Adhesive tape for semiconductor, method for manufacturing adhesive tape for semiconductor, method for manufacturing semiconductor chip equipped with adhesive layer, and method for manufacturing semiconductor device

Abstract

The present invention discloses one example of an adhesive tape for a semiconductor. An adhesive tape 10 for a semiconductor comprises a base material 4, a pressure-sensitive adhesive layer 3 disposed on the base material 4, and an adhesive layer (film-like adhesive) 2 disposed on the pressure-sensitive adhesive layer. The arithmetic mean roughness Sa of the surface of the pressure-sensitive adhesive layer 3 on the side far from the base material 4 is 0.012 μm or less. Although the adhesive tape 10 for a semiconductor is integrated with a pressure-sensitive adhesive tape, the surface of the adhesive layer after removal of the pressure-sensitive adhesive tape exhibits satisfactory flatness.

Description

Adhesive Tape for Semiconductors, Method for Producing Adhesive Tape for Semiconductors, Method for Producing Semiconductor Chip with Adhesive Layer, and Method for Producing Semiconductor Device

[0001] The present disclosure relates to an adhesive tape for semiconductors, a method for producing an adhesive tape for semiconductors, a method for producing a semiconductor chip with an adhesive layer, and a method for producing a semiconductor device.

[0002] Conventionally, a wire bonding method using fine metal wires such as gold wires has been widely applied for connecting a semiconductor chip and a substrate. On the other hand, in order to meet the demands for higher functionality, higher integration, higher speed, and the like for semiconductor devices, a flip-chip connection method (FC connection method), in which conductive protrusions called bumps are formed on a semiconductor chip or a substrate and the semiconductor chip and the substrate are directly connected, is becoming widespread.

[0003] For example, regarding the connection between a semiconductor chip and a substrate, a COB (Chip On Board) type connection method that is actively used for BGA (Ball Grid Array), CSP (Chip Size Package), and the like also falls under the FC connection method. The FC connection method is also widely used in a COC (Chip On Chip) type connection method in which connection portions (e.g., bumps and wirings) are formed on semiconductor chips to connect the semiconductor chips to each other.

[0004] Recently, as one of high-density mounting technologies, a method of preparing a wafer with a film-like adhesive attached (semiconductor wafer with an adhesive layer) and using a semiconductor chip with an adhesive layer obtained from this wafer has been studied. Among these, Patent Document 1 proposes an adhesive tape for semiconductors in which a back grind tape and an adhesive layer are laminated for the purpose of simplifying the process. A semiconductor wafer with an adhesive layer can be obtained by attaching this adhesive tape for semiconductors to a wafer, performing polishing or the like on the wafer, and then peeling off the back grind tape.

[0005] Japanese Unexamined Patent Publication No. 2009-239138

[0006] In recent years, with the strong demand for further miniaturization, thinning, and enhanced functionality of packages, there has been progress in miniaturizing the bumps formed on semiconductor chips or substrates and narrowing the pitch between wirings. When forming such fine circuits, it is necessary not only to prevent the formation of voids between the semiconductor chip or substrate and the adhesive layer, but also to ensure that the adhesive layer can be embedded in the narrow pitch.

[0007] On the other hand, when using semiconductor adhesive tapes integrated with adhesive tapes such as backgrind tapes (also called "adhesive tape integrated semiconductor adhesive films"), minute irregularities (for example, irregularities of about 10 μm in diameter) tend to occur on the surface of the adhesive layer after the adhesive tape is peeled off, and there is room for improvement in terms of the flatness of the adhesive layer.

[0008] Therefore, one aspect of this disclosure aims to provide an adhesive tape for semiconductors that is integrated with the adhesive tape, yet exhibits good flatness on the surface of the adhesive layer after the adhesive tape has been peeled off.

