Film for temporary fixation, laminate for temporary fixation, and method for manufacturing semiconductor device

Abstract

Disclosed is a film, for temporary fixation, used in order to temporarily fix a semiconductor member, which includes a plurality of bump electrodes on one main surface of a semiconductor substrate, to a support member on the main surface side. The minimum melt viscosity of the film for temporary fixation is 60,000 Pa•s or less. The storage elastic modulus at 25°C of a cured product when the film for temporary fixation is cured at 170°C for 1 hour is 300 MPa or greater.

Description

Temporary fixing film, temporary fixing laminate, and method for manufacturing semiconductor device

[0001] The present disclosure relates to a temporary fixing film, a temporary fixing laminate, and a method for manufacturing a semiconductor device.

[0002] In the manufacture of semiconductor devices, after an integrated circuit is incorporated into a semiconductor substrate such as a semiconductor wafer or semiconductor chip, the semiconductor member having the semiconductor substrate may be processed. The semiconductor member is typically processed while temporarily fixed to a support member, and then the semiconductor member is separated from the support member. For example, Patent Document 1 discloses a method in which a semiconductor member is temporarily fixed to a support member via a temporary fixing material layer, and the processed semiconductor member is separated from the support member by light irradiation.

[0003] International Publication No. 2020 / 111193

[0004] In the manufacture of a semiconductor device, a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate may be temporarily fixed to a support member on the side of the main surface (the main surface on which the plurality of bump electrodes are present). In this case, the temporary fixing material layer is required to be able to sufficiently embed the plurality of bump electrodes (excellent bump embeddability) and to be able to easily peel the temporary fixing material layer from the semiconductor member after processing while suppressing the generation of residues (excellent peelability).

[0005] However, conventional temporary fixing material layers are not capable of achieving both high levels of bump embedding properties and high levels of peelability, and there is still room for improvement.

[0006] A main object of the present disclosure is to provide a temporary fixing film that is capable of forming a temporary fixing material layer that has excellent bump embedding properties and releasability.

[0007] The present inventors conducted research to solve the above-mentioned problems and found that bump embeddability and peelability can be improved by ensuring that the minimum melt viscosity before curing and the storage modulus at 25°C after curing of the temporary fixing film satisfy certain conditions, and thus completed the invention of the present disclosure.

[0008] The present disclosure provides a temporary fixing film according to [1] to [5], a temporary fixing laminate according to [6], and a method for manufacturing a semiconductor device according to [7] to [9]. [1] A temporary fixing film used to temporarily fix a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate to a support member on the main surface side, the temporary fixing film having a minimum melt viscosity of 60,000 Pa s or less, and a storage modulus at 25°C of 300 MPa or more of the cured product when the temporary fixing film is cured under conditions of 170°C and 1 hour. [2] The temporary fixing film according to [1], having a minimum melt viscosity of 20,000 Pa s or more. [3] The temporary fixing film according to [1] or [2], having a storage modulus at 25°C of 500 MPa or less. [4] The temporary fixing film according to any of [1] to [3], containing an acrylic rubber, an epoxy resin, and a phenolic resin. [5] The temporary fixing film according to any one of [1] to [3], which contains an acrylic rubber having an epoxy group and a phenolic resin. [6] A temporary fixing laminate comprising, in this order, a support member, a light absorbing layer, and a temporary fixing material layer made of the temporary fixing film according to any one of [1] to [5]. [7] A method for manufacturing a semiconductor device, comprising: a step of preparing the temporary fixing laminate according to [6]; a step of temporarily fixing a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate to the support member via the temporary fixing material layer, with the main surface facing the temporary fixing material layer; a step of processing the semiconductor member temporarily fixed to the support member; a step of irradiating the light absorbing layer of the temporary fixing laminate from the support member side with light to separate a laminate made of the processed semiconductor member and the temporary fixing material layer from the support member; and a step of peeling the temporary fixing material layer from the processed semiconductor member in the laminate, thereby obtaining the processed semiconductor member. [8] The method for manufacturing a semiconductor device according to [7], wherein the light is light including at least infrared light. [9] The method for manufacturing a semiconductor device according to [8], wherein the light is incoherent light.

[0009] According to the present disclosure, there is provided a temporary fixing film capable of forming a temporary fixing material layer having excellent bump embedding properties and releasability. Also, according to the present disclosure, there is provided a temporary fixing laminate using the temporary fixing film. Furthermore, according to the present disclosure, there is provided a method for manufacturing a semiconductor device using the temporary fixing laminate.

[0010] Fig. 1 is a schematic cross-sectional view showing one embodiment of a temporary fixing film. Fig. 2 is a schematic cross-sectional view showing one embodiment of a temporary fixing laminate. Figs. 3(a), 3(b), and 3(c) are schematic cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device. Figs. 4(a), 4(b), and 4(c) are schematic cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device. Figs. 5(a) and 5(b) are schematic cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as appropriate. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including steps, etc.) are not essential unless specifically stated. The sizes of the components in each figure are conceptual, and the relative size relationships between the components are not limited to those shown in each figure.

[0012] The same applies to the numerical values ​​and ranges in the present disclosure, and do not limit the present disclosure. In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit value of that numerical range may be replaced with the value shown in the Examples (Production Examples).

[0013] In this specification, the term "layer" includes not only a structure with a shape formed over the entire surface when observed in a plan view, but also a structure with a shape formed on a portion of the surface. Furthermore, in this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved.

[0014] In this specification, (meth)acrylate means acrylate or its corresponding methacrylate, and the same applies to other similar expressions such as (meth)acryloyl group, (meth)acrylic copolymer, etc.

[0015] In this specification, unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more within the range that meets the conditions. When multiple substances corresponding to each component are present, the content of each component means the total amount of the multiple substances unless otherwise specified.

[0016] [Temporary Fixing Film] Fig. 1 is a schematic cross-sectional view showing one embodiment of a temporary fixing film. The temporary fixing film 2A shown in Fig. 1 is used to temporarily fix a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate to a support member on the main surface side. More specifically, the temporary fixing film 2A is used to form a layer (temporary fixing material layer) for temporarily fixing a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate to a support member on the main surface side during processing of the semiconductor member in the manufacture of a semiconductor device. The temporary fixing film 2A may be thermosetting and may be capable of passing through a semi-cured (B-stage) state and then becoming fully cured (C-stage) after a curing treatment.

[0017] B-stage refers to an intermediate stage in the reaction of certain thermosetting resins where the material swells when in contact with certain liquids and softens when heated, but does not completely dissolve or melt; C-stage refers to the final stage in the reaction of certain thermosetting resins where the material becomes virtually insoluble and infusible.

[0018] According to the studies of the inventors of the present disclosure, it has been found that when the minimum melt viscosity of the temporary fixing film 2A before curing (for example, in a semi-cured (B stage) state) is 60,000 Pa·s or less, it tends to be possible to sufficiently embed multiple bump electrodes (excellent bump embeddability).

[0019] The minimum melt viscosity of the temporary fixing film 2A may be, for example, 55,000 Pa s or less, 50,000 Pa s or less, 45,000 Pa s or less, or 40,000 Pa s or less. From the viewpoint of improving wettability and avoiding difficulty in peeling, the lower limit of the minimum melt viscosity of the temporary fixing film 2A may be, for example, 5,000 Pa s or more, 10,000 Pa s or more, 15,000 Pa s or more, or 20,000 Pa s or more.

[0020] In this specification, the minimum melt viscosity of the temporary fixing film 2A before curing can be measured as follows. First, an 80 μm temporary fixing film is prepared, and multiple sheets are laminated using a rubber roll on a hot plate at 80°C to obtain a laminate with a thickness of 960 μm. The obtained laminate is cut into a circular shape with a diameter of 9 mm to prepare a measurement sample. The prepared measurement sample is attached to a measurement jig of a rotational viscoelasticity measuring device (for example, an ARES-G2 (manufactured by TA Instruments Japan Co., Ltd.)), and viscoelasticity is measured under the following conditions. The minimum value of the viscosity (complex viscosity) within the measurement temperature range is read, thereby deriving the minimum melt viscosity.

