particularly limited, and examples include lead-containing solder and lead-free solder.

(Cutting step) FIG. 4 (C) is a cross-sectional view illustrating a step of singulating the hardened sealing body 50 to which the external terminal electrode 80 is connected. In this step, the hardened sealing body 50 is singulated in units of a semiconductor wafer CP. The method of singulating the hardened sealing body 50 is not particularly limited, and can be performed by a cutting means such as a dicing saw. (2) The semiconductor device 100 in the unit of a semiconductor wafer CP is manufactured by singulating the cured sealing body 50. As described above, the semiconductor device 100 having the external terminal electrode 80 connected to the external electrode pad 70A outside the area fanned out to the semiconductor wafer CP is manufactured as FOWLP, FOPLP, or the like.

(Mounting Step) The present embodiment preferably includes a step of mounting the single-chip semiconductor device 100 on a printed wiring board or the like. [Example]

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

<Mass average molecular weight (Mw)> 测定 Measured under the following conditions using a gel permeation chromatography device (manufactured by TOSOH Co., Ltd., product name "HLC-8020"), using values measured in terms of standard polystyrene conversion. (Measurement conditions) 管 Columns: "TSK protection column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", and "TSK gel G1000HXL" (all manufactured by TOSOH Corporation) are connected in order. • Column temperature: 40 ° C 展开 • Development solvent: Tetrahydrofuran 流速 • Flow rate: 1.0mL / min

<Measurement of Thickness of Each Layer> 测定 Measured using a constant pressure thickness measuring device (model: "PG-02J", standard specification: JIS K6783, Z1702, Z1709) manufactured by TECLOCK Corporation.

<Average particle diameter (D ₅₀ ), 90% particle diameter (D ₉₀ ) of thermally expandable particles> Using a laser diffraction particle size distribution measuring device (for example, product name "Mastersizer 3000" manufactured by Malvern), measured at 23 ° C. Particle distribution of thermally expandable particles before expansion. Next, the particle diameters whose cumulative volume frequency is 50% and 90% calculated from the smaller particle diameters are set as "average particle diameter of thermally expandable particles (D ₅₀ )" and "average particle diameter of thermally expandable particles" 90% particle size (D ₉₀ ) ".

<Storage modulus E 'of the expandable substrate> When the measurement object is a non-adhesive expandable substrate, the expandable substrate is made into a size of 5 mm in length × 30 mm in width × 200 μm in thickness. Test samples. Using a dynamic viscoelasticity measuring device (manufactured by TA Instrument, product name "DMAQ800"), specific conditions were measured under conditions of a test start temperature of 0 ° C, a test end temperature of 300 ° C, a temperature increase rate of 3 ° C / min, a vibration number of 1 Hz, and an amplitude of 20 μm. The storage modulus E 'of the test sample at temperature.

<Shear storage modulus G 'of the adhesive layer and storage modulus E' of the expansive adhesive layer> When the measurement object is an expansive adhesive layer and an adhesive layer having adhesiveness, the expansive adhesive The layer and the adhesive layer were prepared to have a diameter of 8 mm × thickness of 3 mm, and the peeled material was removed as a test sample. Using a viscoelasticity measuring device (manufactured by Anton Paar, device name "MCR300"), the conditions of a test start temperature of 0 ° C, a test end temperature of 300 ° C, a temperature increase rate of 3 ° C / min, and a vibration frequency of 1Hz were performed by a twist-shear method The shear storage modulus G 'of a test sample at a specific temperature is determined. Next, based on the measured value of the shear storage modulus G ', the value of the storage modulus E' is calculated from the approximate expression "E '= 3G'".

<Probe viscosity value> After cutting the expansive substrate or the expansive adhesive layer to be measured into a square of 10 mm on one side, it is left to stand in an environment of 23 ° C and 50% RH (relative humidity) for 24 hours. A lightly peeled film was removed as a test sample. The aforementioned test sample was measured at 23 ° C and 50% RH (relative humidity) using a TACKING tester (manufactured by Japan Special Instrument Co., Ltd., product name "NTS-4800"). The probe viscosity value of the surface of the test sample exposed by peeling the film. Specifically, a probe made of stainless steel with a diameter of 5 mm was brought into contact with the surface of the test sample at a contact load of 0.98 N / cm ² for 1 second, and then it was necessary to measure the probe at a speed of 10 mm / second to leave the surface of the test sample. force. Then, the measured value is used as the probe viscosity of the test sample.