[0009] The inventors first investigated the cause of minute irregularities on the surface of the adhesive layer after peeling off the adhesive tape in conventional adhesive tape-integrated semiconductor adhesive films, and obtained the following findings. Specifically, in the case of adhesive tape used in the manufacture of adhesive tape-integrated adhesive films, the surface of the adhesive layer is usually covered with a release film (separator) such as polyethylene terephthalate (PET) film from the viewpoint of protecting the surface of the adhesive layer. However, minute irregularities exist on the surface of the release film, and these irregularities are transferred to the surface of the adhesive layer. When the release film is peeled off from the adhesive tape and an adhesive layer is formed on the exposed adhesive layer, the irregularities on the surface of the adhesive layer are further transferred to the surface of the adhesive layer, resulting in insufficient flatness of the surface of the adhesive layer exposed after peeling off the adhesive tape.

[0010] Based on the above findings, the inventors conducted further studies and found that by ensuring that the arithmetic mean roughness Sa of the adhesive layer surface satisfies specific conditions, the occurrence of irregularities on the adhesive layer surface after peeling off the adhesive layer can be sufficiently suppressed, thus completing the present invention.

[0011] This disclosure includes the following aspects: [1] A semiconductor adhesive tape comprising a substrate, an adhesive layer disposed on the substrate, and an adhesive layer disposed on the adhesive layer, wherein the arithmetic mean roughness Sa of the surface of the adhesive layer furthest from the substrate is 0.012 μm or less. [2] The semiconductor adhesive tape according to [1], wherein the maximum height Sz of the surface of the adhesive layer furthest from the substrate is 0.380 μm or less. [3] A method for manufacturing a semiconductor adhesive tape comprising: preparing an adhesive tape comprising a substrate and an adhesive layer disposed on the substrate, wherein the arithmetic mean roughness Sa of the surface of the adhesive layer furthest from the substrate is 0.012 μm or less; and forming an adhesive layer on the adhesive layer. [4] The method for manufacturing a semiconductor adhesive tape according to [3], wherein the maximum height Sz of the surface of the adhesive layer furthest from the substrate is 0.380 μm or less. [5] The method for manufacturing a semiconductor adhesive tape according to [3] or [4], wherein the adhesive tape is obtained by peeling off the release film from a laminate comprising the substrate, an adhesive layer disposed on the substrate, and a release film disposed on the adhesive layer, and the arithmetic mean roughness Sa of the surface of the release film that is in contact with the adhesive layer is 0.012 μm or less. [6] The method for manufacturing a semiconductor chip with an adhesive layer, comprising: attaching the semiconductor adhesive tape according to [1] or [2] to a semiconductor wafer from the adhesive layer side; polishing the semiconductor wafer to which the adhesive tape is attached on the side opposite to the adhesive tape; and framing the polished semiconductor wafer to obtain a semiconductor chip with an adhesive layer. [7] A method for manufacturing a semiconductor device comprising a plurality of semiconductor chips stacked together, comprising: placing a first semiconductor chip with an adhesive layer obtained by the method described in [6] onto a substrate from the adhesive layer side, and pressing it together while heating to obtain a first laminate in which the substrate and the first semiconductor chip with an adhesive layer are stacked; and placing a second semiconductor chip with an adhesive layer obtained by the method described in [6] onto the first laminate from the adhesive layer side, and pressing it together while heating to obtain a second laminate in which the substrate, the first semiconductor chip with an adhesive layer and the second semiconductor chip with an adhesive layer are stacked together.

[0012] According to one aspect of this disclosure, it is possible to provide an adhesive film for semiconductors that is integrated with an adhesive tape, yet exhibits good flatness on the surface of the adhesive layer after the adhesive tape has been peeled off.

[0013] Figure 1 is a schematic cross-sectional view showing one embodiment of a semiconductor adhesive tape. Figure 2 is a schematic process cross-sectional view showing one embodiment of a semiconductor adhesive tape manufacturing method. Figure 3 is a schematic process cross-sectional view showing one embodiment of a semiconductor chip with an adhesive layer manufacturing method. Figure 4 is a schematic process cross-sectional view showing one embodiment of a semiconductor chip with an adhesive layer manufacturing method. Figure 5 is a schematic process cross-sectional view showing one embodiment of a semiconductor chip with an adhesive layer manufacturing method. Figure 6 is a schematic process cross-sectional view showing one embodiment of a semiconductor device manufacturing method. Figure 7 is a schematic process cross-sectional view showing one embodiment of a semiconductor device manufacturing method.