[0021] (Measurement conditions) Measurement jig: parallel plate, aluminum, φ8 mm Frequency: 1 Hz Heating rate: 8°C / min Strain: 5% Measurement temperature: 35 to 160°C

[0022] Furthermore, according to studies by the inventors of the present disclosure, it has been found that when the temporary fixing film 2A is cured under conditions of 170°C and 1 hour, if the storage modulus at 25°C of the cured product (the temporary fixing film 2A after curing (for example, in a completely cured (C-stage) state)) is 300 MPa or more, problems such as heavy peeling due to the use of energy for elongation during peeling, or the film being too soft and breaking during peeling to leave residue can be suppressed, and as a result, there is a tendency for the temporary fixing material layer to be easily peeled off from the semiconductor member after processing (excellent peelability) while suppressing the generation of residue.

[0023] The storage modulus of the cured temporary fixing film 2A at 25° C. may be, for example, 320 MPa or more or 350 MPa or more. The upper limit of the storage modulus of the cured temporary fixing film 2A at 25° C. may be, for example, 1000 MPa or less, 800 MPa or less, 600 MPa or less, or 500 MPa or less.

[0024] In this specification, the storage modulus at 25°C of the cured temporary fixing film 2A can be measured as follows. First, an 80 μm temporary fixing film is prepared, and multiple sheets are laminated to obtain a laminate with a thickness of 240 μm. Next, the obtained laminate is cured using a constant temperature air-blowing dryer at 170°C for 1 hour to obtain a cured temporary fixing film. A measurement sample is prepared by cutting the obtained cured product into a size of 4 mm wide x 30 mm long. The measurement sample is placed in a dynamic viscoelasticity measuring device (e.g., Rheogel E-4000 (manufactured by UBM Corporation)), and viscoelasticity is measured under a tensile load in a temperature dependency measurement mode under conditions of a frequency of 10 Hz, a heating rate of 3°C / min, and a temperature range of -30 to 300°C. The value at 25°C is read, and the storage modulus at 25°C is derived.

[0025] Next, we will explain each component constituting the temporary fixing film 2 A. By using such each component, it tends to be easy to adjust the minimum melt viscosity of the temporary fixing film 2 A before curing and the storage modulus at 25° C. of the temporary fixing film 2 A after curing to within a predetermined range.

[0026] One embodiment of the temporary fixing film 2A may contain, for example, acrylic rubber (hereinafter sometimes referred to as "component (A)"), epoxy resin (hereinafter sometimes referred to as "component (B)"), and phenolic resin (hereinafter sometimes referred to as "component (C)"), and may further contain a curing accelerator (hereinafter sometimes referred to as "component (D)"), an inorganic filler (hereinafter sometimes referred to as "component (E)"), other components, etc.

[0027] Component (A): Acrylic Rubber Component (A) may contain structural units derived from a (meth)acrylic acid ester as a main component. Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate. The content of the structural units derived from a (meth)acrylic acid ester may be, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total amount of structural units constituting component (A).

[0028] The component (A) may contain, as a structural unit derived from a (meth)acrylic acid ester, a structural unit derived from a (meth)acrylic acid ester having a crosslinkable functional group such as an epoxy group (glycidyl group), an alcoholic or phenolic hydroxyl group, or a carboxyl group. The crosslinkable functional group may be, for example, an epoxy group (glycidyl group). Examples of (meth)acrylic acid esters having a crosslinkable functional group include glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate. Among these, the (meth)acrylic acid ester having a crosslinkable functional group may be glycidyl (meth)acrylate.

[0029] The content of the structural unit derived from a (meth)acrylic acid ester having a crosslinkable functional group may be, for example, 1% by mass or more, 3% by mass or more, 5% by mass or more, or 7% by mass or more, based on the total amount of structural units constituting the component (A). By using an acrylic rubber having a high content of structural units derived from a (meth)acrylic acid ester having a crosslinkable functional group as the component (A), it tends to be easier to adjust the minimum melt viscosity of the temporary fixing film before curing and the storage modulus at 25°C of the temporary fixing film after curing to within a predetermined range. The content of the (meth)acrylic acid ester having a crosslinkable functional group (particularly, an epoxy group (glycidyl group)) may be, for example, 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less, based on the total amount of structural units constituting the component (A).

[0030] The component (A) may further contain structural units derived from acrylonitrile in addition to structural units derived from a (meth)acrylic acid ester, or may not contain structural units derived from acrylonitrile.

[0031] The glass transition temperature (Tg) of the component (A) may be -40°C or higher, -35°C or higher, or -30°C or higher, and may be 50°C or lower, 30°C or lower, or 10°C or lower. When the Tg of the component (A) is -40°C or higher, it tends to be easier to adjust the minimum melt viscosity of the temporary fixing film before curing and the storage modulus at 25°C of the temporary fixing film after curing to within predetermined ranges. When the Tg of the component (A) is 50°C or lower, it tends to be easier to ensure the flexibility of the temporary fixing film more sufficiently.

[0032] The Tg of component (A) refers to the midpoint glass transition temperature of component (A) measured using a differential scanning calorimeter (DSC). The midpoint glass transition temperature can be calculated, for example, by measuring the change in calorific value at a temperature rise rate of 10°C / min at a measurement temperature of -80 to 80°C using a method in accordance with JIS K 7121:2012.

[0033] The weight average molecular weight (Mw) of the component (A) may be 100,000 to 1,200,000, 200,000 to 1,000,000, or 300,000 to 800,000. When the Mw of the component (A) is 100,000 or more, the heat resistance of the temporary fixing film tends to be easily ensured. When the Mw of the component (A) is 1,200,000 or less, the flexibility of the temporary fixing film tends to be more easily ensured.

[0034] The Mw of component (A) refers to a polystyrene equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0035] The content of the (A) component may be 40 to 80% by mass, based on the total amount of the temporary fixing film. The content of the (A) component may be 45% by mass or more, 50% by mass or more, or 55% by mass or more, based on the total amount of the temporary fixing film, and may be 75% by mass or less, 70% by mass or less, or 65% by mass or less. When the content of the (A) component is 40% by mass or more, based on the total amount of the temporary fixing film, film handleability tends to be easily maintained. When the content of the (A) component is 80% by mass or less, based on the total amount of the temporary fixing film, the minimum melt viscosity of the temporary fixing film before curing and the storage modulus at 25°C of the temporary fixing film after curing tend to be easily adjusted within predetermined ranges.

[0036] Component (B): Epoxy Resin Component (B) can be any epoxy resin that has an epoxy group in the molecule. Examples of epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, bisphenol A novolac epoxy resins, bisphenol F novolac epoxy resins, stilbene epoxy resins, triazine epoxy resins, fluorene epoxy resins, triphenolmethane epoxy resins, biphenyl epoxy resins, xylylene epoxy resins, biphenyl aralkyl epoxy resins, naphthalene epoxy resins, and diglycidyl ether compounds of polyfunctional phenols or polycyclic aromatics. Among these, component (B) may contain cresol novolac epoxy resin.

[0037] The (B) component may contain a solid epoxy resin that is solid at 30°C (an epoxy resin with a softening point exceeding 40°C), or may consist of a solid epoxy resin that is solid at 30°C (an epoxy resin with a softening point exceeding 40°C). When the (B) component contains a solid epoxy resin that is solid at 30°C, the minimum melt viscosity of the temporary fixing film before curing and the storage modulus at 25°C of the temporary fixing film after curing tend to be easily adjusted to a predetermined range. In this specification, the softening point of the epoxy resin refers to a value measured by the ring and ball method in accordance with JIS K7234:1986. The softening point of the solid epoxy resin that is solid at 30°C may be, for example, 50°C or higher or 70°C or higher, or 150°C or lower or 120°C or lower.

