TWI773747B - Manufacturing method of semiconductor device and adhesive sheet - Google Patents

Abstract

The present invention provides a method for manufacturing a semiconductor device and an adhesive sheet used for the manufacturing method. The method for manufacturing a semiconductor device is a method for manufacturing a semiconductor device using an adhesive sheet, the adhesive sheet having: an adhesive layer, and an adhesive layer containing expandable particles and being The non-adhesive base material has the following steps (1) to (4), Step (1): the step of attaching the frame member formed with the opening to the adhesive surface of the adhesive layer; Step (2): the A step of placing a semiconductor wafer on 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 adhesive layer with a sealing material The peripheral portion of the aforementioned semiconductor wafer in the adhesive surface of the above-mentioned semiconductor wafer is hardened, and the step of obtaining a hardened sealing body in which the aforementioned semiconductor wafer is sealed by the hardened sealing material is obtained; The step of peeling the above-mentioned adhesive sheet from the above-mentioned hardened sealing body. The manufacturing method can suppress the positional displacement of the semiconductor chip in the manufacturing step of the fan-out package, and is excellent in productivity, and the resulting semiconductor device has excellent flatness of the rewiring layer formation surface.

Description

Manufacturing method and adhesive sheet of semiconductor device

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

In the past few years, miniaturization, weight reduction, and high functionality of electronic equipment have been advanced, and along with this, miniaturization, thinning, and high density are also required for semiconductor devices mounted in electronic equipment. Semiconductor chips are sometimes mounted in packages close to their size. These packages are also called CSP (Chip Scale Package). Examples of CSPs include WLP (Wafer Level Package), which is processed from wafer size to the final step of packaging, and PLP (Panel Level Package), which is processed from a panel size larger than the wafer size to the final step of packaging. , panel level package) and so on.

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

However, FOWLP and FOPLP are manufactured through the following steps, such as a mounting step of placing a plurality of semiconductor chips on an adhesive sheet for temporary fixing (hereinafter also referred to as a "temporary fixing sheet") to provide a fluid seal The covering step of material coating, the curing step of thermosetting the sealing material, the peeling step of peeling off the temporary fixing sheet from the sealing body, and the rewiring layer forming step of forming the rewiring layer on the exposed surface of the semiconductor wafer side. For the temporary fixing sheet used in the above-mentioned steps, it is required that the positional displacement of the semiconductor wafer does not occur between the above-mentioned coating step and the hardening step (hereinafter also referred to as "sealing step"), and that the sealing material does not enter into the The adhesiveness of the adhesive interface between the semiconductor wafer and the sheet for temporary fixation is required to be such that peelability can be easily removed without residue after the sealing step. That is, the sheet for temporary fixation used in the manufacture of FOWLP and FOPLP is required to have both adhesiveness during use and releasability after use.

For example, Patent Document 1 discloses a method for producing FOWLP for temporarily fixing a base material made of a polyimide film and an adhesive layer made of a silicon-based adhesive provided on the surface of the base material. After the sealing step is performed on the sheet, the sheet is peeled off by bending the sheet for temporary fixation at hand. However, the step of peeling off the temporary fixing sheet by hand or the like is complicated, and from the viewpoint of improving productivity, it is required that the temporary fixing sheet can be peeled off with a smaller external force.

As a sheet for temporary fixation excellent in releasability, for example, Patent Document 2 discloses a heat-peelable adhesive for temporary fixation at the time of cutting of electronic parts provided with a heat-expandable adhesive layer containing heat-expandable microspheres on at least one side of a substrate. flakes. In the manufacture of FOWLP and FOPLP, the use of the heat-peelable adhesive sheet described in Patent Document 2 is also considered. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2015-32646 [Patent Document 2] Japanese Patent No. 3594853

[The problem to be solved by the invention]

However, according to the review by the present inventors, it was found that when the heat-peelable adhesive sheet described in Patent Document 2 is used as a sheet for temporary fixing in the production of FOWLP and FOPLP, it is found that the elastic modulus of the thermally expandable adhesive layer is low, and In the above-mentioned placing step and sealing step, the placed semiconductor chip will sink to the side of the adhesive sheet, and the positional deviation of the semiconductor chip will occur. As a result, after the sealing step, the surface on the semiconductor chip side (hereinafter also referred to as the "rewiring layer forming surface") after removing the adhesive sheet has a level difference between the surface of the semiconductor chip and the surface of the sealing material, so the flatness is poor. , which is the result of a decrease in the positional accuracy of the semiconductor wafer. 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 precision, it is desired to suppress the reduction. In addition, when the adhesive sheet is removed, even if the heat-expandable adhesive layer is expanded by heating, the semiconductor wafer sinks into the adhesive sheet side, so it is considered that it will be difficult to peel off without a certain degree of external force.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide excellent productivity and excellent flatness of the rewiring layer formation surface of the obtained semiconductor device by suppressing the occurrence of positional displacement of the semiconductor chip in the manufacturing process of the fan-out package. A manufacturing method of a semiconductor device and an adhesive sheet used in the manufacturing method. [means to solve the problem]

The inventors of the present invention found that the above-mentioned problems can be solved by using an adhesive sheet having a specific layer including an intumescent particle and a non-adhesive base material in the manufacturing process of the fan-out package. 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 by using an adhesive sheet, the adhesive sheet having: an adhesive layer, and a non-adhesive base material containing intumescent particles, comprising the following steps ( 1) to (4), step (1): the step of attaching the frame member with the opening portion to the adhesive surface of the adhesive layer; step (2): placing the semiconductor wafer on the aforementioned opening of the aforementioned frame member Step (3): Covering the semiconductor chip, the frame member, and the peripheral portion of the semiconductor chip in the adhesive surface of the adhesive layer with a sealing material, The step of hardening the sealing material to obtain a hardened sealing body in which the semiconductor wafer is sealed by the hardening sealing material; Step (4): the step of expanding the intumescent particles and peeling the adhesive sheet from the hardening sealing body . [2] The method of manufacturing a semiconductor device according to the above [1], further comprising the following step (5), step (5): a step of forming a rewiring layer on the peeled cured sealing body of the adhesive sheet. [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 to heat the adhesive sheet to make the thermally expandable particles The step of exfoliating the adhesive sheet from the hardened sealing body by expanding the particles. [4] The method for producing 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 base material satisfies the following requirements (1) to (2), and the requirement (1): the storage modulus of the base material at 100° C. E'(100) is 2.0×10 ⁵ Pa or more; Requirement (2): The storage modulus E′(t) of the base material 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 intumescent particles have an average particle diameter before expansion at 23° C. of 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 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 to the thickness of the adhesive layer at 23° C. (substrate/ 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 the probe tack value of the surface of the substrate is less than 50 mN/5 mmφ. [11] An adhesive sheet for use in the method for manufacturing a semiconductor device according to any one of the above [1] to [10], comprising, in this order: an adhesive layer; It is a non-adhesive substrate. [Inventive effect]

According to the present invention, it is possible to provide a method for manufacturing a semiconductor device which can suppress the occurrence of positional displacement of a semiconductor chip in a manufacturing step of a fan-out package, has excellent productivity, and is excellent in the flatness of the rewiring layer formation surface of the obtained semiconductor device, and the same. The adhesive sheet used in the manufacturing method.

In the present invention, the term "active ingredient" refers to the components contained in the target composition, excluding the diluent solvent. In addition, the mass-average molecular weight (Mw) is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC), specifically, a value measured based on the method described in the examples.

In the present invention, for example, "(meth)acrylic acid" represents both "acrylic acid" and "methacrylic acid", and other similar terms are also the same. In addition, regarding the preferable numerical range (for example, the range of content, etc.), the lower limit value and the upper limit value of the step-by-step description can be independently combined. For example, based on the description of "preferably 10 to 90, more preferably 30 to 60", "10 to 60" may be obtained by combining "preferable lower limit value (10)" and "preferable upper limit value (60)" .

[Method of Manufacturing Semiconductor Device] The method of manufacturing a semiconductor device of the present embodiment is a method of manufacturing a semiconductor device using an adhesive sheet, the adhesive sheet having an adhesive layer, and a non-adhesive base material containing intumescent particles, There are the following steps (1) to (4), Step (1): The step of attaching the frame member with the opening portion to the adhesive surface of the adhesive layer; Step (2): The semiconductor wafer is placed on the aforementioned Step of a part of the adhesive surface of the adhesive layer exposed by the opening of the frame member; Step (3): Covering the semiconductor wafer, the frame member, and the semiconductor in the adhesive surface of the adhesive layer with a sealing material The peripheral part of the wafer, the sealing material is hardened to obtain a hardened sealing body formed by sealing the semiconductor wafer with the hardening sealing material; Step (4): Expand the intumescent particles, and seal the adhesive sheet from the hardening and sealing Body peeling steps. Hereinafter, the adhesive sheet used in the manufacturing method of the semiconductor device of the present embodiment will be explained first, and then the manufacturing steps including steps (1) to (4) will be explained.

<Adhesive sheet> The adhesive sheet of the present 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 intumescent particles. The shape of the adhesive sheet can take all shapes such as sheet-like, tape-like, label-like, etc.

(Configuration of the adhesive sheet) Fig. 1(A) is a cross-sectional view of the adhesive sheet 10 of the present embodiment. As shown in FIG. 1(A), the adhesive sheet 10 of this embodiment has an adhesive layer 12 on a base material 11. In addition, the adhesive sheet of this embodiment may also have a structure of a release material 13 on the adhesive surface 12a of the adhesive layer 12 as shown in FIG. 1(B) . When the adhesive sheet 10a is used in the manufacturing method of the semiconductor device of the present embodiment, the release material 13 is appropriately peeled off and removed.

Hereinafter, the intumescent base material, the pressure-sensitive adhesive layer, and the release material used as needed in the pressure-sensitive adhesive sheet of the present embodiment will be sequentially described.

(Expandable base material) The expandable base material contains expandable particles and is a non-adhesive base material. Generally, the heat-expandable adhesive layer as described in the adhesive sheet described in Patent Document 2 must have a certain thickness because the main component is an adhesive with a low elastic modulus, and the expansive particles are sufficiently contained. Therefore, there is a possibility that the positional deviation of the semiconductor chip occurs between the placing step and the sealing step of the semiconductor chip, the semiconductor chip sinks into the adhesive sheet side, and the formation surface of the wiring layer cannot be flattened. On the other hand, in the adhesive sheet of the present embodiment, since the expandable particles are contained in a non-adhesive resin with a high elastic modulus, the thickness adjustment, the adhesive force, and the viscoelastic modulus of the adhesive layer on which the semiconductor chip is mounted can be improved. Design freedom of control, etc., etc. Thereby, the occurrence of positional displacement of the semiconductor wafer can be suppressed, and at the same time, the semiconductor wafer can be suppressed from sinking into the double-sided adhesive sheet, and a rewiring layer formation surface with excellent flatness can be formed. Furthermore, when the adhesive sheet of this embodiment is used, since the semiconductor wafer is placed on the adhesive surface of the adhesive layer, the intumescent substrate and the rewiring layer forming surface are not in direct contact. Thereby, residues derived from the expansive particles and a part of the greatly deformed adhesive layer are suppressed from adhering to the rewiring layer forming surface, and the uneven shape formed on the thermally expandable adhesive layer is suppressed from being transferred to the rewiring layer forming surface. The smoothness decreases, and a rewiring layer-forming surface excellent in cleanness and smoothness can be obtained.