[0014] Hereinafter, one embodiment of the present invention will be described in detail, with reference to the drawings as appropriate. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and redundant explanations are omitted. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. In addition, the dimensional ratios in the drawings are not limited to those shown. In this specification, "(meth)acrylic" means at least one of acrylic and its corresponding methacrylic. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylate". Furthermore, numerical ranges indicated using "~" indicate a range that includes the numerical values ​​written before and after "~" as the minimum and maximum values, respectively. Furthermore, in numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with the values ​​shown in the examples. Furthermore, the upper and lower limits described individually can be combined arbitrarily. Furthermore, unless otherwise specified, the materials exemplified below may be used individually or in combination of two or more types. The content of each component in a composition refers to the total amount of any multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component are present in the composition.

[0015] [Semiconductor Adhesive Tape] Figure 1 is a schematic cross-sectional view showing one embodiment of the semiconductor adhesive tape of this disclosure. In this specification, "semiconductor adhesive tape" means that it is used in the manufacture of semiconductor devices, for example, to bond a semiconductor chip to a bonded member (a substrate such as a wiring circuit board or another semiconductor chip) and to seal the gap between the semiconductor chip and the substrate.

[0016] The semiconductor adhesive tape 10 (hereinafter simply referred to as "adhesive tape 10") comprises a support substrate 1, a film-like adhesive (adhesive layer) 2, and an adhesive tape 5. The adhesive tape 5 comprises an adhesive layer 3 and a substrate 4, and is attached to the film-like adhesive 2 from the adhesive layer 3 side. That is, the adhesive layer 3 forms the contact surface between the adhesive tape 5 and the film-like adhesive 2. The arithmetic mean roughness Sa of the surface of the adhesive layer 3 on the side furthest from the substrate 4 is 0.012 μm or less.

[0017] The adhesive tape 10 described above, while being an integrated adhesive tape, exhibits excellent flatness of the adhesive layer surface after the adhesive tape is peeled off. In contrast, when using conventional semiconductor adhesive tapes, the unevenness on the adhesive layer surface after the adhesive tape is peeled off can cause voids to form at the interface between the adherend (for example, another semiconductor chip or substrate when using a semiconductor chip with an adhesive layer) and the adhesive layer. Furthermore, the unevenness on the adhesive layer surface can affect the fluidity of the adhesive layer during mounting, potentially leading to a decrease in embedding performance. In contrast, as described above, the adhesive tape 10 according to this embodiment exhibits good flatness on the surface of the adhesive layer 2 exposed after the adhesive tape 5 is peeled off. Therefore, the formation of voids at the interface between the adherend and the adhesive layer can be sufficiently suppressed, and sufficient embedding performance can be obtained when embedding the adhesive layer 2 in narrow pitches.

[0018] The support substrate 1 is a substrate that supports the film-like adhesive 2 when manufacturing the film-like adhesive 2 or when attaching the adhesive tape 5 to the film-like adhesive 2. However, the support substrate 1 is not essential for the adhesive tape 10. For example, after attaching the adhesive tape 5 to the film-like adhesive 2, the support substrate 1 may be peeled off, and the adhesive tape 10 may be a laminate of substrate 4 / adhesive layer 3 / adhesive layer 2.

[0019] As the support substrate 1, for example, a polymer film having heat resistance and solvent resistance, such as polyethylene terephthalate, can be used. A commercially available example is polyethylene terephthalate film such as "A3100" manufactured by Toyobo Co., Ltd. The thickness of the support substrate 1 is preferably 10 to 100 μm, more preferably 30 to 75 μm, and particularly preferably 35 to 50 μm. If the thickness is less than 10 μm, the support substrate 1 tends to tear easily during coating, and if it exceeds 100 μm, it tends to be less cost-effective.