Details of the adhesive resin, additives, heat-expandable particles, and release materials used in the following production examples are as follows. <Adhesive Resin>-Acrylic copolymer (i): contains raw materials derived from 2-ethylhexyl acrylate (2EHA) / 2-hydroxyethyl acrylate (HEA) = 80.0 / 20.0 (mass ratio) A solution of an acrylic copolymer having a mass average molecular weight (Mw) of 600,000 constituting units of the monomer. Diluted solvent: ethyl acetate, solid content concentration: 40% by mass.・ Acrylic copolymer (ii): containing n-butyl acrylate (BA) / methyl methacrylate (MMA) / 2-hydroxyethyl acrylate (HEA) / acrylic acid = 86.0 / 8.0 / 5.0 / 1.0 ( Mass ratio) A solution of an acrylic copolymer having a mass average molecular weight (Mw) of 600,000 constituting units of the raw material monomers. Diluted solvent: ethyl acetate, solid content concentration: 40% by mass. <Additives>-Isocyanate crosslinking agent (i): manufactured by TOSOH Corporation, product name "Coronate L", solid content concentration: 75% by mass. -Photopolymerization initiator (i): manufactured by BASF, product name "IRGACURE 184", 1-hydroxy-cyclohexyl-phenyl ketone. <Thermally expandable particles> ・ Thermally expandable particles (i): Product name "S2640" manufactured by Kuraray Co., Ltd., expansion start temperature (t) = 208 ° C, average particle diameter (D ₅₀ ) = 24 μm, 90% particle diameter D ₉₀ ) = 49 μm. <Release material> ・ Heavy release film: manufactured by LINTEK Corporation, product name "SP-PET382150", a silicone terephthalate (PET) film is provided on one side with a silicone-based release agent For the release agent layer, the thickness is 38 μm.・ Light release film: manufactured by LINTEK Co., Ltd. under the product name "SP-PET381031". One side of the PET film is provided with a release agent layer made of a silicone-based release agent. Thickness: 38 μm.

Production Example 1 (Formation of Adhesive Layer (X)) In 100 parts by mass of the solid content of the acrylic copolymer (i) of the adhesive resin, 5.0 parts by mass of the isocyanate-based crosslinking agent (i) (solid content) Ratio), diluted with toluene and uniformly stirred to prepare a composition (x-1) having a solid content concentration (active ingredient concentration) of 25% by mass. Next, the prepared composition (x-1) was coated on the surface of the release agent layer of the heavy release film to form a coating film, and the coating film was dried at 100 ° C. for 60 seconds to form an adhesive layer having a thickness of 10 μm ( X). The shear storage modulus G '(23) of the adhesive layer (X) at 23 ° C was 2.5 × 10 ⁵ Pa.

Production Example 2 (Formation of Swellable Substrate (Y-1)) (1) Composition (y-1) was prepared from terminal isocyanate amine obtained by reacting an ester diol with isophorone diisocyanate (IPDI) The formate prepolymer reacts with 2-hydroxyethyl acrylate to obtain a bifunctional acrylic urethane-based oligomer having a mass average molecular weight (Mw) of 5,000. Next, 40% by mass (solid content ratio) of isobornyl acrylate (IBXA) as an energy ray polymerizable monomer is prepared in 40% by mass (solid content ratio) of the acrylic urethane-based oligomer synthesized above. And 20% by mass (solid content ratio) of phenylhydroxypropyl acrylate (HPPA), 100 parts by mass of the total amount of the acrylic urethane-based oligomer and the energy ray polymerizable monomer, and further formulated as photopolymerization 2.0 parts by mass (solid content ratio) of 1-hydroxycyclohexylphenyl ketone (manufactured by BASF, product name "IRGACURE 184") and 0.2 parts by mass (solid content ratio) of phthalocyanine pigment as an additive to adjust energy Wire-curable composition. Next, the heat-expandable particles (i) are blended in the energy ray-curable composition to prepare a solvent-free composition (y-1) containing no solvent. In addition, the content of the thermally expandable particles (i) with respect to the total amount (100% by mass) of the composition (y-1) was 20% by mass.