The thickness of the intumescent base material is preferably from 10 to 1000 μm, more preferably from 20 to 500 μm, still more preferably from 25 to 400 μm, still more preferably from 30 to 300 μm. In addition, in this specification, the thickness of the intumescent base material means the value measured by the method described in the Examples.

The expandable base material of the adhesive sheet is a non-adhesive base material. In the present invention, the judgment of whether it is a non-adhesive substrate is for 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 determined to be "non-adhesive". Adhesive Substrates". Here, the probe viscosity value of the surface of the intumescent substrate used in this embodiment is usually less than 50mN/5mmφ, but preferably less than 30mN/5mmφ, more preferably less than 10mN/5mmφ, still more preferably is less than 5mN/5mmφ. In addition, in this specification, the specific measurement method of the probe viscosity value on the surface of the intumescent substrate is the method described in the examples.

The expandable base material included in the adhesive sheet of the present embodiment contains resin and expandable particles, but an additive for base material may be contained as necessary within a range that does not impair the effects of the present invention. In addition, the intumescent base material may be formed of a resin composition (y) containing a resin and intumescent particles. Next, each component contained in the resin composition (y), which is the material for forming the intumescent base material, will be explained.

<Resin> The resin contained in the resin composition (y) is not particularly limited as long as it is a resin that can make the expandable substrate non-adhesive, and it 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 adhesive resin and the polymerizable compound undergo a polymerization reaction during the process of forming the intumescent base material from the resin composition (y), the The obtained resin becomes a non-adhesive resin, and the intumescent base material containing the resin can be made non-adhesive.

The mass average molecular weight (Mw) of the resin contained in the resin composition (y) is preferably from 1,000 to 1,000,000, more preferably from 1,000 to 700,000, still more preferably from 1,000 to 500,000. Furthermore, when the resin is a copolymer having two or more structural 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 aforementioned resin is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and still more preferably 65 to 90% by mass relative to the total amount of active ingredients (100% by mass) of the resin composition (y). , more preferably 70 to 85% by mass.

As said resin contained in the resin composition (y), it is preferable to contain 1 or more types chosen from acrylic urethane type resin and an olefin type resin. In addition, as the above-mentioned acrylic urethane resin, the following resin (U1) is preferred.・Urethane acrylate resin (U1) obtained by polymerizing urethane prepolymer (UP) and vinyl compound containing (meth)acrylate.

[Acrylic urethane resin (U1)] The urethane prepolymer (UP) serving as the main chain of the acrylic urethane resin (U1) is exemplified by the reaction of a polyol and a polyisocyanate thing. In addition, it is preferable to use a urethane prepolymer (UP) that can further use a chain extension agent to carry out a chain extension reaction.

Examples of polyols used as raw materials for urethane prepolymers (UP) include alkylene polyols, ether polyols, ester polyols, ester polyols, ester/ether polyols Alcohols, carbonate-type polyols, etc. These polyols may be used alone or in combination of two or more. The polyol used in this embodiment is preferably a diol, more preferably an ester-type diol, an alkylene-type diol, and a carbonate-type diol, and still more preferably an ester-type diol and a carbonate-type diol.

Examples of ester-type diols include alkanediols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and the like; ethylene glycol Alkane diols such as alcohol, propylene glycol, diethylene glycol, dipropylene glycol, etc.; one or more selected from such diols and phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid , 4,4-diphenyldicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, chloro bridge acid (Het acid), horse Lactic acid, fumaric acid, itaconic acid, cyclohexane-1,3-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydrophthalic acid A polycondensate of one or more selected from dicarboxylic acids such as hydrogen terephthalic acid and methylhexahydrophthalic acid, and anhydrides thereof. Specifically, polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyhexamethylene isophthalate diol, polyhexamethylene adipate diol, Neopentyl adipate diol, poly(ethylene propylene adipate) diol, poly(ethylene butyl adipate) diol, poly(butylene adipate) hexamethylene diol, poly(ethylene adipate) Diethylene adipate diol, poly(polytetramethylene ether) adipate diol, poly(3-methylpentylene adipate) diol, poly(ethylene azelaate) Ester diol, polyethylene sebacate diol, polybutylene sebacate diol, polybutylene sebacate diol and polyneopentyl terephthalate diol, etc.

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

Examples of carbonate-type diols include, for example, 1,4-tetramethylene carbonate diol, 1,5-pentamethylene carbonate diol, 1,6-hexamethylene carbonate diol, and 1,6-hexamethylene carbonate diol. ,2-Propylene glycol, 1,3-Propylene carbonate, 2,2-dimethylpropylene carbonate, 1,7-heptamethylene carbonate, 1,8-octamethylene carbonate diol, 1,4-cyclohexyl carbonate diol, etc.

As a polyvalent isocyanate which becomes a raw material of a urethane prepolymer (UP), aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, etc. are mentioned, for example. These polyvalent isocyanates may be used alone or in combination of two or more. In addition, these polyvalent isocyanates may also be trimethylolpropane addition-type modifiers, biuret-type modifiers that react with water, and isocyanurate-type modifiers containing isocyanurate rings.

Among these, the polyvalent isocyanate used in the present embodiment is preferably a diisocyanate, more preferably selected from the group consisting of 4,4'-diphenylmethane diisocyanate (MDI), 2,4-toluene diisocyanate (2,4 -TDI), 2,6-toluene diisocyanate (2,6-TDI), hexamethylene diisocyanate (HMDI) and 1 or more types of alicyclic diisocyanate.

Examples of alicyclic diisocyanates include, for example, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), 1,3-cyclopentane diisocyanate, 1 ,3-cyclohexanediisocyanate, 1,4-cyclohexanediisocyanate, methyl-2,4-cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, etc., preferably isocyanurate Phorone diisocyanate (IPDI).

In the present embodiment, as a reaction product of a urethane prepolymer (UP)-based diol and a diisocyanate serving as the main chain of the acrylic urethane-based resin (U1), it is preferable that both ends have Linear urethane prepolymer with ethylenically unsaturated groups. As a method of introducing ethylenically unsaturated groups into both ends of the linear urethane prepolymer, the ends of the linear urethane prepolymer obtained by reacting a diol with a diisocyanate compound are exemplified. A method for the reaction of the NCO group with (meth) hydroxyalkyl 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, etc.

At least (meth)acrylate is contained as a vinyl compound which becomes a side chain of acrylate urethane resin (U1). As the (meth)acrylate, at least one selected from the group consisting of alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate is preferred, and alkyl (meth)acrylate and (meth)acrylic acid are more preferably used in combination Hydroxy alkyl esters.

When an alkyl (meth)acrylate and a hydroxyalkyl (meth)acrylate are used in combination, the mixing ratio of the hydroxyalkyl (meth)acrylate is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of the alkyl (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, still more preferably 1.5 to 10 parts by mass.

1-24 are preferable, 1-12 are more preferable, 1-8 are still more preferable, and 1-3 are still more preferable.

In addition, as the hydroxyalkyl (meth)acrylate, the same as the hydroxyalkyl (meth)acrylate used for introducing ethylenically unsaturated groups into both ends of the above-mentioned linear urethane prepolymer. .

Examples of vinyl compounds other than alkyl (meth)acrylates include aromatic hydrocarbon vinyl compounds such as styrene, α-methylstyrene, vinyltoluene, and the like; methyl vinyl ether, ethyl vinyl ether, and the like. vinyl ethers; vinyl acetate, vinyl propionate, (meth)acrylonitrile, N-vinylpyrrolidone, (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 from 40 to 100 mass %, more preferably from 65 to 100 mass %, more preferably from 40 to 100 mass % with respect to the total amount (100 mass %) of the vinyl compound. It is 80-100 mass %, More preferably, it is 90-100 mass %.

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

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

In the acrylic urethane resin (U1) used in the present embodiment, the difference between the structural unit (u11) derived from the urethane prepolymer (UP) and the structural 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, still more preferably 30/70 to 60/40 , and more preferably 35/65 to 55/45.

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

Examples of specific olefin-based resins include, for example, ultra-low density polyethylene (VLDPE, density: 880 kg/m ³ or more and less than 910 kg/m ³ ), low density polyethylene (LDPE, density: 910 kg/m ³ or more and less than 910 kg/m 3 ). 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), linear low Polyethylene resin such as density polyethylene; polypropylene resin (PP); polybutene resin (PB); ethylene-propylene copolymer; olefin-based elastomer (TPO); poly(4-methyl-1-pentene) (PMP); ethylene-vinyl acetate copolymer (EVA); ethylene-vinyl alcohol copolymer (EVOH); ethylene-propylene-(5-ethylene-2-norbornene) and other olefin-based terpolymers ;Wait.

In the present embodiment, the olefin-based resin may be a modified olefin-based resin further modified by one or more kinds selected from acid modification, hydroxyl modification, and acrylic modification.

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

Examples of the acrylic-modified olefin-based resin in which the acrylic-modified olefin-based resin is modified by acrylic acid include a modified polymer of alkyl (meth)acrylate, which is graft-polymerized to the main chain of the above-mentioned non-modified olefin-based resin as a side chain. . The number of carbon atoms of the alkyl group contained in the above-mentioned alkyl (meth)acrylate is preferably from 1 to 20, more preferably from 1 to 16, still more preferably from 1 to 12. Examples of the above-mentioned alkyl (meth)acrylate are the same as the compounds that can be selected as the monomer (a1') to be described later.

Examples of the hydroxyl-modified olefin-based resin in which the hydroxyl-modified olefin-based resin is modified with a hydroxyl group include a modified polymer obtained by graft-polymerizing a hydroxyl-containing compound to the above-mentioned non-modified olefin-based resin of the main chain. Examples of the above-mentioned hydroxyl-containing compound include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxyl (meth)acrylate. Hydroxyalkyl (meth)acrylates such as butyl ester, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, etc.; unsaturated alcohols such as vinyl alcohol and allyl alcohol, etc.