[0038] The epoxy equivalent of the component (B) is not particularly limited, but may be 90 to 350 g / eq or 110 to 320 g / eq. When the epoxy equivalent of the component (B) is in such a range, there is a tendency that the bulk strength of the temporary fixing film can be maintained while ensuring fluidity.

[0039] Component (C): Phenolic Resin Component (C) is not particularly limited as long as it has a phenolic hydroxyl group in the molecule. Examples of phenolic resins include novolac phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol and / or naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthalene with a compound having an aldehyde group such as formaldehyde under an acidic catalyst; phenol aralkyl resins and naphthol aralkyl resins synthesized from phenols such as allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, and / or naphthols with dimethoxyparaxylene or bis(methoxymethyl)biphenyl; and the like. Among these, component (C) may contain a novolac phenolic resin.

[0040] The component (C) may contain a phenolic resin having a softening point exceeding 90°C, or may consist of a phenolic resin having a softening point exceeding 90°C. When the component (C) contains a phenolic resin having a softening point exceeding 90°C, the minimum melt viscosity of the temporary fixing film before curing and the storage modulus at 25°C of the temporary fixing film after curing tend to be easily adjusted to within a predetermined range. In this specification, the softening point of the phenolic resin means a value measured by the ring and ball method in accordance with JIS K6910:2007. The softening point of a phenolic resin having a softening point exceeding 90°C may be, for example, 95°C or higher, 100°C or higher, or 110°C or higher, or 160°C or lower, or 140°C or lower.

[0041] The hydroxyl group equivalent of the component (C) may be 70 to 300 g / eq or 90 to 250 g / eq. When the hydroxyl group equivalent of the component (C) is 70 g / eq or more, the storage modulus of the temporary fixing film tends to be further improved. When the hydroxyl group equivalent of the component (C) is 300 g / eq or less, foaming within the temporary fixing film tends to be suppressed.

[0042] From the viewpoint of curability, the ratio of the epoxy equivalent of the component (B) to the hydroxyl equivalent of the component (C) (epoxy equivalent of the component (B) / hydroxyl equivalent of the component (C)) may be 0.30 / 0.70 to 0.70 / 0.30, 0.35 / 0.65 to 0.65 / 0.35, 0.40 / 0.60 to 0.60 / 0.40, or 0.45 / 0.55 to 0.55 / 0.45. When the equivalent ratio is within such a range, it tends to be easier to adjust the minimum melt viscosity of the temporary fixing film before curing and the storage modulus at 25°C of the temporary fixing film after curing to within predetermined ranges.

[0043] The total content of the (B) component and the (C) component may be 20 to 70 parts by mass, 25 to 60 parts by mass, or 30 to 55 parts by mass, based on 100 parts by mass of the total amount of the (A) component. When the total content of the (B) component and the (C) component is 20 parts by mass or more, based on 100 parts by mass of the total amount of the (A) component, the storage modulus tends to be further improved by crosslinking. When the total content of the (B) component and the (C) component is 70 parts by mass or less, based on 100 parts by mass of the total amount of the (A) component, the film handleability tends to be easily maintained.

[0044] Component (D): Curing Accelerator Examples of the component (D) include imidazole derivatives, dicyandiamide derivatives, dicarboxylic acid dihydrazides, triphenylphosphine, tetraphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazole-tetraphenylborate, and 1,8-diazabicyclo[5,4,0]undecene-7-tetraphenylborate.

[0045] The content of the (D) component may be, for example, 0.1 parts by mass or more, 0.3 parts by mass or more, or 0.5 parts by mass or more, relative to 100 parts by mass of the total amount of the (A), (B), and (C) components. By increasing the content of the (D) component, it tends to be easier to adjust the minimum melt viscosity of the temporary fixing film before curing and the storage modulus at 25°C of the temporary fixing film after curing to fall within a predetermined range. The content of the (D) component may be, for example, 5 parts by mass or less, 3 parts by mass or less, or 2 parts by mass or less, relative to 100 parts by mass of the total amount of the (A), (B), and (C) components.

[0046] Component (E): Inorganic Filler Examples of component (E) include metal fillers such as silver powder, gold powder, and copper powder; and non-metal fillers such as silica, alumina, boron nitride, titania, glass, and ceramic. Metal fillers can be added to the resin layer for the purpose of imparting thixotropy, etc. Non-metal fillers can be added to the resin layer for the purpose of imparting heat resistance, releasability, low thermal expansion, low moisture absorption, etc. Component (E) may be a non-metal filler, such as silica. From the viewpoint of dispersibility in a solvent, component (E) may be particles whose surfaces have been treated with a surface treatment agent. The surface treatment agent may be, for example, a silane coupling agent.

[0047] From the viewpoint of fluidity, the average particle size of the component (E) may be 0.01 μm (10 nm) or more, 0.02 μm (20 nm) or more, or 0.03 μm (30 nm) or more, and may be 1.0 μm (1000 nm) or less, 0.5 μm (500 nm) or less, or 0.2 μm (200 nm) or less. The component (E) may be a combination of two or more components (E) having different average particle sizes. Here, the average particle size refers to the particle size at a cumulative frequency of 50% in the particle size distribution determined by a laser diffraction / scattering method. The average particle size of the component (E) can also be determined by using a temporary fixing film containing the component (E). In this case, the temporary fixing film is heated to decompose the resin component, and the resulting residue is dispersed in a solvent to prepare a dispersion. The average particle size of the component (E) can be determined from the particle size distribution obtained by applying the laser diffraction / scattering method to the dispersion.

[0048] The content of component (E) may be 5 to 300 parts by mass, 10 to 100 parts by mass, or 20 to 50 parts by mass, based on 100 parts by mass of the total amount of component (A). When the content of the inorganic filler is within this range, heat resistance tends to be further improved. Furthermore, when the content of the inorganic filler is within this range, it may also contribute to easy releasability.

[0049] The temporary fixing film may further contain other components such as an organic filler, a sensitizer, an antioxidant, a surfactant, and a release agent.

[0050] Examples of organic fillers include carbon, rubber-based fillers, silicone-based fine particles, polyamide fine particles, polyimide fine particles, etc. The content of the organic filler may be 1 to 100 parts by mass per 100 parts by mass of the total amount of component (A).

[0051] Examples of sensitizers include anthracene, phenanthrene, chrysene, benzopyrene, fluoranthene, rubrene, pyrene, xanthone, indanthrene, thioxanthene-9-one, 2-isopropyl-9H-thioxanthene-9-one, 4-isopropyl-9H-thioxanthene-9-one, 1-chloro-4-propoxythioxanthone, etc. The amount of sensitizer included may be 0.1 to 20 parts by mass, relative to 100 parts by mass of the total amount of component (A).

[0052] Examples of antioxidants include quinone derivatives such as benzoquinone and hydroquinone, phenol derivatives (hindered phenol derivatives) such as 4-methoxyphenol and 4-t-butylcatechol, aminoxyl derivatives such as 2,2,6,6-tetramethylpiperidine-1-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and hindered amine derivatives such as tetramethylpiperidyl methacrylate. The content of the antioxidant may be 0.1 to 20 parts by mass per 100 parts by mass of the total amount of component (A).

[0053] Examples of surfactants include silicone surfactants, fluorine-based surfactants, amphoteric surfactants, nonionic surfactants, anionic surfactants, etc. The content of the surfactant may be 0.1 to 20 parts by mass per 100 parts by mass of the total amount of component (A).