[0020] There are no particular restrictions on the composition of the film-like adhesive (adhesive layer) 2. Thermosetting or photocurable resins such as epoxy resin, acrylic resin, oxetane resin, and bismaleimide resin, thermoplastic resins such as phenoxy resin, polyethersulfone, polyamideimide, and polyimide, or sheets formed from a mixture of these resins can be used. Examples of the film-like adhesive 2 include NCF (Non-Conductive Film), high-heat-dissipating NCF, DAF (Die Attach Film), or C-DAF (Conductive Die Attach Film). Examples of embodiments in which the film-like adhesive 2 is NCF and embodiments in which the film-like adhesive 2 is high-heat-dissipating NCF will be described below.

[0021] (NCF) When the film-like adhesive 2 is NCF, the film-like adhesive 2 consists of an adhesive composition containing, for example, an epoxy resin and a curing agent. The adhesive composition may further contain, if necessary, high molecular weight components with a weight-average molecular weight of 10,000 or more, fluxes, fillers, etc.

[0022] Epoxy resins consist of compounds having two or more epoxy groups in their molecules. Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, triphenolmethane type epoxy resin, dicyclopentadiene type epoxy resin, and various polyfunctional epoxy resins.

[0023] Furthermore, the epoxy resin may include an epoxy resin that is liquid at 25°C. Using such an epoxy resin tends to suppress the occurrence of cracks and fissures on the film surface. Here, "liquid at 25°C" means that the viscosity at 25°C, as measured by an E-type viscometer, is 400 Pa·s or less. Examples of epoxy resins that are liquid at 25°C include bisphenol A type glycidyl ether, bisphenol AD ​​type glycidyl ether, bisphenol S type glycidyl ether, bisphenol F type glycidyl ether, water-added bisphenol A type glycidyl ether, ethylene oxide adduct bisphenol A type glycidyl ether, propylene oxide adduct bisphenol A type glycidyl ether, naphthalene resin glycidyl ether, trifunctional or tetrafunctional glycidylamine, etc.

[0024] The epoxy resin content may be 30% by mass or more, 35% by mass or more, 40% by mass or more, 42% by mass or more, or 45% by mass or more, based on the total amount of the film-like adhesive 2, from the viewpoint of suppressing fluctuations in the amount of fillet formation. The epoxy resin content may be 65% by mass or less, 60% by mass or less, 55% by mass or less, or 50% by mass or less, based on the total amount of the film-like adhesive, from the viewpoint of making it easier to obtain good sealing properties and making it easier to suppress the formation of voids.

[0025] Examples of curing agents include phenolic resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, imidazole-based curing agents, and phosphine-based curing agents. Among these, phenolic resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, and imidazole-based curing agents exhibit flux activity that suppresses the formation of oxide films at the connection site, and by using these curing agents, connection reliability can be improved.

[0026] The curing agent content may be 0.1 to 20 parts by mass, 0.1 to 10 parts by mass, or 0.1 to 5 parts by mass per 100 parts by mass of epoxy resin. When the curing agent content is 0.1 parts by mass or more per 100 parts by mass of epoxy resin, the curing properties tend to improve, and when it is 20 parts by mass or less, the film-like adhesive does not harden before the metal bond is formed, and connection failures tend to occur less easily.

[0027] High molecular weight components with a weight-average molecular weight of 10,000 or more (hereinafter simply referred to as "high molecular weight components") contribute to improved heat resistance and film formation. High molecular weight components are, for example, thermoplastic resins. Examples of high molecular weight components include phenoxy resins, polyimide resins, polyamide resins, polycarbodiimide resins, cyanate ester resins, acrylic resins, polyester resins, polyethylene resins, polyethersulfone resins, polyetherimide resins, polyvinyl acetal resins, urethane resins, and acrylic rubber. Among these, phenoxy resins, polyimide resins, acrylic rubbers, cyanate ester resins, and polycarbodiimide resins are preferred from the viewpoint of easily obtaining excellent heat resistance and film formation, and phenoxy resins, polyimide resins, and acrylic rubber are more preferred. These thermoplastic resins can be used individually or as mixtures or copolymers of two or more. Note that the epoxy resins mentioned above are not included in the high molecular weight components.