[Resins other than acrylic urethane resins and olefin resins] In the present embodiment, the resin composition (y) may contain acrylic urethane resins within a range that does not impair the effects of the present invention Resins other than resins and olefin-based resins. Examples of these resins include 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 copolymers; cellulose triacetate; polycarbonate; polyurethanes not equivalent to acrylic urethane resins ; Polyetherimide; Polyetheretherketone; Polyetherimide; Polyphenylene sulfide; Polyimide resins such as polyetherimide, polyimide, etc.; . The content ratio of resins other than the acrylic urethane-based resin and the olefin-based resin is preferably less than 30 parts by mass, more preferably less than 100 parts by mass relative to 100 parts by mass of the total resin contained in the resin composition (y). 20 parts by mass, more preferably less than 10 parts by mass, more preferably less than 5 parts by mass, and still better less than 1 part by mass.

<Expandable particles> The expandable particles are not particularly limited as long as they can expand by themselves by external stimuli to form irregularities in the adhesive layer and reduce the adhesive force with the adhesive. Examples of the expandable particles include thermally expandable particles expanded by heating, energy linear expandable particles expanded by irradiation with energy rays, and the like, but thermally expandable particles are preferred from the viewpoint of wide usability and handleability. .

The thermally expandable particles are preferably adjusted to have an expansion start temperature (t) of 120 to 250°C. In addition, in this specification, the expansion start temperature (t) of thermally expandable particles means a value measured by the following method. [Measurement method for the expansion start temperature (t) of heat-expandable particles] An aluminum pan with a diameter of 6.0 mm (inner diameter of 5.65 mm) and a depth of 4.8 mm was prepared, and 0.5 mg of the heat-expandable particles to be measured were added, and the lid was removed from the top. Hold the sample of aluminum cover (diameter 5.6mm, thickness 0.1mm). Using a dynamic viscoelasticity measuring device, the height of the sample was measured in a state where a force of 0.01 N was applied to the sample from the top of the aluminum cover by a presser. Next, in a state where a force of 0.01 N is applied by the pressurizer, the temperature is increased from 20°C to 300°C at a heating rate of 10°C/min, and the displacement of the pressurizer in the vertical direction is measured, and the displacement in the positive direction is started. The temperature is taken as the expansion start temperature (t).

The heat-expandable particles are preferably a microencapsulated foaming agent composed of a shell made of a thermoplastic resin and an encapsulated component contained in the shell and vaporized when heated to a specific temperature. As the thermoplastic resin constituting the shell of the microencapsulated foaming agent, for example, vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride are exemplified. , Poly dust, etc.

Examples of the components contained 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, cyclodecane Tridecane, 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, Isononadecane, 2 ,6,10,14-Tetramethylheptadecane, cyclotridecane, heptylcyclohexane, n-octylcyclohexane, cyclopentadecane, nonylcyclohexane, decylcyclohexane, ten Pentaalkylcyclohexane, hexadecylcyclohexane, heptadecylcyclohexane, octadecylcyclohexane, etc. These in-package ingredients can be used alone or in combination of two or more. The expansion start temperature (t) of the heat-expandable particles can be adjusted by appropriately selecting the type of the contained components.

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

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

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

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

<Additives for substrates> The resin composition (y) used in the present embodiment may contain additives for substrates contained in the substrates of general adhesive sheets within the range that does not impair the effects of the present invention. Examples of such additives for substrates include ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, slip agents, antiblocking agents, colorants, and the like. In addition, each of these base material additives may be used alone, or two or more of them may be used in combination. When these additives for substrates are contained, the content of each additive for substrates is preferably 0.0001 to 20 parts by mass, more preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the aforementioned resin in the resin composition (y). .

<Solvent-free resin composition (y1)> One aspect of the resin composition (y) used in the present embodiment is, for example, an oligomer having an ethylenically unsaturated group having a mass average molecular weight (Mw) of 50,000 or less. A solvent-free resin composition (y1) in which a substance and an energy ray polymerizable monomer and the above-mentioned expandable particles are not prepared with a solvent. The solvent-free resin composition (y1) does not contain a solvent, but the energy ray polymerizable monomer contributes to improving the plasticity of the aforementioned oligomer. An intumescent substrate can be obtained by irradiating energy rays to the coating film formed from the solvent-free resin composition (y1).

The type, shape, and compounding amount (content) of the expandable particles to be prepared in the solvent-free resin composition (y1) are as described above.

The mass average molecular weight (Mw) of the aforementioned oligomer contained in the solvent-free resin composition (y1) is 50,000 or less, preferably 1,000 to 50,000, more preferably 2,000 to 40,000, still more preferably 3,000 to 35,000, More preferably, it is 4,000 to 30,000.

In addition, the oligomer may be any one 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), and preferably the above-mentioned amino group Formate prepolymer (UP). In addition, as the oligomer, a modified olefin-based resin having an ethylenically unsaturated group or the like can also be used.

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

Examples of the energy ray polymerizable monomer include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyl (meth)acrylate. Alicyclic polymerizable compounds such as base ester, cyclohexyl (meth)acrylate, adamantyl (meth)acrylate, tricyclodecyl acrylate, etc.; phenylhydroxypropyl acrylate, benzyl acrylate, phenol ethylene oxide Aromatic polymerizable compounds such as alkane-modified acrylates; heterocyclic polymerization of tetrahydrofurfuryl (meth)acrylate, morpholine acrylate, N-vinylpyrrolidone, N-vinylcaprolactam, etc. sexual compounds, etc. These energy ray polymerizable monomers may be used alone or in combination of two or more.

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

In the present embodiment, it is preferable to further prepare a photopolymerization initiator in the solvent-free resin composition (y1). By containing a photopolymerization initiator, the curing reaction can be fully carried out even if it is irradiated with a relatively low-energy energy ray.

Examples of the photopolymerization initiator include, for example, 1-hydroxy-cyclohexyl-phenyl ketone, phenylin, phenylin methyl ether, phenylin ethyl ether, phenylin propyl ether, phenylin phenyl sulfide, tetramethylene Kitthiuram monosulfide, azobisisobutyronitrile, biphenyl aldehyde, diacetyl aldehyde, 8-chloroanthraquinone, etc. These photopolymerization initiators may be used alone or in combination of two or more.

The compounding amount of the photopolymerization initiator is preferably 0.01 to 5 parts by mass, more preferably 0.01 to 4 parts by mass, and more Preferably, it is 0.02-3 mass parts.

<Storage modulus of substrate> The storage modulus E' (23) at 23°C of the swellable substrate of the adhesive sheet of the present embodiment is preferably 1.0×10 ⁶ Pa or more, more preferably 5.0× 10 ⁶ to 5.0×10 ¹² Pa, still more preferably 1.0×10 ⁷ to 1.0×10 ¹² Pa, still more preferably 5.0×10 ⁷ to 1.0×10 ¹¹ Pa, still more preferably 1.0×10 ⁸ to 1.0 ×10 ¹⁰ Pa. By using the expansive substrate having the storage modulus E' (23) within the above-mentioned range, the positional displacement of the semiconductor chip can be prevented, and the sinking of the semiconductor chip toward the adhesive layer can also be prevented. For example, the semiconductor chip can be mounted in such a way that its circuit surface is covered by the adhesive surface of the adhesive layer. Conventional devices such as flip-chip bonders and wafer bonders are sometimes used for mounting the semiconductor chips. In the above procedure, when the semiconductor chip is placed on the adhesive layer of the adhesive sheet using a flip-chip bonder or a wafer bonder, there is an excess of the semiconductor chip due to the application of a pressing force that presses the semiconductor chip in the thickness direction of the adhesive sheet. There is a risk of sinking into the thickness direction side of the adhesive layer. In addition, when a flip chip bonder or a wafer bonder is used to place the semiconductor chip on the adhesive sheet, since the semiconductor chip is also applied with a force to move in the horizontal direction of the adhesive sheet, the semiconductor chip is also at the level of the adhesive layer. The risk of positional deviation of the direction. However, these problems can also be solved by using an intumescent substrate that satisfies the above-mentioned storage modulus E' (23). In addition, in this specification, the storage modulus E' of the intumescent base material in a specific temperature means the value measured by the method as described in an Example.

Furthermore, it is preferable that the expandable base material of 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 intumescent base material at 100°C is 2.0×10 ⁵ Pa or more. By having an intumescent base material that satisfies the requirement (1), even in the temperature environment of the sealing step in the production process of FOWLP and FOPLP, the flow of inflatable particles can be suppressed to a good degree, so it is provided on the intumescent base material. The adhesive surface of the above adhesive layer is also difficult to deform. As a result, the positional displacement of the semiconductor chip can be prevented, and the sinking of the semiconductor chip into the adhesive layer can also be prevented.

From the above viewpoints, the storage modulus E'(100) of the intumescent base material is preferably 4.0×10 ⁵ Pa or more, more preferably 6.0×10 ⁵ Pa or more, still more preferably 8.0×10 ⁵ Pa or more, and furthermore More preferably, it is 1.0×10 ⁶ Pa or more. In addition, in the sealing step, from the viewpoint of effectively suppressing displacement of the semiconductor wafer, the storage modulus E'(100) of the intumescent substrate is preferably 1.0×10 ¹² Pa or more, more preferably 1.0×10 ¹¹ Pa or less, still more preferably 1.0×10 ¹⁰ Pa or less, still more preferably 1.0×10 ⁹ Pa or less.

In addition, when the expandable base material of 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 base material at the expansion start temperature (t) of the thermally expandable particles is 1.0×10 ⁷ Pa or less. By having the expandable base material that satisfies the requirement (2), at the temperature at which the heat-expandable particles are expanded, the expandable base material is easily deformed following the volume expansion of the heat-expandable particles, and concavities and convexities are easily formed on the adhesive surface of the adhesive layer. Thereby, it can be peeled off from the object by a little external force.

From the above viewpoints, the storage modulus E'(t) of the intumescent substrate is preferably 9.0×10 ⁶ Pa or less, more preferably 8.0×10 ⁶ Pa or less, still more preferably 6.0×10 ⁶ Pa or less, and furthermore More preferably, it is 4.0×10 ⁶ Pa or less. In addition, the storage modulus E'(t) of the intumescent base material is based on the viewpoint of improving the shape retention of the unevenness formed on the adhesive surface of the adhesive layer, and further improving the releasability based on the flow of the thermally expansible particles that suppress the expansion, It is preferably at least 1.0×10 ³ Pa, more preferably at least 1.0×10 ⁴ Pa, and still more preferably at least 1.0×10 ⁵ Pa.