[0054] Another embodiment of the temporary fixing film 2A may contain, for example, an elastomer having a crosslinkable functional group such as an epoxy group (glycidyl group), an alcoholic or phenolic hydroxyl group, a carboxyl group, etc., and a curing agent capable of reacting with the crosslinkable functional group. Examples of the combination of an elastomer having a crosslinkable functional group and a curing agent capable of reacting with the crosslinkable functional group include a combination of an acrylic rubber having an epoxy group and a phenolic resin.

[0055] Examples of the acrylic rubber having an epoxy group include the same as the above-mentioned component (A) (acrylic rubber including, as a structural unit derived from a (meth)acrylic acid ester, a structural unit derived from a (meth)acrylic acid ester having an epoxy group). The content of the acrylic rubber having an epoxy group may be 40 to 80% by mass, based on the total amount of the temporary fixing film. The content of the component (A) may be 45% by mass or more, 50% by mass or more, or 55% by mass or more, and may be 75% by mass or less, 72% by mass or less, or 70% by mass or less, based on the total amount of the temporary fixing film.

[0056] Examples of the phenolic resin include those similar to those of component (C) above. The content of the phenolic resin may be 5 to 60 parts by mass, 10 to 40 parts by mass, or 15 to 30 parts by mass relative to 100 parts by mass of the total amount of the acrylic rubber having an epoxy group.

[0057] Other embodiments of the temporary fixing film 2A may further contain a curing accelerator, an inorganic filler, other components, and the like.

[0058] Examples of the curing accelerator include those similar to those of the above-mentioned component (D). The content of the curing accelerator may be, for example, 0.1 parts by mass or more, 0.3 parts by mass or more, or 0.5 parts by mass or more, and 5 parts by mass or less, 3 parts by mass or less, or 2 parts by mass or less, relative to 100 parts by mass of the total amount of the epoxy group-containing acrylic rubber and the phenolic resin.

[0059] Examples of the inorganic filler include those similar to those of component (E) above. The content of the inorganic filler may be, for example, 5 to 300 parts by mass, 10 to 100 parts by mass, or 20 to 50 parts by mass relative to 100 parts by mass of the total amount of the epoxy group-containing acrylic rubber.

[0060] Examples of the other components include the same components as those mentioned above (organic filler, sensitizer, antioxidant, surfactant, mold release agent, etc.).

[0061] From the viewpoint of bump embedding properties, the thickness of the temporary fixing film 2A may be, for example, 10 μm or more, 30 μm or more, or 50 μm or more, and may be 500 μm or less, 300 μm or less, or 100 μm or less.

[0062] According to the temporary fixing film 2A of this embodiment, it is possible to form a temporary fixing material layer that is excellent in bump embedding properties and releasability.

[0063] [Method for Producing Temporary Fixing Film] The temporary fixing film 2A can be obtained, for example, by the following procedure. First, the above-mentioned components are dissolved or dispersed in a solvent by stirring, mixing, kneading, or the like to prepare a varnish of the temporary fixing film-forming composition. The varnish of the temporary fixing film-forming composition is then applied to a support film that has been subjected to a release treatment using a knife coater, roll coater, applicator, comma coater, die coater, or the like, and the solvent is then volatilized by heating to form a temporary fixing film 2A made of the temporary fixing film-forming composition on the support film. The temporary fixing film 2A may further include a protective film laminated on the surface opposite to the support film. The thickness of the temporary fixing film 2A can be adjusted by adjusting the coating amount of the varnish of the temporary fixing film-forming composition.

[0064] The solvent used in preparing the varnish of the temporary fixing film-forming composition is not particularly limited as long as it has the property of being able to uniformly dissolve or disperse each component. Examples of such solvents include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Among these, the solvent may be toluene, xylene, heptane, or cyclohexanone from the viewpoints of solubility and boiling point. The solids concentration in the varnish may be 10 to 80% by mass based on the total mass of the varnish.

[0065] The stirring, mixing or kneading when preparing the varnish of the temporary fixing film-forming composition can be carried out using, for example, a stirrer, a kneading machine, a three-roll mill, a ball mill, a bead mill, a homodisper or the like.

[0066] Examples of the support film include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene and polypropylene; polycarbonate, polyamide, polyimide, polyamideimide, polyetherimide, polyethersulfide, polyethersulfone, polyetherketone, polyphenylene ether, polyphenylene sulfide, poly(meth)acrylate, polysulfone, and liquid crystal polymer films. These support films may be subjected to a release treatment. The thickness of the support film may be, for example, 1 to 250 μm.

[0067] The heating conditions for volatilizing the solvent from the varnish of the temporary fixing film-forming composition applied to the support film can be appropriately set according to the solvent to be used, etc. The heating conditions may be, for example, a heating temperature of 40 to 120°C for a heating time of 0.1 to 30 minutes.

[0068] The protective film may be the same as the above-mentioned examples of the support film, and the thickness of the protective film may be, for example, 1 to 250 μm.

[0069] [Temporary Fixing Laminate and Manufacturing Method Thereof] Fig. 2 is a schematic cross-sectional view showing one embodiment of a temporary fixing laminate 10. The temporary fixing laminate 10 shown in Fig. 2 includes, in this order, a support member 4, a light absorbing layer 6, and a temporary fixing material layer 2 made of the temporary fixing film 2A.

[0070] The support member 4 is a plate-like body that has high transmittance and can withstand the load applied during processing of the semiconductor member. Examples of the support member 4 include an inorganic glass substrate and a transparent resin substrate.

[0071] The thickness of the support member 4 may be, for example, 0.1 to 2.0 mm. If the thickness of the support member 4 is 0.1 mm or more, handling tends to be easier. If the thickness of the support member 4 is 2.0 mm or less, material costs tend to be reduced.

[0072] The light absorbing layer 6 may be, for example, a layer that absorbs light and generates heat when irradiated with light. If the light absorbing layer 6 is a layer that absorbs light and generates heat, when light is irradiated to the light absorbing layer 6, the light absorbing layer 6 generates heat, causing the light absorbing layer 6 to melt, etc., and it becomes possible to efficiently separate the support member 4 and the temporary fixing material layer 2 through interfacial peeling, cohesive peeling, etc. at the interface or bulk of the light absorbing layer 6. The light that is absorbed by the light absorbing layer 6 may be light that contains either infrared light (e.g., light with a wavelength of 780 to 2500 nm), visible light, or ultraviolet light (e.g., light with a wavelength of 200 to 380 nm), or may be light that contains either infrared light or ultraviolet light, or may be light that contains infrared light.

[0073] The light absorbing layer 6 can be a light absorbing layer having a conventionally known composition and structure, depending on the type of light to be absorbed.

[0074] When the light to be absorbed includes at least infrared light, the light absorption layer 6 may be, for example, a conductive layer made of a conductor that absorbs light and generates heat. Examples of conductors that make up the conductive layer include metals, metal oxides, and conductive carbon materials. The metal may be a simple metal such as chromium, copper, titanium, silver, platinum, or gold, or may be an alloy such as nickel-chromium, stainless steel, or copper-zinc. Examples of metal oxides include indium tin oxide (ITO), zinc oxide, and niobium oxide.

[0075] The light absorbing layer 6 may be a single layer or multiple conductive layers. When the light absorbing layer 6 is a single conductive layer, the light absorbing layer 6 may contain at least one metal selected from the group consisting of tantalum (Ta), platinum (Pt), nickel (Ni), titanium (Ti), tungsten (W), chromium (Cr), copper (Cu), aluminum (Al), silver (Ag), and gold (Au).