[0028] The weight-average molecular weight of the high molecular weight component may be 10,000 or more, 20,000 or more, or 30,000 or more, from the viewpoint of heat resistance and film-forming properties of the film-like adhesive 2. Alternatively, the weight-average molecular weight of the high molecular weight component may be 1,000,000 or less, or 500,000 or less, from the viewpoint of high heat resistance. In this specification, weight-average molecular weight refers to the value on a standard polystyrene basis, measured using GPC (Gel Permeation Chromatography).

[0029] When the film-like adhesive 2 contains a high molecular weight component, the content C of the high molecular weight component ｄ The epoxy resin content relative to C ａ ratio C ａ / C ｄ The (mass ratio) may be 0.01 to 5, 0.05 to 3, or 0.1 to 2. Ratio C ａ / C ｄ By setting the ratio to 0.01 or higher, better curability and adhesive strength can be obtained, and specific C ａ / C ｄ By setting the value to 5 or less, better film formation properties can be obtained.

[0030] Any known fluxing agent can be used without particular limitations, as long as it reduces and removes the oxide film on the surface of solder, etc., to facilitate metal joining. Specific examples of fluxing agents include dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, and dodecanediic acid, as well as compounds in which an electron-donating group is substituted at the 2-position of these dicarboxylic acids (e.g., 2-methylglutaric acid). Although some imidazole-based curing agents among the curing agents mentioned above have fluxing activity, compounds corresponding to imidazole-based curing agents are not considered fluxing agents.

[0031] The flux content may be 0.5 to 10% by mass, or 0.5 to 5% by mass, based on the total amount of the film-like adhesive 2.

[0032] Fillers are effective in controlling the viscosity of the film-like adhesive 2 and the physical properties of the cured product of the film-like adhesive 2. Insulating inorganic fillers, whiskers, and other inorganic fillers, as well as organic fillers such as resin fillers, can be used. One type of filler may be used alone, or two or more types may be used in combination. Since inorganic and organic fillers each have advantageous effects, either one may be used depending on the application, or both may be mixed to exhibit the functions of both.

[0033] Examples of insulating inorganic fillers include glass, silica, alumina, titanium oxide, carbon black, mica, and boron nitride. Among these, silica, alumina, titanium oxide, and boron nitride are preferred, and silica, alumina, and boron nitride are more preferred.

[0034] Examples of whiskers include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, and boron nitride.

[0035] Examples of resin fillers include those made of resins such as polyurethane and polyimide. Resin fillers contribute to improved connection reliability because they have a lower coefficient of thermal expansion compared to organic components (epoxy resins and curing agents, etc.). Resin fillers also allow for easy adjustment of the viscosity of the adhesive composition. Compared to inorganic fillers, resin fillers have superior stress-relieving properties, and therefore can further suppress delamination in reflow tests and other applications.

[0036] Among the above, insulating inorganic fillers are preferred from the viewpoint of insulation reliability (especially HAST resistance).

[0037] The shape, particle size, and content of the filler are not particularly limited. The filler may have its physical properties adjusted as appropriate by surface treatment.

[0038] The filler content may be, for example, 10 to 80% by mass or 15 to 60% by mass on a total basis of the adhesive composition.

[0039] (High Heat-Radiation Non-Conductive Film) When the film adhesive 2 is a high heat-radiation non-conductive film, the film adhesive 2 contains, for example, a thermosetting resin (hereinafter sometimes referred to as "component (A)"), a thermoplastic resin (hereinafter sometimes referred to as "component (C)"), and a thermally conductive filler (hereinafter sometimes referred to as "component (D)"). The film adhesive 2 may further contain a curing agent (hereinafter sometimes referred to as "component (B)"), a polymer having a main chain and a side chain bonded to the main chain, wherein at least one of the main chain and the side chain contains a polar group (hereinafter sometimes referred to as "component (E)"), a flux compound (hereinafter sometimes referred to as "component (F)"), an organic filler (hereinafter sometimes referred to as "component (G)"), and the like.