(Adhesive layer) The adhesive layer of the adhesive sheet of the present embodiment may contain an adhesive resin as long as it is an adhesive layer containing a crosslinking agent, an adhesive imparting agent, a polymerizable compound, a polymerization initiator, etc. as required. Dosage additives. Furthermore, the adhesive layer is preferably a non-expandable adhesive layer from the viewpoint of preventing the mounted semiconductor wafer from sinking into the adhesive layer due to heating in the sealing step.

In the adhesive sheet of the present embodiment, the adhesive force of the adhesive surface of the adhesive layer before the expansion of the expandable particles at 23°C is preferably 0.1 to 10.0 N/25mm, more preferably 0.2 to 8.0 N/25mm, and still more Preferably it is 0.4-6.0N/25mm, More preferably, it is 0.5-4.0 N/25mm. If the adhesive force is 0.1N/25mm or more, it can be sufficiently fixed to the extent that the positional displacement of the semiconductor wafer can be prevented during the sealing step. On the other hand, if the adhesive force is 10.0N/25mm or less, when peeling from the adhesive, it can be easily peeled off with a little external force. In addition, the above-mentioned adhesive force means the value measured by the method described in the Example.

In the adhesive sheet of the present 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, more preferably 5.0×10 ⁴ ∼5.0×10 ⁷ Pa, 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, it is preferable that the shear storage modulus G' (23) of the adhesive layer to which the semiconductor chip is bonded is within the above range, and the semiconductor chip from the expandable substrate is preferably 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 positional displacement of the semiconductor wafer can be prevented, and the sinking of the semiconductor wafer toward the adhesive layer can also be prevented. On the other hand, if the shear storage modulus G'(23) of the adhesive layer is 1.0×10 ⁸ Pa or less, the surface of the adhesive layer is likely to form irregularities due to the expansion of the intumescent particles in the intumescent substrate. , as a result, it can be easily peeled off with a little force. In addition, in this specification, the shear storage modulus G' (23) of an adhesive bond layer means the value measured by the method as described in an Example.

The thickness of the adhesive layer of the adhesive sheet of the present embodiment is based on the viewpoint of exhibiting excellent adhesive force and the viewpoint of easily forming concavities and convexities on the surface of the adhesive layer formed by the expansion of the intumescent particles in the intumescent substrate , preferably from 1 to 60 μm, more preferably from 2 to 50 μm, still more preferably from 3 to 40 μm, still more preferably from 5 to 30 μm.

In the adhesive sheet of this embodiment, the ratio of the thickness of the intumescent substrate to the thickness of the adhesive layer at 23°C (intumescent substrate/adhesive layer) is based on making the rewiring layer formation surface flat and preventing the semiconductor wafer from being damaged. From the viewpoint of positional displacement, it is preferably at least 0.2, more preferably at least 0.5, still more preferably at least 1.0, still more preferably at least 5.0, and from the viewpoint of being an adhesive sheet that can be easily peeled off with a little force at the time of peeling , preferably at most 1000, more preferably at most 200, still more preferably at most 60, still more preferably at most 30. The thickness of the adhesive layer means the 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 explained.

<Adhesive resin> As the adhesive resin used in the present embodiment, it is preferable that the resin alone has adhesiveness, and the mass average molecular weight (Mw) is a polymer of 10,000 or more. The mass average molecular weight (Mw) of the adhesive resin used in the present embodiment is preferably from 10,000 to 2,000,000, more preferably from 20,000 to 1,500,000, still more preferably from 30,000 to 100,000 from the viewpoint of improving the adhesive force. Ten thousand.

Examples of the adhesive resin include rubber-based resins such as acrylic resins, urethane-based resins, and polyisobutylene-based resins, polyester-based resins, olefin-based resins, silicone-based resins, and polyvinyl ether-based resins. These adhesive resins can be used alone or in combination of two or more. In addition, when these adhesive resins are copolymers having two or more structural units, the form of the copolymers is not particularly limited, and may be any of block copolymers, random copolymers, and graft copolymers 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 the side chain of the above-mentioned adhesive resin. Examples of the polymerizable functional group include a (meth)acryloyl group, a vinyl group, and the like. Further, examples of the energy rays include ultraviolet rays, electron beams, and the like, and ultraviolet rays are preferred.

The content of the adhesive resin is preferably from 30 to 99.99% by mass, more preferably from 40 to 99.95% by mass, more preferably from 50 to 99.90% by mass relative to the total amount of active ingredients (100% by mass) of the adhesive composition, More preferably, it is 55 to 99.80 mass %, and still more preferably, it is 60 to 99.50 mass %. In addition, in the following description of this specification, "the content of each component relative 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 the present embodiment, from the viewpoint of exhibiting excellent adhesive force, and from the viewpoint that the expansion of the expandable particles in the expandable substrate by heat treatment makes it easier to form unevenness on the surface of the formed adhesive layer, the adhesive resin is relatively It is good to include acrylic resin. The content ratio 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 (100% by mass) of the adhesive resin contained in the adhesive composition. More preferably, it is 70-100 mass %, More preferably, it is 85-100 mass %.

[Acrylic Resin] In the present embodiment, as an acrylic resin that can be used as an adhesive resin, for example, a polymer containing a structural unit derived from an alkyl (meth)acrylate having a linear or branched alkyl group is exemplified. substances, including polymers derived from structural units of (meth)acrylates having a cyclic structure, and the like.

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

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

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

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

The content of the structural unit (a1) is preferably from 50 to 99.9 mass %, more preferably from 60 to 99.0 mass %, more preferably from 70 to all structural units (100 mass %) of the acrylic copolymer (A1). to 97.0 mass %, more preferably 80 to 95.0 mass %.

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

Examples of the hydroxyl group-containing monomer are the same as the above-mentioned hydroxyl group-containing compounds.

Examples of carboxyl-containing monomers 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-(acryloyloxy)ethyl salicylate, 2-carboxyethyl (meth)acrylate, etc.

The content of the structural unit (a2) is preferably from 0.1 to 40 mass %, more preferably from 0.5 to 35 mass %, more preferably from 1.0 to all structural units (100 mass %) of the acrylic copolymer (A1). to 30% by mass, more preferably 3.0 to 25% by mass.

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

Examples of the monomer (a3') include olefins such as ethylene, propylene, isobutylene, etc.; halogenated olefins such as vinyl chloride and vinylidene chloride; and dienes such as butadiene, isoprene, and chloroprene. Monomers: Cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate , (meth)acrylates with cyclic structure such as dicyclopentenyloxyethyl (meth)acrylate, imide (meth)acrylate, etc.; styrene, α-methylstyrene, vinyl Toluene, vinyl formate, vinyl acetate, acrylonitrile, (meth)acrylamide, (meth)acrylonitrile, (meth)acrylomorpholine, N-vinylpyrrolidone, etc.

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

<Crosslinking agent> In the present embodiment, when the adhesive composition contains the functional group-containing adhesive resin of the above-mentioned acrylic copolymer (A1), it is preferable to further contain a crosslinking agent. The cross-linking agent reacts with the adhesive resin with functional group, and the functional group is used as the starting point of cross-linking, so that the adhesive resin is cross-linked 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 may be used alone or in combination of two or more. Among these cross-linking agents, isocyanate-based cross-linking agents are preferred from the viewpoints of improving cohesion, improving adhesion, and ease of acquisition.

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

<Adhesion-imparting agent> In the present embodiment, the adhesive composition preferably further contains an adhesion-imparting agent from the viewpoint of further improving the adhesive force. In this specification, the so-called "adhesion imparting agent" refers to a component that assists in improving the adhesive force of the above-mentioned adhesive resin, and refers to an oligomer with a mass average molecular weight (Mw) of less than 10,000, which is different from the above-mentioned adhesive resin. . The mass average molecular weight (Mw) of the adhesion imparting agent is preferably from 400 to 10,000, more preferably from 500 to 8,000, still more preferably from 800 to 5,000.

Examples of the adhesion imparting agent include C5 of rosin-based resin, terpene-based resin, styrene-based resin, pentene, isoprene, piperine, 1,3-pentadiene, etc. generated by thermal decomposition of naphtha. C9-based petroleum resins obtained by copolymerization of fractions, C9-based petroleum resins obtained by copolymerization of C9-fractions such as indene generated by thermal decomposition of petroleum naphtha, vinyltoluene, etc., and hydrogenated resins obtained by hydrogenating them.

The softening point of the adhesion imparting agent is preferably from 60 to 170°C, more preferably from 65 to 160°C, still more preferably from 70 to 150°C. In addition, in this specification, the "softening point" of the adhesion-imparting agent refers to the value measured according to JIS K 2531. Adhesion imparting agents can be used alone or in combination of two or more with different softening points and structures. Furthermore, when two or more kinds of plural adhesion-imparting agents are used, the weighted average of the softening points of these plural adhesion-imparting agents preferably falls within the above-mentioned 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 of active ingredients (100% by mass) in the adhesive composition, More preferably, it is 0.5 to 45 mass %, and still more preferably, it is 1.0 to 40 mass %.

<Photopolymerization initiator> 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 with energy rays of relatively low energy. The hardening reaction can adjust the adhesive force to the desired range. In addition, as the photopolymerization initiator, the same ones formulated in the above-mentioned solvent-free resin composition (y1) are exemplified.

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 relative to 100 parts by mass of the energy ray-curable adhesive resin.

<Additives for Adhesives> In the present embodiment, the adhesive composition of the material for forming the adhesive layer may contain, in addition to the above-mentioned additives, adhesives used in general adhesives within the scope of not impairing the effects of the present invention. with additives. Examples of additives for the adhesive include antioxidants, softeners (plasticizers), rust inhibitors, pigments, dyes, retarders, reaction accelerators (catalysts), and ultraviolet absorbers. In addition, each of these additives for adhesives may be used alone, or two or more of them may be used in combination.

When these additives for adhesives are contained, the content of each additive for adhesives is preferably 0.0001-20 parts by mass, more preferably 0.001-10 parts by mass with respect to 100 parts by mass of the adhesive resin.

The adhesive composition of the material for forming the adhesive layer may contain expandable particles within a range that does not impair the effects of the present invention. However, as described above, the adhesive layer included in the adhesive sheet of the present embodiment is preferably a non-expandable adhesive layer. Therefore, the content of the expandable particles in the adhesive composition of the material for forming the adhesive layer is preferably reduced as much as possible. The content of the expandable particles is preferably less than 5% by mass, more preferably less than 1% by mass, still more preferably less than 0.1% by mass, relative to the total amount of active ingredients (100% by mass) of the adhesive composition, More preferably, it is less than 0.01 mass %, and particularly preferably, it is less than 0.001 mass %.