[0076] The light-absorbing layer 6 may be composed of two conductive layers, a first layer and a second layer, stacked in this order from the support member 4 side. In this case, for example, if the first layer has high light absorption and the second layer has a high thermal expansion coefficient and a high elastic modulus, good peelability tends to be obtained. From this perspective, the first layer of the light-absorbing layer 6 may contain at least one metal selected from the group consisting of tantalum (Ta), platinum (Pt), nickel (Ni), titanium (Ti), tungsten (W), and chromium (Cr), and the second layer of the light-absorbing layer 6 may contain at least one metal selected from the group consisting of copper (Cu), aluminum (Al), silver (Ag), and gold (Au).

[0077] In one embodiment, the thickness of the light absorbing layer 6 may be 1 to 5000 nm (0.001 to 5 μm) or 50 to 3000 nm (0.05 to 3 μm) from the viewpoint of good peelability.

[0078] When the light absorbing layer 6 is a single layer or multiple conductive layers, the thickness of the light absorbing layer 6 may be 75 nm or more, 90 nm or more, or 100 nm or more, and may be 1000 nm or less, 800 nm or less, 500 nm or less, or 300 nm or less, from the viewpoint of good peelability. When the light absorbing layer 6 is a single conductive layer, the thickness of the light absorbing layer 6 may be 100 nm or more, 125 nm or more, 150 nm or more, or 200 nm or more, and may be 1000 nm or less, 800 nm or less, or 500 nm or less, from the viewpoint of good peelability.

[0079] In other embodiments, the thickness of the light absorbing layer 6 may be, for example, 0.1 μm or more, 1 μm or more, or 5 μm or more, and may be 100 μm or less, 50 μm or less, or 30 μm or less, from the viewpoint of good peelability.

[0080] The temporary fixing material layer 2 is a layer made of a temporary fixing film 2 A. From the viewpoint of bump embeddability, the thickness of the temporary fixing material layer 2 may be, for example, 10 μm or more, 30 μm or more, or 50 μm or more, and may be 500 μm or less, 300 μm or less, or 100 μm or less.

[0081] The method for producing the temporary fixing laminate 10 is not particularly limited as long as it can produce a temporary fixing laminate 10 having a predetermined configuration. When the light absorbing layer 6 is a conductive layer made of a conductive material that absorbs light and generates heat, the temporary fixing laminate 10 can be produced, for example, by a method including a step of forming the light absorbing layer 6 on the support member 4 and a step of attaching the temporary fixing film 2A onto the formed light absorbing layer 6.

[0082] The light absorbing layer 6 (a conductive layer made of a conductor that absorbs light and generates heat) can be obtained by forming a metal layer on the support member 4 by physical vapor deposition (PVD) such as vacuum deposition or sputtering, or chemical vapor deposition (CVD) such as plasma-enhanced chemical vapor deposition. The light absorbing layer 6 (a conductive layer made of a conductor that absorbs light and generates heat) can also be obtained by forming a plating layer on the support member 4 by electrolytic plating or electroless plating. Physical vapor deposition makes it possible to efficiently form the light absorbing layer 6 that covers the surface of the support member 4, even if the support member 4 has a large area.

[0083] Examples of a method for attaching the temporary fixing film 2A onto the light absorbing layer 6 (a conductive layer made of a conductive material that absorbs light and generates heat) include heat pressing, roll lamination, vacuum lamination, etc. Lamination can be performed under a temperature condition of 0 to 120°C, for example.

[0084] [Method for manufacturing semiconductor device] A method for manufacturing a semiconductor device according to one embodiment includes the steps of: preparing the temporary fixing laminate (preparation step); temporarily fixing a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate to the support member via the temporary fixing material layer with the main surface facing the temporary fixing material layer (temporary fixing step); processing the semiconductor member temporarily fixed to the support member (processing step); irradiating the light absorbing layer of the temporary fixing laminate with light from the support member side to separate the laminate including the processed semiconductor member and the temporary fixing material layer from the support member (separation step); and peeling the temporary fixing material layer from the processed semiconductor member in the laminate to obtain the processed semiconductor member (peeling step).

[0085] (Preparation Step) In the preparation step, the temporary fixing laminate 10 is prepared for temporarily fixing a semiconductor member to a support member while the semiconductor member is being processed in order to manufacture a semiconductor device.

[0086] 3(a), 3(b), and 3(c) are schematic cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device. In the temporary fixing step, a semiconductor member 20 having a plurality of bump electrodes 22 on one main surface S1 of a semiconductor substrate 24 is temporarily fixed to the support member 4 via the temporary fixing material layer 2, with the main surface S1 facing the temporary fixing material layer 2. The temporary fixing material layer 2 has a surface S2 opposite to the light absorbing layer 6 of the temporary fixing material layer 2. In the temporary fixing step, for example, the semiconductor member 20 is placed on the surface S2 of the temporary fixing material layer 2 with the main surface S1 facing the temporary fixing material layer 2 (see FIG. 3(a)), and the temporary fixing material layer 2 (temporary fixing film 2A) is thermally cured in a state in which the semiconductor member 20 is placed on the temporary fixing material layer 2 (see FIG. 3(b)). This allows the semiconductor member 20 to be temporarily fixed to the support member 4 (see FIG. 3(c)). In other words, the semiconductor member 20 can be temporarily adhered to the support member 4 via the temporary fixing material layer 2c containing the cured product of the temporary fixing film 2A. Furthermore, the temporary fixing material layer 2 is made of the temporary fixing film 2A, and can sufficiently embed the multiple bump electrodes 22 of the semiconductor member 20. In this way, a laminate 30 is formed that includes the temporary fixing laminate 10c and the semiconductor member 20 provided on the temporary fixing laminate 10c.

[0087] The semiconductor member 20 has a semiconductor substrate 24 and a plurality of bump electrodes 22 provided on one main surface S1 of the semiconductor substrate 24. The semiconductor member 20 may have bump electrodes provided on both main surfaces of the semiconductor substrate 24 (main surface S1 and the main surface opposite to main surface S1). The semiconductor member 20 may further have external connection terminals. The semiconductor substrate 24 may be a semiconductor wafer or a semiconductor chip obtained by dividing a semiconductor wafer. The thickness of the semiconductor substrate 24 may be 1 to 1000 μm, 10 to 500 μm, or 20 to 200 μm from the viewpoints of miniaturizing and thinning the semiconductor device as well as suppressing cracking during transportation and processing. The height of the bump electrodes 22 may be 5 to 150 μm, 7.5 to 125 μm, or 10 to 100 μm from the viewpoint of bump embeddability. From the viewpoint of bump embeddability, the width of the bump electrode 22 may be 1 to 100 μm, 3 to 80 μm, or 5 to 60 μm. From the viewpoint of bump embeddability, the distance between adjacent bump electrodes 22 may be 5 to 150 μm, 7.5 to 125 μm, or 10 to 100 μm.

[0088] The semiconductor member 20 can be arranged by, for example, using a flip chip bonder or the like, by pressure bonding onto the temporary fixing material layer 2. The pressure bonding conditions may be a pressure bonding temperature (head side) of 60 to 180°C or 80 to 150°C, a pressure bonding pressure of 0.01 to 1.5 MPa or 0.1 to 1.0 MPa, and a holding time of 1 to 600 seconds or 1 to 300 seconds.

[0089] After the semiconductor member 20 is placed on the temporary fixing material layer 2, the temporary fixing material layer 2 (temporary fixing film 2A) is thermally cured, whereby the semiconductor member 20 is temporarily fixed to the support member 4 via the temporary fixing material layer 2c containing the cured product of the temporary fixing film 2A. The thermal curing conditions may be, for example, in an air atmosphere, at 300°C or lower or at 100 to 250°C, and for 1 to 180 minutes or 1 to 120 minutes. When the temporary fixing material layer 2 (temporary fixing film 2A) is thermally cured, for example, a heating and pressure treatment device may be used to heat the semiconductor member 20 placed on the temporary fixing material layer 2 (temporary fixing film 2A) while applying pressure. The pressure conditions may be 0.01 to 1.5 MPa or 0.1 to 1.0 MPa.