(2) The expandable substrate (Y-1) is formed on the surface of the release agent layer of the light release film, and the prepared composition (y-1) is applied to form a coating film. Next, using an ultraviolet irradiation device (manufactured by EYEGRAPHICS Corporation, product name "ECS-401GX") and a high-pressure mercury lamp (manufactured by EYEGRAPHICS Corporation, product name "H04-L41"), the conditions were as follows: an illumination intensity of 160 mW / cm ² and a light amount of 500 mJ / cm ² The coating film was hardened by irradiating ultraviolet rays to form an expandable substrate (Y-1) having a thickness of 50 μm. In addition, the said illuminance and light quantity at the time of ultraviolet irradiation are the values measured using the illuminance and light quantity meter (made by EIT company, product name "UV Power Puck II").

Production Example 3 (Formation of Swellable Substrate (Y-2)) (1) Synthesis of Urethane Prepolymer In a reaction vessel under a nitrogen atmosphere, a carbonate having a mass average molecular weight (Mw) of 1,000 100 parts by mass (solid content ratio) of an isophorone diisocyanate, and isophorone diisocyanate is formulated so that the equivalent ratio of the hydroxyl group of the carbonate diol to the isocyanate group of isophorone diisocyanate (IPDI) becomes 1/1, Further, 160 parts by mass of toluene was added, and the reaction was performed at 80 ° C. for more than 6 hours under stirring in a nitrogen environment until the isocyanate group concentration reached a theoretical amount. Next, a solution of 1.44 parts by mass (solid content ratio) of 2-ethylhexyl methacrylate (2-HEMA) diluted in 30 parts by mass of toluene was added, and further reacted at 80 ° C for 6 hours until the isocyanate groups at both ends disappeared. A urethane prepolymer having a mass average molecular weight (Mw) of 29,000 was obtained.

(2) Synthesis of acrylic urethane resin In a reaction vessel under a nitrogen atmosphere, 100 parts by mass of the urethane prepolymer obtained in (1) (solid content ratio) and methyl methacrylate were added. 117 parts by mass (solid content), 5.1 parts by mass of 2-ethylhexyl acrylate (2-HEMA) (solid content), 1.1 parts by mass of 1-thioglycol (solid content), and toluene 50 parts by mass, the temperature was raised to 105 ° C while stirring. Next, in a reaction container, a solution of 2.2 parts by mass (solid content ratio) of a radical initiator (manufactured by Japan Finechem Co., Ltd., "ABN-E") was diluted with 210 parts by mass of toluene, and maintained at 105. The state at ℃ was added dropwise over 4 hours. After the completion of the dropwise addition, the mixture was reacted at 105 ° C. for 6 hours to obtain a solution of an acrylic urethane resin having a mass average molecular weight (Mw) of 105,000.

(3) Formation of swellable substrate (Y-2): 100 parts by mass of the solid content of the solution of the acrylic urethane resin obtained in the above (2), and 6.3 parts by mass of the isocyanate-based crosslinking agent (i) (Solid fraction), 1.4 parts by mass (solid fraction) of dioctyltinbis (2-ethylhexanoate) as a catalyst, and the thermally expandable particles (i), diluted with toluene, uniformly stirred, and prepared The composition (y-2) having a solid content concentration (active ingredient concentration) of 30% by mass. In addition, the content of the thermally expandable particles (i) with respect to the total amount (100% by mass) of the active ingredient in the obtained composition (y-2) was 20% by mass. Next, the prepared composition (y-2) was coated on the surface of the release agent layer of the light release film to form a coating film, and the coating film was dried at 100 ° C. for 120 seconds to form a 50 μm thick expandable substrate ( Y-2).