[0040] Component (A): Thermosetting resin Component (A) is a component that has the property of forming three-dimensional bonds between molecules and curing upon heating or the like, and exhibits an adhesive effect after curing. Component (A) may be an epoxy resin. Component (A) can be used without particular limitation as long as it has an epoxy group in the molecule. Component (A) may be a compound having two or more epoxy groups in the molecule.

[0041] Component (A) contains an epoxy resin that is solid at 25°C (hereinafter sometimes referred to as "component (A1)"). When component (A) contains component (A1), the minimum melt viscosity of the film adhesive tends to be further reduced. Here, "solid at 25°C" means that the viscosity at 25°C measured with an E-type viscometer is more than 400 Pa·s.

[0042] Examples of the component (A1) include bisphenol A epoxy resins, bisphenol F epoxy resins, naphthalene epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, phenol aralkyl epoxy resins, biphenyl epoxy resins, triphenylmethane epoxy resins, triphenolmethane epoxy resins, dicyclopentadiene epoxy resins, and various polyfunctional epoxy resins. From the viewpoint of suppressing fluctuations in the amount of fillet generated, the component (A1) may contain a triphenolmethane epoxy resin (a triphenolmethane skeleton-containing epoxy resin).

[0043] The epoxy equivalent of the component (A1) may be 50 to 500 g / eq, may be 100 to 400 g / eq, or may be 120 to 370 g / eq.

[0044] The component (A) may contain an epoxy resin that is liquid at 25°C (hereinafter sometimes referred to as "component (A2)"). When the component (A) contains the component (A2), it tends to be easy to suppress the occurrence of cracks and fissures on the film surface. Here, "liquid at 25°C" means that the viscosity measured at 25°C with an E-type viscometer is 400 Pa·s or less.

[0045] Examples of the component (A2) include glycidyl ethers of bisphenol A, glycidyl ethers of bisphenol AD, glycidyl ethers of bisphenol S, glycidyl ethers of bisphenol F, glycidyl ethers of hydrogenated bisphenol A, glycidyl ethers of ethylene oxide adduct bisphenol A, glycidyl ethers of propylene oxide adduct bisphenol A, glycidyl ethers of naphthalene resins, trifunctional or tetrafunctional glycidylamines, and the like.

[0046] The epoxy equivalent of the component (A2) may be 100 to 3000 g / eq, may be 100 to 2000 g / eq, or may be 100 to 1500 g / eq.

[0047] (A) The content of component (A) may be 5% by mass or more, 10% by mass or more, 15% by mass or more, 18% by mass or more, or 20% by mass or more, based on the total amount of the film adhesive, and may be 40% by mass or less, 35% by mass or less, 30% by mass or less, or 28% by mass or less, from the viewpoint of easily obtaining good sealing properties and easily suppressing the generation of voids.

[0048] (A1) The content of component (A1) may be 3% by mass or more, 5% by mass or more, 8% by mass or more, 10% by mass or more, or 12% by mass or more, based on the total amount of the film adhesive, and may be 30% by mass or less, 28% by mass or less, 26% by mass or less, 24% by mass or less, or 22% by mass or less, from the viewpoint of easily obtaining good sealing properties and easily suppressing the generation of voids.

[0049] The mass ratio of the content of component (A1) to the content of component (A) (content of component (A1) / content of component (A)) may be 0.50 or more, 0.55 or more, 0.60 or more, or 0.65 or more, and may be 1.00 or less, 0.95 or less, 0.90 or less, 0.85 or less, or 0.80 or less, from the viewpoint of making it easier to obtain good sealing properties and making it easier to suppress the generation of voids.

[0050] The mass ratio of the content of component (A2) to the content of component (A) (content of component (A2) / content of component (A)) may be 0 or more, 0.05 or more, 0.10 or more, 0.15 or more, or 0.20 or more, and may be 0.50 or less, 0.45 or less, 0.40 or less, or 0.35 or less.