[0090] 4(a), 4(b), and 4(c) are schematic cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device. In the processing step, the semiconductor member 20 temporarily fixed to the support member 4 is processed. Examples of processing of the semiconductor member include thinning the semiconductor substrate, dividing the semiconductor member (dicing), forming a through electrode (through-silicon electrode), etching, plating reflow, sputtering, or a combination thereof.

[0091] After processing the semiconductor member 20 (semiconductor substrate 24), an encapsulating layer 26 may be formed to encapsulate the processed semiconductor member 20a (processed semiconductor substrate 24a) (see FIG. 4(a)). The encapsulating layer 26 can be formed using an encapsulating material typically used in the manufacture of semiconductor devices. For example, the encapsulating layer 26 may be formed from a thermosetting resin composition. Examples of thermosetting resin compositions used for the encapsulating layer 26 include epoxy resins such as cresol novolac epoxy resin, phenol novolac epoxy resin, biphenyl diepoxy resin, and naphthol novolac epoxy resin. The encapsulating layer 26 and the thermosetting resin composition for forming the encapsulating layer 26 may contain additives such as a filler and / or a flame retardant.

[0092] The sealing layer 26 is formed using, for example, a solid material, a liquid material, a granular material, or a sealing film. When a sealing film is used, a compression sealing molding machine, a vacuum laminating machine, or the like is used. For example, using these machines, the sealing layer 26 can be formed by covering the semiconductor member 20 with a sealing film that has been heat-melted under conditions of 40 to 180°C (or 60 to 150°C), 0.1 to 10 MPa (or 0.5 to 8 MPa), and 0.5 to 10 minutes. The thickness of the sealing film is adjusted so that the sealing layer 26 is equal to or greater than the thickness of the semiconductor member 20a after processing. The thickness of the sealing film may be 50 to 2000 μm, 70 to 1500 μm, or 100 to 1000 μm.

[0093] Curing of the sealing layer 26 (Post Mold Cure (PMC)) can be carried out, for example, in air or in an inert gas. The curing temperature may be, for example, 80 to 280°C, 100 to 240°C, or 120 to 200°C. The curing time may be, for example, 30 to 600 minutes, 45 to 300 minutes, or 60 to 240 minutes.

[0094] After the sealing layer 26 is formed, the sealing layer 26 and the temporary fixing material layer 2c may be divided into a plurality of parts each including one semiconductor member 20.

[0095] (Separation process) In the separation process, light A is irradiated onto the light absorbing layer 6 of the temporary fixing laminate 10c from the support member 4 side, and a laminate 40 consisting of the processed semiconductor member 20a and the temporary fixing material layer 2c is separated from the support member 4.

[0096] If the light absorbing layer 6 is a layer that absorbs light A and generates heat, the light absorbing layer 6 generates heat when irradiated with light, causing the light absorbing layer 6 to melt, etc., and it becomes possible to efficiently separate the support member 4 and the temporary fixing material layer 2 through interfacial peeling, cohesive peeling, etc. at the interface or bulk of the light absorbing layer 6. In order to separate the laminate 40 from the support member 4, a slight stress may be applied to the laminate 40 in addition to the irradiation with light A.

[0097] The light A in the separation step may be light containing any of infrared light, visible light, or ultraviolet light, or may be light containing either infrared light or ultraviolet light, or may be light containing infrared light.

[0098] The light A in the separation step may be coherent light. Coherent light is an electromagnetic wave with properties such as high coherence, high directionality, and high monochromaticity. Coherent light tends to have high intensity because light of the same wavelength and in-phase is reinforced and combined. Laser light is generally coherent light.

[0099] The light source of the coherent light may be a laser, including, for example, a solid-state laser such as a YAG laser, a liquid laser such as a dye laser, a gas laser such as an excimer laser, a semiconductor laser, and a fiber laser.

[0100] The laser irradiation conditions include the applied voltage, pulse width, irradiation time, irradiation distance (the distance between the light source and the light absorption layer 6), irradiation energy, etc., and these can be set arbitrarily depending on the number of irradiations, etc. From the viewpoint of reducing damage to the semiconductor member 20, the laser irradiation conditions may be set so that the processed semiconductor member 20a can be separated with fewer irradiations.

[0101] The light A in the separation process may be incoherent light. Incoherent light is non-coherent light, an electromagnetic wave with properties such as no interference fringes, low coherence, and low directivity. Incoherent light tends to attenuate as the optical path length increases. Light such as sunlight and fluorescent light is incoherent light. Incoherent light can also be considered light excluding laser light. The irradiation area of ​​incoherent light is generally much larger than that of coherent light (i.e., laser light), so the number of irradiations can be reduced. For example, a single irradiation can cause separation of multiple semiconductor members 20. The incoherent light may be pulsed light. It is preferable to irradiate the entire surface of the support member with incoherent light.

[0102] The light source of the incoherent light is not particularly limited, but may be a xenon lamp. A xenon lamp is a lamp that utilizes light emission caused by application and discharge in an arc tube filled with xenon gas. A xenon lamp discharges while repeatedly ionizing and exciting, and therefore stably emits a continuous range of wavelengths from the ultraviolet to the infrared region. Xenon lamps require a shorter start-up time than lamps such as metal halide lamps, and therefore can significantly reduce the time required for the process. Furthermore, although light emission requires the application of a high voltage, which generates high heat instantaneously, xenon lamps are also advantageous in that they have a short cooling time and allow for continuous operation.

[0103] The irradiation conditions of the xenon lamp include the applied voltage, pulse width, irradiation time, irradiation distance (the distance between the light source and the light absorbing layer), irradiation energy, etc., and these can be set arbitrarily depending on the number of irradiations, etc. From the viewpoint of reducing damage to the semiconductor member 20, the irradiation conditions may be set so that the processed semiconductor member 20a can be separated by a single irradiation.

[0104] 5( a) and 5(b) are schematic cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device. In the peeling step, in the laminate 40, the temporary fixing material layer 2c is peeled off from the processed semiconductor member 20a, thereby obtaining the processed semiconductor member 20a. The temporary fixing material layer 2c may be peeled off, for example, by peeling. The temporary fixing material layer 2c is made of a cured product of the temporary fixing film 2A, and it becomes possible to easily peel the temporary fixing material layer from the processed semiconductor member while suppressing the generation of residues.

[0105] The above-described exemplary method can provide a processed semiconductor member 20 a. For example, the semiconductor device 50 can be manufactured by connecting the processed semiconductor member 20 a to a semiconductor member mounting substrate 28.

[0106] The present disclosure will be specifically described below based on examples, but the present disclosure is not limited to these examples.

[0107] (Production Example 1) [Synthesis of Acrylic Rubber P-1] In a 500 mL separable flask equipped with a stirrer, a thermometer, a nitrogen replacement device (nitrogen inlet pipe), and a reflux condenser with a water receiver, 200 g of deionized water, 70 g of butyl acrylate, 9.5 g of methyl methacrylate, 10 g of glycidyl methacrylate, 10 g of 2-hydroxyethyl methacrylate, 0.5 g of styrene, 2.04 g of a 1.8 mass % aqueous polyvinyl alcohol solution, 0.41 g of lauryl peroxide, and 0.07 g of n-octyl mercaptan were blended. Subsequently, the mixture was stirred for 60 minutes. ２After blowing gas into the system to remove air, the temperature in the system was raised to 65°C and stirred for 3 hours, and then further raised to 90°C and stirred for 2 hours to complete the polymerization. The resulting transparent beads were separated by filtration, washed with deionized water, and then dried in a vacuum dryer at 50°C for 6 hours to obtain acrylic rubber P-1. When acrylic rubber P-1 was measured by GPC, the Mw of acrylic rubber P-1 was 500,000 in polystyrene equivalent value. The Tg of acrylic rubber P-1 was also -28°C.