Production Example 4 (Formation of Intumescent Adhesive Layer (Y-3)) In 100 parts by mass of the solid content of the acrylic copolymer (ii) contained in an adhesive resin, 6.3 mass of the isocyanate-based crosslinking agent (i) was blended. (Solid content ratio) and the thermally expandable particles (i), diluted with toluene, and uniformly stirred to prepare a composition (y-3) having a solid content concentration (effective component concentration) of 30% by mass. In addition, the content of the thermally expandable particles (i) with respect to the entire amount (100% by mass) of the active ingredient in the obtained composition (y-3) was 20% by mass. Next, the prepared composition (y-3) was coated on the surface of the release agent layer of the light release film to form a coating film, and the coating film was dried at 100 ° C. for 120 seconds to form a 50 μm thick expandable adhesive layer. (Y-3).

The expandable base materials (Y-1) to (Y-2) formed in Production Examples 2 to 3 and the expandable adhesive layer (Y-3) formed in Production Example 4 were measured at 23 ° C based on the methods described above. Storage modulus E 'and probe viscosity at 100 ° C and 208 ° C of the expansion start temperature of the thermally expandable particles used. These results are shown in Table 1.

Example 1 The surface of the adhesive layer (X) formed in Production Example 1 and the surface of the expandable substrate (Y-1) formed in Production Example 2 were bonded to each other to produce a sequentially laminated light release film / expandable substrate ( Y-1) / adhesive layer (X) / adhesive sheet (1) of heavy release film.

Example 2 In the same manner as in Example 1 except that the intumescent substrate (Y-1) was replaced with the intumescent substrate (Y-2) formed in Production Example 3, a sequentially laminated light release film / expandable substrate was produced. (Y-2) / adhesive layer (X) / adhesive sheet (2) of the heavy release film.

Comparative Example 1 Except that the intumescent base material (Y-1) was replaced with the intumescent adhesive layer (Y-3) formed in Production Example 4, the same procedure as in Example 1 was followed to produce a laminated light release film / expandable adhesive. Agent layer (Y-3) / adhesive layer (X) / adhesive sheet (3) of heavy release film.

Comparative Example 2 The light release film / expandable adhesive layer (Y-3) formed in Production Example 4 was used as the adhesive sheet (4) as it was.

The following measurements were performed on the produced adhesive sheets (1) to (4). These results are shown in Table 2.

<Evaluation of the position shift of the semiconductor wafer during the sealing step> (1) The self-adhesive sheets (1) to (3) were peeled off from the heavy release film to expose the adhesive layer (X). On the adhesive surface of the adhesive layer (X) of the adhesive sheet (1) to (3) and the expandable adhesive layer (Y-3) of the adhesive sheet (4), a specific number of openings of 10 mm × 10 mm are attached. Part of the copper frame member. Next, the light release film is removed from the adhesive sheets (1) to (4), and the exposed expandable substrate or the expandable adhesive layer is fixed to the adsorption of an adsorption table having a plurality of adsorption holes as shown in FIG. 2 (E). Surface. Next, 9 semiconductor wafers (wafer size: 6.4 mm x 6.4 mm, wafer) are placed on the adhesive surface exposed by the plurality of openings in such a manner that the adhesive surface is in contact with the circuit surface of the semiconductor wafer with a necessary interval from the frame member. 200 μm thick (# 2000)). Subsequently, a sealing resin film (sealing material) was laminated on the adhesion surface, the frame member, and the semiconductor wafer, and a vacuum heating and pressure laminator ("7024HP5" manufactured by ROHM and HAAS) was used to cover the adhesion surface and the frame with the sealing material. A member and a semiconductor wafer are hardened, and a hardened sealing body is produced. The sealing conditions are as follows.・ Preheating temperature: 100 ° C for both table and partitions. Evacuation: 60 seconds. Dynamic pressing mode: 30 seconds. Static pressing mode: 10 seconds. Sealing temperature: 180 ° C. ℃ low temperature) · Sealing time: 60 minutes