(Release material) As shown in the adhesive sheet 10a of FIG. 1(B), the adhesive sheet of this embodiment may further have a release material on the adhesive surface of the adhesive layer. As a release material, a release sheet with a release treatment on both sides or a release sheet with a release treatment on one side is used, for example, a release agent is applied to the base material for the release material.

As the base material for the release material, there are exemplified papers such as fine paper, cellophane, kraft paper, etc.; polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate Polyester resin films of resins, etc., plastic films of olefin resin films of polypropylene resins, polyethylene resins, etc.; etc.

Examples of the release agent include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, butadiene-based resins, etc., 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 from 10 to 200 μm, more preferably from 25 to 170 μm, still more preferably from 35 to 80 μm.

[Manufacturing method of the adhesive sheet] The manufacturing method of the adhesive sheet of the present embodiment is not particularly limited, and the manufacturing method (a) having the following steps (1a) and (2a) is exemplified.・Step (1a): On the peeling treatment surface of the release material, apply the resin composition (y) of the forming material of the intumescent base material to form a coating film, and after drying or UV curing the coating film, the intumescent base material is formed steps.・Step (2a): On the surface of the formed intumescent substrate, the adhesive composition of the material for forming the adhesive layer is applied to form a coating film, and the coating film is dried to form the adhesive layer.

Moreover, as another manufacturing method of the adhesive sheet of this embodiment, the manufacturing method (b) which has the following steps (1b)-(3b) is exemplified.・Step (1b): On the peeling-treated surface of the release material, apply the resin composition (y) of the forming material of the intumescent base material to form a coating film, and after drying or UV curing the coating film, the intumescent base material is formed steps.・Step (2b): The step of coating the adhesive composition of the material for forming the adhesive layer on the peeling treatment surface of the release material to form a coating film, and drying the coating film to form the adhesive layer.・Step (3b): The step of attaching the surface of the intumescent substrate formed in the step (1b) to the surface of the adhesive layer formed in the step (2b).

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

In addition, drying or UV irradiation of the intumescent substrate formed from the coating film in the step (1a) of the production method (a) and the step (1b) of the production method (b) is preferably carried out by appropriately selecting conditions that do not swell the intumescent particles. . For example, when the resin composition (y) containing heat-expandable particles is dried to form an expandable base material, the drying temperature is preferably lower than the expansion start temperature (t) of the heat-expandable particles.

<Each step of manufacturing the semiconductor device of the present embodiment> Next, each step of the method of manufacturing the semiconductor device of the present embodiment will be described. The method of manufacturing a semiconductor device of the present embodiment is a method of 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 formed to the adhesive surface of the adhesive layer; Step (2): Mounting a semiconductor wafer on the adhesive layer exposed in the opening of the frame member Step (3): Cover the peripheral portion of the semiconductor wafer, the frame member, and the adhesive surface of the adhesive layer with a sealing material, and harden the sealing material to obtain The step of hardening the sealing body in which the semiconductor wafer is sealed by the hardening sealing material; Step (4): the step of expanding the intumescent particles and peeling the adhesive sheet from the hardening sealing body. Hereinafter, each step of the manufacturing method of the semiconductor device of the present embodiment will be described with reference to the drawings.

(Step (1)) FIG. 2(A) shows a cross-sectional view illustrating the step (1) of laminating the frame member 20 having the opening 21 on the adhesive surface 12a of the adhesive layer 12 of the adhesive sheet 10. In addition, when the adhesive sheet 10 has the peeling material 13, the peeling material 13 is peeled off 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. As the material of the frame member 20, for example, metals such as copper, stainless steel, 42 alloy; polyimide resin, polyacetal resin, polyamide resin, polycarbonate resin, modified polyphenylene ether resin, polyparaphenylene Resins called engineering plastics such as butylene diformate resins; composite materials such as glass epoxy resins, etc. The thickness t _FR of the frame member 20 is, for example, 100 μm to 3 mm, preferably 100 μm to 1 mm, more preferably 100 to 500 μm. When the thickness t _FR of the frame member 20 is 100 μm or more, the warpage 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, the productivity of the manufacturing process of the semiconductor device can be prevented from being lowered. The opening portion 21 is a hole penetrating the front and back surfaces of the frame member 20 . The shape of the opening portion 21 is not particularly limited as long as the semiconductor wafer CP can be accommodated in the frame. The hole depth of the opening portion 21 is not particularly limited as long as the semiconductor wafer CP can be accommodated. In addition, in the present embodiment, the frame member 20 having a plurality of openings 21 is used, but when the object of the present invention is achieved, a frame member having one opening may be used. The frame member 20 is preferably one that can mount the plurality of semiconductor wafers CP on the adhesive surface 12a in a matrix-like state in which a plurality of semiconductor wafers CP are arranged in a plurality of rows and a plurality of rows with a certain interval therebetween.

(Step (2)) FIG. 2(B) shows a cross-sectional view illustrating the step (2) of placing the semiconductor chip CP on a portion of the adhesive surface 12a of the adhesive layer 12 exposed at the opening 21 of the frame member 20. As the semiconductor chip CP, a conventionally known one can be used. In the semiconductor chip CP, an integrated circuit composed of circuit elements such as transistors, resistors, and capacitors is formed on the circuit surface W1 thereof. The semiconductor chip CP is mounted, for example, in such a manner that its circuit surface W1 is covered by the adhesive surface 12a. The mounting of the semiconductor chip CP may use conventional devices such as a flip chip bonder and a die bonder. The arrangement layout and the number of arrangements of the semiconductor chip CP may be appropriately determined according to the intended package form, the number of production, and the like. Herein, the manufacturing method of the semiconductor device of the present embodiment covers the semiconductor chip CP such as FOWLP, FOPLP, etc. with a sealing material in an area larger than the size of the chip, and can be preferably applied not only to the circuit surface of the semiconductor chip CP W1, also forms an encapsulation of the redistribution layer on the surface area of the sealing material. Therefore, the semiconductor chip CP is placed on a portion of the adhesive surface 12a of the adhesive layer 12 exposed from the opening 21 of the frame member 20, and preferably the semiconductor chip CP is spaced from the frame member 20 surrounding the semiconductor chip CP. Place at regular intervals. The interval between the semiconductor chip CP and the frame member 20 may be appropriately determined according to the intended packaging form and the like. The semiconductor chip CP is placed on a portion of the adhesive surface 12a of the adhesive layer 12 exposed from the opening 21 of the frame member 20 to form the peripheral portion 30 of the semiconductor chip CP in the adhesive surface 12a of the adhesive layer 12. In FIG. 2(B) , the peripheral portion 30 of the semiconductor wafer CP corresponds to the adhesive surface 12a of the adhesive layer 12 in the gap 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 in the adhesive surface 12a of the semiconductor wafer CP, the frame member 20, and the adhesive layer 12 is shown with the sealing material 40. A cross-sectional view of step (3) of obtaining a hardened sealing body 50 in which the semiconductor wafer CP is sealed by the hardened sealing material 41 by coating and hardening the sealing material 40 . 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 on the adhesive surface 12a of the adhesive layer 12 with the sealing material 40 may be referred to as a "coating step", and may be referred to as a "coating step". The step of hardening the sealing material 40 to obtain the hardened sealing body 50 in which the semiconductor wafer CP is sealed by the hardening sealing material 41 is referred to as a "hardening step".

As shown in FIG. 2(C) , in the coating step, the semiconductor chip CP, the frame member 20, and the peripheral portion 30 of the semiconductor chip CP in the adhesive surface 12a of the adhesive layer 12 are coated with the sealing material 40. The sealing material 40 covers the entire exposed surfaces 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 the function of protecting the semiconductor chip CP and its accompanying elements from the external environment. The sealing material 40 is not particularly limited, and any one can be appropriately selected and used from conventional users as a semiconductor sealing material. From the viewpoints of mechanical strength, heat resistance, insulating properties, etc., the sealing material 40 is curable, such as a thermosetting resin composition, an energy ray curable resin composition, and the like. Hereinafter, in this embodiment, the case where the sealing material 40 is a thermosetting resin composition will be described.

As the thermosetting resin contained in the thermosetting resin composition of the sealing material 40, for example, epoxy resin, phenol resin, cyanate resin, etc. are exemplified, 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 phenol resin-based curing agent, a curing agent such as an amine-based curing agent, a curing accelerator, an inorganic filler such as silicon oxide, Additives for elastomers, etc. The sealing material 40 can be solid or liquid at room temperature. Moreover, the form of the sealing material 40 that is solid at room temperature is not particularly limited, for example, it can be in the form of granules, flakes, and the like.

As the method of covering the semiconductor chip CP, its peripheral portion 30 and the frame member 20 with the sealing material 40, any method can be appropriately selected from the conventional methods applied to the semiconductor packaging step and used. Press method, vacuum lamination method, spin coating method, die nozzle coating method, transfer injection molding method, compression molding method, etc. In these methods, generally, in order to improve the filling property of the sealing material 40, the sealing material 40 is heated to impart fluidity during coating.

As shown in FIG. 2(D) , after the coating step is performed, the sealing material 40 is cured to obtain a cured sealing body 50 in which the semiconductor wafer CP is sealed with the cured sealing material 41 . Here, as described above, the adhesive sheet 10 used in this embodiment contains expansive particles that are expanded by heat, energy rays, etc., and in step (4) described later, the expansive particles are expanded to cause adhesion The adhesion between the surface 12 a and the hardened sealing body 50 is reduced, and the adhesive sheet 10 is peeled off from the hardened sealing body 50 . Therefore, in the coating step and the hardening step, it is preferable to appropriately select the conditions that do not expand the expandable particles, and coat the sealing material 40 and harden it. For example, when the expandable particles contained in the adhesive sheet 10 are heat-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 heat-expandable particles The heating conditions of the thickness increase rate of 10% or less, more preferably the heating conditions of the above-mentioned increase rate of 5% or less, and more preferably the heating conditions of the above-mentioned increase rate of 0% (that is, the heating conditions that do not expand the heat-expandable particles). condition). In addition, 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") to measure the adhesion 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 Also, the coating step and the hardening step can be performed individually, but when the sealing material 40 is heated in the coating step, the The sealing material 40 is directly hardened by this heating. That is, in this case, the coating step and the hardening step can be performed simultaneously.

In addition, in this embodiment, the thermosetting resin composition is used as the sealing material 40 and the heat-expandable particles are used as the expanding particles. However, for example, the sealing material 40 may be composed of an energy ray-curable resin In the form of thermally expandable particles, the sealing material 40 may be an energy ray-curable resin composition, and the expandable particles may be energy ray-expandable particles. In these forms, the coating step and The thickness increase rate of the adhesive sheet 10 in the hardening step preferably satisfies the aforementioned range.