[0051] (B) Component: Curing agent Examples of (B) component include phenol resin curing agents, acid anhydride curing agents, amine curing agents, imidazole curing agents, and phosphine curing agents. Among these, phenol resin curing agents, acid anhydride curing agents, amine curing agents, and imidazole curing agents exhibit flux activity that suppresses the formation of oxide films at the connection site, and by using these curing agents, connection reliability can be improved.

[0052] The phenolic resin curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in its molecule. Examples of phenolic resin curing agents include phenol novolac resins, cresol novolac resins, phenol aralkyl resins, cresol naphthol formaldehyde polycondensates, triphenylmethane-type polyfunctional phenolic resins, and various polyfunctional phenolic resins.

[0053] Examples of acid anhydride-based curing agents include methylcyclohexanetetracarboxylic acid dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic acid dianhydride, and ethylene glycol bisanhydrotrimellitate.

[0054] (B) Component (B) may contain at least one selected from the group consisting of phenolic resin curing agents, amine curing agents, imidazole curing agents, and phosphine curing agents, from the viewpoint of further improving storage stability and making it less susceptible to decomposition or deterioration due to moisture absorption, and may contain an imidazole curing agent.

[0055] The content of component (B) may be 0.1 to 20 parts by mass, 0.1 to 10 parts by mass, or 0.1 to 5 parts by mass per 100 parts by mass of component (A). When the content of the curing agent is 0.1 parts by mass or more per 100 parts by mass of component (A), the curability tends to improve, and when it is 20 parts by mass or less, the film-like adhesive does not harden before the metal bond is formed, and connection failures tend to occur less easily.

[0056] (C) Component: Thermoplastic resin Component (C) is a polymer that softens at high temperatures and contributes to improved heat resistance and film formation properties.

[0057] Examples of component (C) include phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, urethane resin, and acrylic rubber. Among these, component (C) may contain phenoxy resin, polyimide resin, acrylic rubber, cyanate ester resin, or polycarbodiimide resin, or it may contain phenoxy resin, polyimide resin, or acrylic rubber, from the viewpoint of easily obtaining excellent heat resistance and film formation properties.

[0058] The weight-average molecular weight of component (C) is, for example, 10,000 or more, and may be 20,000 or more or 30,000 or more. Such a thermoplastic resin can further improve the heat resistance and film-forming properties of the film-like adhesive. The weight-average molecular weight of component (C) may be 1,000,000 or less, and may be 500,000 or less, from the viewpoint of easily obtaining the effect of improving heat resistance. In this specification, weight-average molecular weight means the weight-average molecular weight measured in polystyrene equivalent using high-performance liquid chromatography (Shimadzu Corporation, product name: C-R4A). For example, the following conditions can be used for measurement. Detector: LV4000 UV Detector (manufactured by Hitachi, Ltd., product name) Pump: L6000 Pump (manufactured by Hitachi, Ltd., product name) Column: Gelpack GL-S300MDT-5 (2 in total) (manufactured by Resonac Corporation, product name) Eluent: THF / DMF = 1 / 1 (volume ratio) + LiBr (0.03 mol / L) + H3PO4 (0.06 mol / L) Flow rate: 1 mL / min

[0059] The glass transition temperature (Tg) of component (C) may be 120°C or lower, 100°C or lower, or 85°C or lower, from the viewpoint of excellent adhesion to connecting members (e.g., semiconductor chips) of the film-like adhesive. Here, Tg refers to the Tg measured using a DSC (e.g., PerkinElmer, product name: DSC-7) under the conditions of sample amount: 10 mg, heating rate: 10°C / min, and measurement atmosphere: air.

[0060] The content of component (C) may be 1% by mass or more, 3% by mass or more, 5% by mass or more, or 8% by mass or more, based on the total amount of the film-like adhesive. The content of component (C) may be 20% by mass or less, 18% by mass or less, or 15% by mass or less, based on the total amount of the film-like adhesive.