After sealing, the adhesive sheets (1) to (4) are heated at 240 ° C above the expansion expansion temperature (208 ° C) of the thermally expandable particles for 3 minutes, and the hardened sealing body is separated from the adhesive sheets (1) to (4) to The semiconductor wafer on the surface (rewiring layer formation surface) of the separated hardened sealing body was observed visually and with a microscope, and the presence or absence of the positional deviation of the semiconductor wafer was confirmed. The evaluation was performed on the basis of the following criteria.・ A: No semiconductor wafer with a position deviation of 25 μm or more from the position before sealing was observed.・ F: It was confirmed that a semiconductor wafer with a position deviation of 25 μm or more from the position before sealing was generated.

<Evaluation of the surface flatness of the semiconductor wafer side after the sealing step> Use the adhesive sheets (1) to (4) to prepare a hardened sealing body in the same procedure as in the above-mentioned "evaluation of the position deviation of the semiconductor wafer during the sealing step", and Separated from the adhesive sheet. Using a contact-type surface roughness meter ("SV3000" manufactured by Mitutoyo Corporation), the step (rewiring layer formation surface) of each semiconductor wafer side of the produced hardened and sealed body was measured for step differences and evaluated based on the following criteria.・ A: A part where a step of 2 μm or more has not been confirmed.・ F: A part where a step of 2 μm or more is confirmed.

<Measurement of the adhesive force of the adhesive sheet before and after heating> The person who intends to remove the heavy peeling film of the adhesive sheets (1) to (3) and the adhesive sheet (4), respectively, the adhesive layer (X) or the expandable adhesive layer (Y -3) A stainless steel plate (SUS304 360 grinded) attached to an adherend, and left at room temperature for 24 hours at 23 ° C and 50% RH (relative humidity) as a test sample. Next, using the test sample described above, the adhesive force at 23 ° C was measured at 23 ° C and 50% RH (relative humidity) based on JIS Z0237: 2000 by a 180 ° peeling method at a tensile speed of 300 mm / min. . In addition, the test sample was heated on a hot plate at 240 ° C or higher for the expansion start temperature (208 ° C) of the thermally expandable particles for 3 minutes, and left to stand in a standard environment (23 ° C, 50% RH (relative humidity)). After 60 minutes, based on JIS Z0237: 2000, the adhesive force after heating above the expansion start temperature was measured at a stretching speed of 300 mm / min by a 180 ° peeling method. In addition, when it is difficult to measure the adhesive force when the stainless steel plate cannot be attached to the adherend, it is called "impossible measurement", and the adhesive force is 0 (N / 25mm).

As can be seen from Table 2, according to the manufacturing method using the adhesive sheets (1) and (2) of Examples 1 and 2, during the heating in the sealing step, the sinking effect of the semiconductor wafer was high, so no semiconductor wafer was seen. The position is shifted, and the surface (rewiring layer formation surface) on the semiconductor wafer side after the sealing step is also flat. In addition, although the adhesive sheets (1) and (2) had good adhesive force before heating, the adhesive force was reduced to an unmeasurable level after heating above the expansion starting temperature, so it was confirmed that it can be easily peeled off with a little force when peeling. The result.

On the other hand, the adhesive sheet (3) of Comparative Example 1 and the adhesive sheet (4) of Comparative Example 2 are not swellable substrates, and because they have a swellable adhesive layer, the semiconductor wafer may be heated during the sealing step. When sinking, the position of the semiconductor wafer was seen to be shifted, and a step was seen on the surface (rewiring layer formation surface) of the semiconductor wafer side after the sealing step. Therefore, it is considered to be unsuitable for use in the sealing step when manufacturing, for example, FOWLP and FOPLP.