Specific examples of the temperature of heating the thermosetting resin composition in the coating step vary depending on the type of the sealing material 40 used, the type of the intumescent particles, etc., but may be, for example, 30 to 180° C., preferably 50 to 170° C. °C, more preferably 70 to 150 °C. Moreover, the heating time is, for example, 5 seconds to 60 minutes, preferably 10 seconds to 45 minutes, more preferably 15 seconds to 30 minutes. 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. When pressing the thermosetting resin composition under reduced pressure in the coating step, the pressure is, for example, 0.1 to 5.0 MPa, more preferably 0.5 to 4.0 MPa. In the aforementioned hardening step, a specific example of the temperature at which the sealing material 40 is hardened varies depending on the type of the sealing material 40 used, the type of intumescent particles, etc., but may be, for example, 80 to 240° C., preferably 90 to 200° C. , more preferably 100 to 170°C. Moreover, the heating time is, for example, 10 to 180 minutes, preferably 20 to 150 minutes, more preferably 30 to 120 minutes.

In the present embodiment, the coating step and the hardening step are preferably performed using a sheet-shaped sealing material (hereinafter also referred to as a "sheet-shaped sealing material"). In the method of using the sheet-like sealing material, the sheet-like sealing material is placed so as to cover the semiconductor wafer CP, its peripheral portion 30, and the frame member 20, and the semiconductor wafer CP, its peripheral portion 30, and the frame member 20 are covered with the sealing material 40. . At this time, it is preferable to heat and press with a vacuum laminator while appropriately reducing the pressure so that a portion of the gap between the semiconductor wafer CP and the frame member 20 that is not filled with the sealing material 40 does not occur. Preferable aspects of the reduced pressure, heating and pressing conditions are as described above. Subsequently, the laminated sealing material 40 is heat-hardened. The preferred aspect of the hardening temperature is as described above. The sheet-like sealing material may also be a laminated sheet supported by a resin sheet such as polyethylene terephthalate. In this case, after placing the laminated sheet so that the semiconductor wafer CP, its peripheral portion 30 , and the frame member 20 may be covered by the sheet-like sealing material, the resin sheet may be peeled off from the sealing material. In addition, when a sheet-like sealing material is used, after laminating the sheet-like sealing material, the first heating and pressing step may be performed before the thermosetting step. In the first heating and pressing step, the semiconductor wafer CP covered with the sealing material 40 and the adhesive sheet 10 are sandwiched by plate-like members from both sides and pressed under the conditions of specific temperature, time and pressure. By carrying out the 1st heating and pressurization process, the sealing material 40 is also easy to fill in the space|gap of the semiconductor wafer CP and the frame member 20. Moreover, the unevenness|corrugation of the sealing material layer which consists of the sealing material 40 can also be flattened by implementing a 1st heating and pressurization process. As the plate-like member, a metal plate such as stainless steel can be used.

Through the step (3), the hardening sealing body 50 in which the plurality of semiconductor chips CP are embedded in the hardening sealing material 41 is obtained. In addition, in steps (4) and (5) described later, after peeling the adhesive sheet 10 from the hardening 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, a reinforcing member may also be attached to the exposed surface of the hardened sealing body 50 (ie, the surface opposite to the intumescent base material) as required. Although it does not specifically limit as a reinforcement member, For example, the reinforcement board excellent in heat resistance, such as glass epoxy resin, is preferable, and it is preferable to bond a reinforcement board to the whole surface of the exposed surface of the hardening sealing body 50. The reinforcing member may be attached 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 off as necessary. The bonding of the reinforcing member can be performed by, for example, laminating a thermosetting adhesive layer and a reinforcing plate in sequence on the exposed surface of the hardened sealing body 50, and then, if necessary, from the two sides of the reinforcing plate side and the adhesive sheet side, respectively, with a plate. The 2nd heating and pressurizing step of pressurizing under the conditions of specific temperature, time and pressure is implemented by sandwiching the shaped member. In the second heating and pressurizing step, a metal plate such as stainless steel may be used as the plate-like member.

(Step (4)) FIG. 2(E) shows a cross-sectional view illustrating the step (4) of the expansion of the expandable particles and the peeling of the adhesive sheet 10 from the hardening sealing body 50 . Specifically, the intumescent particles are expanded by heat, energy rays, etc. depending on the type to 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 off. Step 4 is preferably carried out by fixing the surface 11a of the base material 11 on the opposite side of the adhesive layer 12 by fixing a jig or the like. By fixing the surface 11a, when the expandable particles are expanded, the unevenness can be suppressed from being formed on the surface 11a side, whereby the unevenness can be efficiently formed on the adhesive surface 12a side of the adhesive layer 12, and more excellent releasability can be obtained. As shown in Fig. 2(E), in this embodiment, as the aforementioned fixing jig, a suction stage 90 having a plurality of suction holes 91 is used to fix the surface 11a of the adhesive sheet 10. The suction stage 90 has a decompression mechanism such as a vacuum pump, and uses the decompression mechanism to suck the object from the plurality of suction holes 91 to fix the object on the suction surface.

In addition, the method of suppressing unevenness|corrugation on the surface 11a side of the base material 11 is not limited to the above-mentioned method, Any method which can physically suppress the unevenness|corrugation on the surface 11a side of the base material 11 can be used. As an example, it is the method of bonding a hard support body to the surface 11a via arbitrary adhesive layers, a double-sided adhesive sheet, etc., for example. The material of the rigid support can be appropriately determined in consideration of mechanical strength, heat resistance, etc. For example, metal materials such as SUS; non-metallic inorganic materials such as glass and silicon wafers; polyimide, polyimide amide Resin materials such as amines; composite materials such as glass epoxy resins, etc. The thickness of the hard support may be appropriately determined in consideration of mechanical strength, handleability, and the like, and is, for example, 100 μm to 50 mm. The adhesive layer (hereinafter also referred to as "second adhesive layer") used for lamination of the hard support is not particularly limited, but can be formed using the adhesive composition used for forming the adhesive layer 12. In addition, the second adhesive layer may be provided on the surface 11a side of the base material 11 in advance. Moreover, in this case, you may further have a peeling material on the adhesive surface of a 2nd adhesive bond layer. That is, the adhesive sheet 10 may have the composition of the adhesive layer 12/the base material 11/the second adhesive layer, or may have the composition of the release material/the adhesive layer 12/the base material 11/the second adhesive layer/the release material. constitute.

The method for expanding the expandable particles may be appropriately selected according to the type of the expandable particles. 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, as the "temperature above the expansion start temperature (t)", it is preferably not less than the "expansion start temperature (t) + 10°C" or more and "the expansion start temperature (t) + 60°C" or less, more preferably the "expansion start temperature (t) + 60°C" (t)+15°C" or more and "expansion start temperature (t)+40°C" or less. Specifically, according to the type of the heat-expandable particle, it may be heated to, for example, a range of 120 to 250° C. and expanded.

After the expandable particles expand, the adhesive sheet 10 is peeled off from the hardening sealing body 50 . Since the adhesive sheet 10 of the present embodiment has excellent peelability, it can be peeled off with a smaller external force than the conventional sheet for temporary fixation. The peeling method is not particularly limited, but for example, a method of peeling using a tape remover is exemplified.

In the manufacturing method of the present embodiment, in step (4), before or after peeling off the adhesive sheet 10 from the hardening sealing body 50, as required, the thickness of the hardening sealing body 50 may be reduced, and the hardening sealing body 50 may be ground and hardened. The step of the surface opposite to the rewiring layer forming surface of the body 50 .

(Step (5)) The manufacturing method of the present embodiment preferably includes a step (5) of forming a rewiring layer on the hardened sealing body 50 from which the double-sided adhesive sheet 10 has been peeled off. FIG. 3(A) shows a cross-sectional view of the hardened sealing body 50 after peeling off the adhesive sheet 10. In this step, rewiring to connect to the circuits W2 of the exposed plural semiconductor chips CP is formed on the circuit surface W1 and on the surface 50a of the hardened sealing body 50 outside the region corresponding to the semiconductor chip 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 chip CP and the surface 50a of the hardened sealing body 50 . The first insulating layer 61 made of insulating resin is formed on the circuit surface W1 and the surface 50a so as to expose the circuit W2 of the semiconductor chip CP or the internal terminal electrodes W3 of the circuit W2. Examples of insulating resins include polyimide resins, polybenzoxazole resins, silicone resins, and the like. The material of the internal terminal electrode W3 is not limited as long as it is a conductive material, and examples thereof include metals such as gold, silver, copper, and aluminum, and alloys containing these metals.

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

FIG. 4(A) is a cross-sectional view showing the step of forming the second insulating layer 62 covering the rewiring 70 . The rewiring 70 has external electrode pads 70A for external terminal electrodes. Openings and the like are provided in the second insulating layer 62 to expose the external electrode pads 70A for external terminal electrodes. In this embodiment, the external electrode pads 70A are exposed in the region (region corresponding to the circuit surface W1 ) of the semiconductor wafer CP of the cured sealing body 50 and outside the region (the region corresponding to the surface 50a on the cured sealing body 50 ). Further, the rewiring 70 is formed on the surface 50a of the hardened sealing body 50 so that the external electrode pads 70A are arranged in an array. In this embodiment, since the external electrode pads 70A are 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 the step of connecting the external terminal electrode 80 to the external electrode pad 70A. External terminal electrodes 80 such as solder balls are placed on the external electrode pads 70A exposed from the second insulating layer 62, and the external terminal electrodes 80 and the external electrode pads 70A are electrically connected by soldering or the like. The material of the solder balls is not particularly limited, and examples thereof include lead-containing solder, lead-free solder, and the like.

(Cut-cutting step) FIG. 4(C) shows a cross-sectional view illustrating a step of singulating the hardened sealing body 50 to which the external terminal electrodes 80 are connected. In this step, the hardened sealing body 50 is singulated in units of semiconductor wafers CP. The method of dividing the hardened sealing body 50 into pieces is not particularly limited, and it can be implemented by cutting means such as a dicing saw. By dividing the cured sealing body 50 into pieces, the semiconductor device 100 of the semiconductor wafer CP unit is manufactured. The semiconductor device 100 in which the external terminal electrodes 80 are connected to the external electrode pads 70A that are fanned out to the region outside the semiconductor wafer CP as described above is manufactured as FOWLP, FOPLP, or the like.

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

In the present invention, the following examples are used to specifically describe the present invention, but the present invention is not limited to the following examples. In addition, the physical property values in the following production examples and examples are values measured by the following methods.