[0108] The Mw of acrylic rubber P-1 was measured using GPC (SD-8022 / DP-8020 / RI-8020, manufactured by Tosoh Corporation) with tetrahydrofuran as an eluent and Gelpack GL-A150-S / GL-A160-S, manufactured by Showa Denko Materials Co., Ltd., as a column.

[0109] The Tg of the acrylic rubber P-1 was determined by measuring the change in heat quantity using a differential scanning calorimetry (DSC) (DSC8230, manufactured by Rigaku Corporation) at a temperature rise rate of 10°C / min and a measurement temperature range of -80 to 80°C, and calculating the midpoint glass transition temperature by a method in accordance with JIS K 7121:1987. The calculated midpoint glass transition temperature was designated as the Tg of the acrylic rubber P-1.

[0110] (Production Example 2) [Synthesis of Acrylic Rubber P-2] In a 500 mL separable flask equipped with a stirrer, a thermometer, a nitrogen replacement device (nitrogen inlet pipe), and a reflux condenser with a water receiver, 200 g of deionized water, 20 g of butyl acrylate, 31.1 g of butyl methacrylate, 4.5 g of glycidyl methacrylate, 18.6 g of 2-ethylhexyl methacrylate, 25.8 g of dicyclopentanyl acrylate, 2.04 g of a 1.8 mass % aqueous polyvinyl alcohol solution, 0.41 g of lauryl peroxide, and 0.07 g of n-octyl mercaptan were blended. Subsequently, the mixture was stirred for 60 minutes. ２After blowing gas into the system to remove air, the temperature in the system was raised to 65°C and stirred for 3 hours, and then further raised to 90°C and stirred for 2 hours to complete the polymerization. The resulting transparent beads were separated by filtration, washed with deionized water, and then dried in a vacuum dryer at 50°C for 6 hours to obtain acrylic rubber P-2. When the Mw of acrylic rubber P-2 was measured in the same manner as for the Mw of acrylic rubber P-1, the Mw of acrylic rubber P-2 was 500,000 in polystyrene equivalent. Furthermore, when the Tg of acrylic rubber P-2 was measured in the same manner as for the Tg of acrylic rubber P-1, the Tg of acrylic rubber P-2 was 6.5°C.

[0111] Example 1 [Production of Temporary Fixing Film] <Preparation of Raw Materials> The following raw materials were prepared. Component (A): Acrylic rubber A-1: ​​Acrylic rubber P-1 of Production Example 1 (content of (meth)acrylic ester having epoxy groups: 10% by mass (based on the total amount of structural units) A-2: Acrylic rubber P-2 of Production Example 2 (content of (meth)acrylic ester having epoxy groups: 4.5% by mass (based on the total amount of structural units)) Component (B): Epoxy resin B-1: N-500P-10 (trade name, manufactured by DIC Corporation, o-cresol novolac epoxy resin, epoxy equivalent: 203 g / eq, softening point: 80 to 87°C (solid at 25°C)) Component (C): Phenolic resin C-1: PSM-4326 (trade name, manufactured by Gun-ei Chemical Co., Ltd., phenol novolac resin, hydroxyl equivalent: 105 g / eq, softening point: 118 to 122°C (solid at 25°C)) Component (D): Curing accelerator D-1: 2PZ-CN (trade name, manufactured by Shikoku Chemicals Corporation, 1-cyanoethyl-2-phenylimidazole) Component (E): inorganic filler E-1: YA-050C-HHG (trade name, manufactured by Admatechs Co., Ltd., silica surface-treated with vinylsilane, average particle size: 0.05 μm (50 nm)) Component (F): surfactant F-1: FZ-2162 (trade name, manufactured by Dow Corning Toray Silicone Co., Ltd., silicone surfactant)

[0112] <Preparation of Temporary Fixing Film> The components were blended in the composition ratios (unit: parts by mass) shown in Table 1, and cyclohexanone was added. The components were stirred until uniform, to prepare a varnish of the composition for forming a temporary fixing film. The prepared varnish was filtered through a 100-mesh filter and vacuum-degassed. The vacuum-degassed resin varnish was applied to a 38 μm-thick polyethylene terephthalate (PET) film that had been subjected to a release treatment, which served as a support film. The applied varnish was then heated and dried in two stages: at 90°C for 5 minutes and then at 140°C for 5 minutes, to prepare the 80 μm-thick temporary fixing film of Example 1 on the support film. In the temporary fixing film, a PET film similar to the support film was placed as a protective film on the surface opposite the support film.

[0113] <Measurement of Minimum Melt Viscosity> The minimum melt viscosity of the temporary fixing film of Example 1 before curing was measured as follows. First, a plurality of 80 μm-thick temporary fixing films of Example 1 were laminated on a hot plate at 80°C using a rubber roll to obtain a laminate with a thickness of 960 μm. The obtained laminate was cut into a circular shape with a diameter of 9 mm to prepare a measurement sample. The prepared measurement sample was attached to a measurement jig of a rotational viscoelasticity measuring device (e.g., ARES-G2 (manufactured by TA Instruments Japan Co., Ltd.)), and viscoelasticity was measured under the following conditions. The minimum value of viscosity (complex viscosity) within the measurement temperature range was read, thereby deriving the minimum melt viscosity. The results are shown in Table 1. The minimum melt viscosity temperature was determined as the temperature at which the viscosity showed a minimum value based on the relationship between the viscosity (complex viscosity) obtained in the above viscoelasticity measurement and temperature. In other words, the temperature at which the viscosity was minimum within the measurement temperature range was defined as the minimum melt viscosity temperature. The obtained minimum melt viscosity temperature results are also shown in Table 1.

[0114] (Measurement conditions) Measurement jig: parallel plate, aluminum, φ8 mm Frequency: 1 Hz Heating rate: 8°C / min Strain: 5% Measurement temperature: 35 to 160°C

[0115] <Measurement of Storage Modulus> The storage modulus at 25°C of the cured temporary fixing film of Example 1 was measured as follows. First, multiple 80 μm-thick temporary fixing films of Example 1 were laminated to obtain a 240 μm-thick laminate. The resulting laminate was then cured at 170°C for 1 hour using a constant temperature air dryer to obtain a cured temporary fixing film. A measurement sample was prepared by cutting the resulting cured product into a size of 4 mm wide x 30 mm long. The measurement sample was placed in a dynamic viscoelasticity measuring device (e.g., Rheogel E-4000, manufactured by UBM Corporation). Viscoelasticity was measured under a tensile load in a temperature dependency measurement mode under conditions of a frequency of 10 Hz, a heating rate of 3°C / min, and a temperature range of -30 to 300°C. The value at 25°C was read, and the storage modulus at 25°C was calculated. The results are shown in Table 1.