10‧‧‧ double-sided adhesive sheet

11‧‧‧ Substrate

11a‧‧‧ surface

12‧‧‧ Adhesive layer

12a‧‧‧ Adhesive surface

13‧‧‧ peeling material

20‧‧‧Frame components

21‧‧‧ opening

30‧‧‧ Peripheral portion of the semiconductor wafer in the adhesive surface of the adhesive layer

40‧‧‧sealing material

41‧‧‧hardened sealing material

50‧‧‧hardened seal

50a‧‧‧ surface

61‧‧‧The first insulation layer

62‧‧‧Second insulation layer

70‧‧‧ rewiring

70A‧‧‧External electrode pad

80‧‧‧ external terminal electrode

90‧‧‧ Adsorption Station

91‧‧‧ adsorption hole

100‧‧‧ semiconductor device

CP‧‧‧Semiconductor wafer

W1‧‧‧Circuit Surface

W2‧‧‧Circuit

W3‧‧‧Internal terminal electrode

FIG. 1 is a cross-sectional view of an adhesive sheet showing an example of the configuration of the adhesive sheet in this embodiment. FIG. 2 is a cross-sectional view illustrating an example of a manufacturing method according to this embodiment. FIG. 3 is a cross-sectional view illustrating an example of the manufacturing method of the embodiment following FIG. 2. FIG. 4 is a cross-sectional view illustrating an example of the manufacturing method of the embodiment following FIG. 3.

Claims (11)

A method for manufacturing a semiconductor device, which is a method for manufacturing a semiconductor device using an adhesive sheet having an adhesive layer and a non-adhesive substrate containing expandable particles, and having the following steps (1) to (4), Step (1): a step of bonding a frame member having an opening portion to an adhesive surface of an adhesive layer; step (2): placing a semiconductor wafer on the exposed portion of the frame member A step of a part of the adhesive surface of the adhesive layer; step (3): covering the semiconductor wafer, the frame member, and the peripheral portion of the semiconductor wafer on the adhesive surface of the adhesive layer with a sealing material to seal the peripheral portion of the semiconductor wafer A step of obtaining a hardened sealed body in which the semiconductor wafer is sealed by a hardened sealing material; (4) a step of expanding the expandable particles and peeling the adhesive sheet from the hardened sealed body. The method for manufacturing a semiconductor device according to claim 1, further comprising the following steps (5) and (5): a step of forming a rewiring layer on the adhesive sheet as a peeled hardened sealing body. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the expandable particles are thermally expandable particles, and the step (4) is to heat the adhesive sheet to expand the thermally expandable particles to adhere the adhesive. The step of peeling the sheet from the hardened sealing body. The method for manufacturing a semiconductor device according to claim 3, wherein the expansion start temperature (t) of the thermally expandable particles is 120 to 250 ° C. The method for manufacturing a semiconductor device according to claim 4, wherein the substrate satisfies the following requirements (1) to (2), and requirement (1): the storage modulus E '(100 of the substrate at 100 ° C) ) Is 2.0 × 10 ⁵ Pa or more; Requirement (2): The storage modulus E ′ (t) of the substrate at the expansion start temperature (t) of the thermally expandable particles is 1.0 × 10 ⁷ Pa or less. The adhesive sheet according to any one of claims 1 to 5, wherein the average particle diameter of the expandable particles before expansion at 23 ° C is 3 to 100 µm. The method for manufacturing a semiconductor device according to any one of claims 1 to 6, wherein the shear storage modulus G '(23) of the adhesive layer at 23 ° C is 1.0 × 10 ⁴ to 1.0 × 10 ⁸ Pa. The method for manufacturing a semiconductor device according to any one of claims 1 to 7, wherein the ratio of the thickness of the substrate at 23 ° C to the thickness of the adhesive layer (substrate / adhesive layer) is 0.2. the above. The method for manufacturing a semiconductor device according to any one of claims 1 to 8, wherein the thickness of the substrate at 23 ° C is 10 to 1000 µm, and the thickness of the adhesive layer is 1 to 60 µm. The method for manufacturing a semiconductor device according to any one of claims 1 to 9, wherein the probe viscosity value on the surface of the substrate is less than 50 mN / 5 mmφ. An adhesive sheet is an adhesive sheet used in the method for manufacturing a semiconductor device according to any one of claims 1 to 10, and has an adhesive layer and a non-adhesive base containing an expandable particle in this order. material.