<Mass average molecular weight (Mw)> It was measured under the following conditions using a gel permeation chromatography apparatus (manufactured by TOSOH Co., Ltd., product name "HLC-8020"), and the value measured in terms of standard polystyrene was used. (Measurement conditions) ・Column: "TSK Guard Column HXL-L", "TSK gel G2500HXL", "TSK gel G2000HXL", and "TSK gel G1000HXL" (all manufactured by TOSOH Co., Ltd.) connected in this order.・Column temperature: 40℃ ・Developing solvent: Tetrahydrofuran ・Flow rate: 1.0mL/min

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

<Average particle size (D ₅₀ ), 90% particle size (D ₉₀ ) of thermally expandable particles> Using a laser diffraction particle size distribution analyzer (for example, made by Malvern, product name "Mastersizer 3000"), the temperature at 23°C was measured. Particle distribution of thermally expandable particles prior to expansion. Next, the cumulative volume frequency calculated from the smaller particle size of the particle distribution corresponds to 50% and 90% of the particle size as the "average particle size of thermally expandable particles (D ₅₀ )" and "the average particle size of thermally expandable particles (D 50 )", respectively. 90% particle size (D ₉₀ )”.

<Storage modulus E' of the intumescent substrate> When the measurement object is a non-adhesive intumescent substrate, the intumescent substrate is made into a size of 5 mm in length x 30 mm in width x 200 μm in thickness, and the one with the release material removed is taken as test sample. Using a dynamic viscoelasticity measuring device (manufactured by TA Instrument, product name "DMAQ800"), the specific measurement was carried out under the conditions of a test start temperature of 0°C, a test end temperature of 300°C, a heating rate of 3°C/min, a vibration frequency of 1 Hz, and an amplitude of 20 μm. Storage modulus E' of the test sample at temperature.

<Shear storage modulus G' of the adhesive layer, storage modulus E' of the intumescent adhesive layer> When the measurement object is an intumescent adhesive layer and an adhesive layer with adhesive properties, the intumescent adhesive The layer and the adhesive layer were made into a diameter of 8 mm×thickness of 3 mm, and the release material was removed as a test sample. Using a viscoelasticity measuring device (manufactured by Anton Paar, device name "MCR300"), under the conditions of a test start temperature of 0°C, a test end temperature of 300°C, a heating rate of 3°C/min, and a vibration frequency of 1 Hz, the shearing method was performed by twisting. The shear storage modulus G' of the test samples at the specified temperature was 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 formula "E'=3G'".

<Probe Adhesion Value> After cutting the intumescent substrate or intumescent adhesive layer to be measured into a square of 10 mm on one side, it was left to stand for 24 hours in an environment of 23°C and 50% RH (relative humidity). The light peeling film was removed as a test sample. The aforementioned test samples were measured at 23°C and 50% RH (relative humidity) using a TACKING tester (manufactured by Nippon Special Instruments Co., Ltd., product name "NTS-4800"), and measured according to JIS Z0237: 1991 after removing light. The probe tack value of the surface of the test sample exposed by peeling off the film. Specifically, after 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, it was determined that the probe was separated from the surface of the test sample at a speed of 10 mm/sec. force. Next, the measured value was used as the probe viscosity value of the test sample.

The details of the adhesive resin, additives, heat-expandable particles, and release material used in the following production examples are as follows. <Adhesive resin> ・Acrylic copolymer (i): Contains a raw material 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 as a constituent unit of the monomer. Dilution solvent: ethyl acetate, solid content concentration: 40% by mass.・Acrylic copolymer (ii): containing a compound derived from n-butyl acrylate (BA) / methyl methacrylate (MMA) / 2-hydroxyethyl acrylate (HEA) / acrylic acid = 86.0/8.0/5.0/1.0 ( A solution of an acrylic copolymer having a mass average molecular weight (Mw) of 600,000 as a constituent unit of the raw material monomers. Dilution solvent: ethyl acetate, solid content concentration: 40% by mass. <Additive> ・Isocyanate crosslinking agent (i): Tosoh Co., Ltd. make, product name "Coronate L", solid content concentration: 75 mass %.・Photopolymerization initiator (i): BASF Corporation, product name "IRGACURE 184", 1-hydroxy-cyclohexyl-phenyl ketone. <Heat-expandable particles> ・Heat-expandable particles (i): manufactured by KURARAY Co., Ltd., product name "S2640", expansion start temperature (t) = 208°C, average particle size (D ₅₀ ) = 24 μm, 90% particle size ( D ₉₀ )=49 μm. <Release material> ・Heavy release film: LINTEK Co., Ltd., product name "SP-PET382150", on one side of a polyethylene terephthalate (PET) film, a silicone-based release agent is provided. For the release agent layer, thickness: 38 μm.・Light release film: manufactured by LINTEK Co., Ltd., product name "SP-PET381031", a release agent layer formed of a silicone-based release agent is provided on one side of the PET film, thickness: 38 μm.

Production Example 1 (Formation of Adhesive Layer (X)) To 100 parts by mass of the solid content of the above-mentioned acrylic copolymer (i) of the adhesive resin, 5.0 parts by mass of the above-mentioned isocyanate-based crosslinking agent (i) (solid content) was prepared 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, on the surface of the release agent layer of the re-release film, the prepared composition (x-1) was applied to form a coating film, and the coating film was dried at 100° C. for 60 seconds to form an adhesive layer (x-1) with a thickness of 10 μm. X). Moreover, the shear storage modulus G'(23) of the adhesive layer (X) at 23 degreeC was 2.5*10< ⁵ >Pa.

Production Example 2 (Formation of Intumescent Base Material (Y-1)) (1) Preparation of Composition (y-1) in Terminal Isocyanate Amine Obtained by Reacting Ester Diol with Isophorone Diisocyanate (IPDI) The formate prepolymer was reacted with 2-hydroxyethyl acrylate to obtain a bifunctional urethane acrylate oligomer with a mass average molecular weight (Mw) of 5000. Next, 40 mass % (solid content ratio) of isobornyl acrylate (IBXA) as an energy ray polymerizable monomer was prepared in 40 mass % (solid content ratio) of the urethane acrylate oligomer synthesized above. and phenylhydroxypropyl acrylate (HPPA) 20 mass % (solid content ratio), relative to 100 mass parts of the total amount of urethane acrylate oligomer and energy ray polymerizable monomer, and further prepared as a photopolymerization starter 1-Hydroxycyclohexyl phenyl ketone (manufactured by BASF Corporation, product name "IRGACURE 184") 2.0 parts by mass (solid content ratio) and 0.2 mass part (solid content ratio) of phthalocyanine pigment as an additive as the starting agent, the energy was adjusted Linear hardening composition. Next, the thermally expandable particles (i) described above are blended into the energy ray-curable composition to prepare a solvent-free composition (y-1) that does not contain a solvent. In addition, the content of the thermally expandable particles (i) relative to the total amount (100% by mass) of the composition (y-1) is 20% by mass.

(2) Intumescent base material (Y-1) is formed on the surface of the release agent layer of the above-mentioned 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, product name "ECS-401GX") and a high-pressure mercury lamp (manufactured by EYEGRAPHICS, product name "H04-L41"), under the conditions of illuminance of 160 mW/cm ² and light intensity of 500 mJ/cm ² The coating film was cured by irradiating ultraviolet rays to form an intumescent base material (Y-1) with a thickness of 50 μm. In addition, the said illuminance and light quantity at the time of ultraviolet irradiation are the values measured using an illuminance and light quantity meter (manufactured by EIT Corporation, product name "UV Power Puck II").

Production Example 3 (Formation of Intumescent Base Material (Y-2)) (1) Synthesis of Urethane Prepolymer In a reaction vessel under nitrogen atmosphere, carbonate with a mass average molecular weight (Mw) of 1,000 100 parts by mass (solid ratio) of type diol, isophorone diisocyanate is prepared in such a way that the equivalent ratio of the hydroxyl group of carbonate type diol and the isocyanate group of isophorone diisocyanate (IPDI) becomes 1/1, Furthermore, 160 parts by mass of toluene was added, and the reaction was carried out at 80° C. for 6 hours or more with stirring in a nitrogen atmosphere until the isocyanate group concentration reached the theoretical amount. Next, a solution of 1.44 parts by mass (solid content) of 2-ethylhexyl methacrylate (2-HEMA) diluted in 30 parts by mass of toluene was added, and the reaction was conducted at 80° C. for 6 hours until the isocyanate groups at both ends disappeared. A urethane prepolymer with a mass average molecular weight (Mw) of 29,000 was obtained.

(2) Synthesis of Acrylic Urethane Resin In a reaction vessel under nitrogen atmosphere, 100 parts by mass (solid content ratio) of the urethane prepolymer obtained in the above (1), methyl methacrylate were added 117 parts by mass of ester (MMA) (solid content ratio), 5.1 mass parts (solid content ratio) of 2-ethylhexyl acrylate (2-HEMA), 1.1 mass parts (solid content ratio) of 1-thioglycol, and toluene 50 parts by mass was heated to 105°C while stirring. Next, in the reaction vessel, a solution of 2.2 parts by mass (solid content ratio) of a radical initiator (manufactured by Japan Finechem Co., Ltd., product name "ABN-E") diluted with 210 parts by mass of toluene was further maintained at 105 The state of ℃ was dripped over 4 hours. After the dropwise addition, the reaction was carried out at 105°C for 6 hours to obtain a solution of urethane acrylate resin with a mass average molecular weight (Mw) of 105,000.

(3) Formation of intumescent base material (Y-2) With respect to 100 parts by mass of the solid content of the solution of the urethane acrylate resin obtained in the above (2), 6.3 mass parts of the above-mentioned isocyanate-based crosslinking agent (i) was prepared parts (solid content ratio), 1.4 parts by mass (solid content ratio) of dioctyltin bis(2-ethylhexanoate) as a catalyst, and the above-mentioned thermally expandable particles (i), diluted with toluene, uniformly stirred, and prepared The composition (y-2) with a solid content concentration (active ingredient concentration) of 30% by mass. In addition, the content of the heat-expandable particles (i) relative to the total amount (100% by mass) of the active ingredient in the obtained composition (y-2) was 20% by mass. Next, on the surface of the release agent layer of the above-mentioned light release film, the prepared composition (y-2) was applied to form a coating film, and the coating film was dried at 100° C. for 120 seconds to form an intumescent substrate with a thickness of 50 μm ( Y-2).

Production Example 4 (Formation of Intumescent Adhesive Layer (Y-3)) In 100 parts by mass of the solid content of the above-mentioned acrylic copolymer (ii) of the adhesive resin, 6.3 parts by mass of the above-mentioned isocyanate-based crosslinking agent (i) was prepared Part (solid content ratio) and the heat-expandable particle (i) were diluted with toluene and uniformly stirred to prepare a composition (y-3) having a solid content concentration (active ingredient concentration) of 30% by mass. In addition, the content of the heat-expandable particles (i) relative to the total amount (100% by mass) of the active ingredient in the obtained composition (y-3) was 20% by mass. Next, on the surface of the release agent layer of the light release film, the prepared composition (y-3) was applied to form a coating film, and the coating film was dried at 100° C. for 120 seconds to form an intumescent adhesive layer with a thickness of 50 μm (Y-3).