[0116] <Evaluation of Bump Embeddability> A 1.5 cm x 1.5 cm inorganic glass plate (Eagle XG, manufactured by Corning Incorporated, thickness 0.7 mm) was prepared, and one main surface of the inorganic glass plate was treated with a fluorine release agent (Daifree GA-9700, Daikin Industries, Ltd.). The 80 μm thick temporary fixing film of Example 1 was attached to the main surface of the inorganic glass plate treated with the fluorine release agent, to obtain a laminate A including an inorganic glass plate and a temporary fixing material layer provided on the inorganic glass plate. Subsequently, a semiconductor member having a plurality of bump electrodes on one main surface of the semiconductor substrate (WALTS-TEG CC80TSV-0101JY, manufactured by Waltz Corporation, chip size: 7.3 mm x 7.3 mm, thickness: 0.1 mm, bump electrode (connection portion) height: approximately 45 μm (total of copper pillar and solder), number of bump electrodes: 1048 pins, pitch: (periphery) 80 μm zigzag, (center) 300 μm) was prepared, and a flip chip bonder (LFB-2301, manufactured by Shinkawa Co., Ltd.) was used to bond the laminate A and the semiconductor member in a direction in which the main surface having a plurality of bump electrodes of the semiconductor member is located on the temporary fixing material layer side. The bonding conditions were a bonding temperature (head temperature) of 130 ° C., a bonding temperature (stage temperature) of 30 ° C., a bonding pressure of 0.5 MPa, and a bonding time of 10 seconds. This resulted in a laminate B comprising an inorganic glass plate, a temporary fixing material layer, and a semiconductor member in this order. The obtained laminate B was pressurized in an automatic heating and pressure treatment device (ACS-450, manufactured by Chiyoda Electric Co., Ltd.) under an air atmosphere at 0.5 MPa, 170 ° C, and 1 hour, while being pressed, to cure the temporary fixing film. Subsequently, two 120 μm thick sealing films were used in a vacuum laminating device to cover the semiconductor member on the temporary fixing material layer under conditions of 70 ° C, 0.5 MPa, and 30 seconds, forming a sealing layer. The sealing layer was further subjected to PMC (Post Mold Cure) under conditions of 140 ° C and 120 minutes, to obtain an evaluation sample of Example 1. For the bump embeddability, the evaluation sample was cast in epoxy resin and polished until the portion where the bump electrodes were densely arranged around the periphery of the semiconductor member was exposed, and the exposed cross section was observed under a microscope and evaluated based on the following criteria. The results are shown in Table 1. A: The bump electrodes were embedded in the temporary fixing material layer (temporary fixing film) without any gaps.B: There was a small gap around the bump electrode, but the bump electrode was embedded in the temporary fixing material layer (temporary fixing film). C: There was a large gap around the bump electrode, and the bump electrode was not embedded in the temporary fixing material layer (temporary fixing film).

[0117] <Evaluation of Peelability> Peelability was evaluated using the evaluation sample of Example 1. The inorganic glass substrate was peeled from the evaluation sample of Example 1 to expose the temporary fixing material layer. Subsequently, a 1 cm wide support tape (Film Tape No. 6227, manufactured by Maxell, Ltd.) was attached to the surface of the exposed temporary fixing material layer to obtain an evaluation sample for evaluating peelability. The sealing layer side of the evaluation sample was fixed, and a peel test was performed by pulling the support tape at 25°C, a peel angle of 90°, and a peel rate of 63 mm / min. When peeling between the semiconductor member and the temporary fixing material layer was possible, the peelability was evaluated as excellent, and an "A" was given. When peeling between the semiconductor member and the temporary fixing material layer was not possible, for example, the support tape was torn, the "C" was given. When the evaluation was "A," it was visually evaluated whether residue of the temporary fixing material layer remained on the semiconductor member. The results are shown in Table 1.

[0118] (Example 2) The temporary fixing film of Example 1 was prepared and left to stand in a clean room at 23°C to age the temporary fixing film of Example 1 for two weeks, thereby obtaining a temporary fixing film of Example 2. The temporary fixing film of Example 2 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0119] (Example 3) A temporary fixing film of Example 3 was obtained in the same manner as in Example 2, except that the aging period was changed to 3 weeks. The temporary fixing film of Example 3 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0120] (Example 4) A temporary fixing film of Example 4 was obtained in the same manner as in Example 2, except that the aging period was changed to 4 weeks. The temporary fixing film of Example 4 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0121] (Example 5) A temporary fixing film of Example 5 was obtained in the same manner as in Example 2, except that the aging period was changed to 4.5 weeks. The temporary fixing film of Example 5 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0122] (Example 6) A temporary fixing film of Example 6 was obtained in the same manner as in Example 2, except that the aging period was changed to 5 weeks. The temporary fixing film of Example 6 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0123] (Example 7) A temporary fixing film of Example 7 was obtained in the same manner as in Example 2, except that the aging period was changed to 6 weeks. The temporary fixing film of Example 7 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0124] (Comparative Example 1) A temporary fixing film of Comparative Example 1 was obtained in the same manner as in Example 2, except that the aging period was changed to 7 weeks. The temporary fixing film of Comparative Example 1 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0125] (Example 8) A temporary fixing film of Example 8 was obtained in the same manner as in Example 1, except that the components were blended in the composition ratio (unit: parts by mass) shown in Table 2. The temporary fixing film of Example 8 was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0126] (Example 9) A temporary fixing film of Example 9 was obtained in the same manner as in Example 1, except that the components were blended in the composition ratio (unit: parts by mass) shown in Table 2. The temporary fixing film of Example 9 was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0127] (Comparative Example 2) A temporary fixing film of Comparative Example 2 was obtained in the same manner as in Example 1, except that the components were blended in the composition ratio (unit: parts by mass) shown in Table 2. The temporary fixing film of Comparative Example 2 was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0128] (Comparative Example 3) A temporary fixing film of Comparative Example 3 was obtained in the same manner as in Example 1, except that the components were blended in the composition ratio (unit: parts by mass) shown in Table 2. The temporary fixing film of Comparative Example 3 was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0129]

[0130]

[0131] As shown in Tables 1 and 2, the temporary fixing films of the examples, which satisfied the specified conditions for the minimum melt viscosity before curing and the storage modulus at 25°C after curing, had good both bump embeddability and releasability, whereas the temporary fixing films of the comparative examples, which did not satisfy these conditions, had poor either bump embeddability or releasability. These results confirmed that the temporary fixing film of the present disclosure can form a temporary fixing material layer that is excellent in bump embeddability and releasability.

[0132] 2, 2c...temporary fixing material layer, 2A...temporary fixing film, 4...support member, 6...light absorbing layer, 10, 10c...temporary fixing laminate, 20...semiconductor member, 20a...semiconductor member after processing, 22...bump electrode, 24...semiconductor substrate, 24a...semiconductor substrate after processing, 26...sealing layer, 28...semiconductor member mounting substrate, 30, 40...laminated body, 50...semiconductor device.

Claims

1. A temporary fixing film used to temporarily fix a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate to a support member on the main surface side, the temporary fixing film having a minimum melt viscosity of 60,000 Pa s or less, and a storage modulus at 25°C of 300 MPa or more when the temporary fixing film is cured at 170°C for 1 hour.

2. The temporary fixing film according to claim 1, wherein the minimum melt viscosity is 20,000 Pa·s or more.

3. The temporary fixing film according to claim 1 or 2, wherein the storage modulus at 25°C is 500 MPa or less.

4. The temporary fixing film according to claim 1 or 2, which contains acrylic rubber, epoxy resin, and phenolic resin.

5. The temporary fixing film according to claim 1 or 2, which contains an acrylic rubber having an epoxy group and a phenolic resin.

6. A temporary fixing laminate comprising, in this order, a support member, a light absorbing layer, and a temporary fixing material layer made of the temporary fixing film according to claim 1 or 2.

7. A method for manufacturing a semiconductor device, comprising the steps of: preparing a temporary fixing laminate according to claim 6; temporarily fixing a semiconductor member having a plurality of bump electrodes on one main surface of a semiconductor substrate to the support member via the temporary fixing material layer, with the main surface facing the temporary fixing material layer; processing the semiconductor member temporarily fixed to the support member; irradiating the light absorbing layer of the temporary fixing laminate with light from the support member side to separate a laminate consisting of the processed semiconductor member and the temporary fixing material layer from the support member; and peeling the temporary fixing material layer from the processed semiconductor member in the laminate, thereby obtaining the processed semiconductor member.

8. The method for manufacturing a semiconductor device according to claim 7, wherein the light includes infrared light.

9. The method for manufacturing a semiconductor device according to claim 8, wherein the light is incoherent light.

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