With respect to the intumescent base materials (Y-1) to (Y-2) formed in Production Examples 2 to 3 and the intumescent adhesive layer (Y-3) formed in Production Example 4, based on the above-mentioned method, the temperature was measured at 23° C. , 100°C and 208°C storage modulus E' and probe viscosity value 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 intumescent substrate (Y-1) formed in Production Example 2 were bonded to each other to produce a sequential laminated light release film/intumescent substrate ( Y-1)/Adhesive layer (X)/Adhesive sheet (1) of heavy release film.

Example 2 Except that the intumescent substrate (Y-1) was replaced by the intumescent substrate (Y-2) formed in Production Example 3, the same procedure as in Example 1 was carried out to produce a sequential laminated light release film/intumescent substrate (Y-2)/Adhesive layer (X)/Adhesive sheet (2) of heavy release film.

Comparative Example 1 In the same manner as in Example 1, except that the intumescent base material (Y-1) was replaced with the intumescent adhesive layer (Y-3) formed in Production Example 4, a sequential laminated light release film/intumescent adhesive was produced. 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 directly used as an adhesive sheet (4).

And the following measurement was performed about the produced adhesive sheets (1)-(4). These results are shown in Table 2.

<Evaluation of positional misalignment of semiconductor wafer during sealing step> The heavy release film is peeled off from the adhesive sheets (1) to (3) to expose the adhesive layer (X). On the adhesive surfaces of the adhesive layers (X) of the adhesive sheets (1) to (3) and the intumescent adhesive layer (Y-3) of the adhesive sheet (4), a specified number of openings of 10 mm × 10 mm are attached Part of the copper frame member. Next, remove the light release film from the adhesive sheets (1) to (4), and fix the exposed intumescent substrate or intumescent adhesive layer on the adsorption table with a plurality of adsorption holes as shown in FIG. 2(E). face. Next, on the adhesive surface exposed by the aforementioned plurality of openings, 9 semiconductor chips (chip size 6.4 mm×6.4 mm, chip size 6.4 mm×6.4 mm, chip size 6.4 mm×6.4 mm, chip size 6.4 mm×6.4 mm, chip size 6.4 mm×6.4 mm, chip size 6.4 mm×6.4 mm, chip size 6.4 mm×6.4 mm, chip size 6.4 mm×6. Thickness 200μm (#2000)). Then, a resin film (sealing material) for sealing is laminated on the adhesive surface, the frame member, and the semiconductor wafer, and the adhesive surface, the frame A member and a semiconductor wafer are hardened, and a hardened sealing body is produced. In addition, the sealing conditions are as follows.・Preheating temperature: 100℃ for both table and separator ・Evacuation: 60 seconds ・Dynamic pressing mode: 30 seconds ・Static pressing mode: 10 seconds ℃ low temperature) ・Sealing time: 60 minutes

After sealing, the adhesive sheets (1) to (4) are heated for 3 minutes at 240° C. higher than the expansion start temperature (208° C.) of the heat-expandable particles, and the hardened sealed body is separated from the adhesive sheets (1) to (4) to obtain a The semiconductor wafer on the surface (rewiring layer formation surface) of the separated hardened sealing body was observed visually and with a microscope to confirm whether or not the semiconductor wafer was displaced, and evaluated by the following criteria.・A: A semiconductor wafer with a position deviation of 25 μm or more from the position before sealing has not been confirmed.・F: A semiconductor wafer with a position deviation of 25 μm or more from the position before sealing was confirmed.

<Evaluation of Surface Flatness on the Semiconductor Wafer Side After the Sealing Step> Using the adhesive sheets (1) to (4), a cured sealing body was produced in the same procedure as in the above-mentioned "Evaluation of Positional Displacement of the Semiconductor Wafer During the Sealing Step". Separated from adhesive sheet. Using a contact surface roughness meter ("SV3000" manufactured by Mitutoyo Corporation), the level difference was measured on the surface of each semiconductor wafer side (rewiring layer forming surface) of the produced hardened sealing body, and evaluated by the following criteria.・A: A portion where a level difference of 2 μm or more occurred was not confirmed.・F: It is confirmed that a level difference of 2 μm or more occurs.

<Measurement of the adhesive force of the adhesive sheet before and after heating> For those who are ready to remove the heavy release film of the adhesive sheets (1) to (3) and the adhesive sheet (4), separate the adhesive layer (X) or the intumescent adhesive layer (Y). -3) The stainless steel plate (polished SUS304 No. 360) attached to the adhesive body was left standing for 24 hours under the environment of 23°C and 50%RH (relative humidity) as a test sample. Next, using the above-mentioned test sample, in an environment of 23°C, 50% RH (relative humidity), according to JIS Z0237:2000, by the 180° peeling method, the adhesive force at 23°C was measured at a tensile speed of 300 mm/min. . In addition, the above-mentioned test sample was heated on a hot plate for 3 minutes at 240°C, which is the expansion start temperature (208°C) or higher of the thermally expandable particles, and was allowed to stand in a standard environment (23°C, 50% RH (relative humidity)). 60 minutes later, based on JIS Z0237:2000, the adhesive force after heating above the expansion start temperature was measured by the 180° peeling method at a tensile speed of 300 mm/min. In addition, when it cannot be attached to the stainless steel plate of the adhesive body and it is difficult to measure the adhesive force, it is called "unmeasured", and the adhesive force is 0 (N/25mm).

As can be seen from Table 2, according to the manufacturing methods using the adhesive sheets (1) and (2) of Examples 1 and 2, during the heating during the sealing step, since the subsidence suppression effect of the semiconductor wafer is high, the semiconductor wafer is not seen. When the position is shifted, the surface on the side of the semiconductor wafer (the rewiring layer formation surface) 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 decreased to an unmeasurable level after heating above the expansion start temperature, so it was confirmed that the peeling can be easily peeled off with only a little force. 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 intumescent substrates, and because they have an intumescent adhesive layer, during the heating during the sealing step, the semiconductor wafer is damaged. When immersed, the positional deviation of the semiconductor wafer was observed, and the level difference was observed on the surface (the rewiring layer formation surface) on the side of the semiconductor wafer after the sealing step. Therefore, it is considered unsuitable for use in sealing steps in the manufacture of eg FOWLP and FOPLP.

10‧‧‧Double-sided Adhesive Sheet 11‧‧‧Substrate 11a‧‧‧Side 12‧‧‧Adhesive Layer 12a‧‧‧Adhesive Surface 13‧‧‧Peeling Material 20‧‧‧Frame Member 21‧‧‧Opening 30‧‧‧Semiconductor chip peripheral portion in the adhesive surface of the adhesive layer 40‧‧‧Sealing material 41‧‧‧Curing sealing material 50‧‧‧Curing sealing body 50a‧‧‧Side 61‧‧‧First insulating layer 62 ‧‧‧Second insulating layer 70‧‧‧Rewiring 70A‧‧‧External electrode pad 80‧‧‧External terminal electrode 90‧‧‧Suction stage 91‧‧‧Suction hole 100‧‧‧Semiconductor device CP‧‧‧ Semiconductor chip 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 of the present embodiment. Fig. 2 is a cross-sectional view illustrating an example of the manufacturing method of the present embodiment. FIG. 3 is a cross-sectional view illustrating an example of the manufacturing method of the present embodiment following FIG. 2 . Fig. 4 is a cross-sectional view illustrating an example of the manufacturing method of the present embodiment following Fig. 3 .

10‧‧‧Double-sided adhesive sheet

11‧‧‧Substrate

11a‧‧‧surface

12‧‧‧Adhesive layer

12a‧‧‧Adhesive surface

20‧‧‧Frame member

21‧‧‧Opening

30‧‧‧The peripheral part of the semiconductor chip in the adhesive surface of the adhesive layer

40‧‧‧Sealing material

41‧‧‧hardened sealant

50‧‧‧hardened seal

90‧‧‧Adsorption table

91‧‧‧Adsorption hole

CP‧‧‧Semiconductor Chip

W1‧‧‧circuit surface

Claims (11)

A method for manufacturing a semiconductor device, which is a method for manufacturing a semiconductor device using an adhesive sheet, the adhesive sheet has: an adhesive layer, and a non-adhesive base material including intumescent particles, comprising the following steps (1) ~ (4), step (1): the step of attaching the frame member formed with the opening to the adhesive surface of the adhesive layer; step (2): placing the semiconductor wafer on the surface exposed in the opening of the frame member The 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 in the adhesive surface of the adhesive layer with a sealing material, so that the sealing Step (4): expanding the intumescent particles, and peeling the adhesive sheet from the hardening sealing body, at 23 The storage modulus E'(23) of the aforementioned base material in °C is 1.0×10 ⁶ Pa or more. The method for manufacturing a semiconductor device according to claim 1, further comprising the following step (5), step (5): a step of forming a rewiring layer on the cured sealing body from which the adhesive sheet is peeled off. 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 expand the adhesive. The step of peeling the sheet from the aforementioned hardened sealing body. The manufacturing method of the semiconductor device of Claim 3 whose expansion start temperature (t) of the said thermally expandable particle is 120-250 degreeC. The method for manufacturing a semiconductor device according to claim 4, wherein the substrate satisfies the following requirements (1) to (2), and requirement (1): a storage modulus E' of the substrate at 100° C. (100 ) is 2.0×10 ⁵ Pa or more; requirement (2): The storage modulus E′(t) of the base material at the expansion start temperature (t) of the thermally expandable particles is 1.0×10 ⁷ Pa or less. The method for producing a semiconductor device according to claim 1 or 2, wherein the intumescent particles have an average particle diameter before expansion at 23° C. of 3 to 100 μm. The method for manufacturing a semiconductor device according to claim 1 or 2, 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 claim 1 or 2, wherein, The ratio (substrate/adhesive layer) of the thickness of the said base material to the thickness of the said adhesive bond layer at 23 degreeC is 0.2 or more. The method for manufacturing a semiconductor device according to claim 1 or 2, 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 claim 1 or 2, wherein the probe tack value on the surface of the substrate is less than 50 mN/5 mm

. An adhesive sheet, the adhesive sheet used in the manufacturing method of a semiconductor device according to any one of claims 1 to 10, comprising in this order: an adhesive layer, and a non-adhesive base containing intumescent particles material.

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