[0061] Component (D): Thermally conductive filler. Component (D) is a filler composed of a material that has thermal conductivity. When the film adhesive contains component (D), the cured product of the film adhesive has excellent heat dissipation properties. Component (D) may be surface-treated with a silane coupling agent or the like, or, from the viewpoint of reactivity with component (E), it may be an untreated filler that has not been surface-treated with a silane coupling agent or the like.

[0062] Component (D) may be a filler made of a substance having a thermal conductivity of 10 W / (m·K) or more at 20°C. The thermal conductivity at 20°C may be, for example, 2000 W / (m·K) or less, 1500 W / (m·K) or less, 1000 W / (m·K) or less, 500 W / (m·K) or less, or 200 W / (m·K) or less.

[0063] Component (D) may, in one embodiment, be a filler made of a substance having a thermal conductivity (at 20°C) of 10 to 200 W / (m·K). The thermal conductivity (at 20°C) may be, for example, 20 W / (m·K) or more, 30 W / (m·K) or more, 40 W / (m·K) or more, or 50 W / (m·K) or more, and may be 150 W / (m·K) or less, 120 W / (m·K) or less, 100 W / (m·K) or less, or 80 W / (m·K) or less.

[0064] Component (D) may, in one embodiment, be a filler composed of at least one substance selected from the group consisting of aluminum oxide, zinc oxide, magnesium oxide, boron nitride, aluminum nitride, silicon nitride, and silicon carbide, or it may be a filler composed of at least one substance selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, and aluminum nitride.

[0065] Component (D) may, in one embodiment, be a filler made of a metal, and may be a filler made of at least one substance selected from the group consisting of silver, copper, gold, aluminum, magnesium, tungsten, molybdenum, zinc, nickel, iron, platinum, tin, lead, and titanium, and may be silver or copper.

[0066] Component (D) may be, for example, a filler (alumina filler) made of aluminum oxide (alumina). The alumina filler may be made of alumina with a purity of 99.0% by mass or higher and low chlorine content, from the viewpoint of further improving thermal conductivity after heat curing and from the viewpoint of preventing electromigration when semiconductor devices are driven. Examples of commercially available fillers of this type include AA-3N, AA-07N, AA-03NF, and AA-04N (product names manufactured by Sumitomo Chemical Co., Ltd.). Component (D) may be a filler made of α-alumina with a purity of 99.0% by mass or higher.

[0067] The shape of component (D) is not particularly limited, but may be spherical, needle-shaped, plate-shaped, flaky, etc., or it may be polyhedron-shaped.

[0068] The average particle size of component (D) may be, for example, 0.01 to 5 μm. The average particle size of component (D) may be 3 μm or less, 2 μm or less, or 1 μm or less, and may be 0.1 μm or more, or 0.2 μm or more. The average particle size of component (D) is the particle size at the point corresponding to 50% of the volume when the cumulative frequency distribution curve by particle size is calculated with the total volume of the particles set to 100%, and can be measured using a particle size distribution analyzer using laser diffraction scattering or the like.

[0069] The content of component (D) is 50% by mass or more, based on the total amount of the film-like adhesive, from the viewpoint of forming a cured product with excellent heat dissipation properties. The content of component (D) may be 52% by mass or more, 55% by mass or more, or 57% by mass or more, based on the total amount of the film-like adhesive. The content of component (D) may be, for example, 90% by mass or less, 85% by mass or less, 80% by mass or less, 75% by mass or less, or 70% by mass or less, based on the total amount of the film-like adhesive.

[0070] Component (E): A polymer having a main chain and side chains bonded to the main chain, with at least one of the main chain and side chains containing a polar group. Component (E) is a component (dispersant) that contributes to improving the dispersibility of component (D). In other words, component (E) can also be described as a dispersant having a main chain and side chains bonded to the main chain, with at least one of the main chain and side chains containing a polar group. By containing component (E) in the film-like adhesive, it becomes possible to sufficiently reduce the viscosity when heated.

[0071] Here, "polymer" refers to high molecular weight components (compounds) with a weight-average molecular weight of 1000 or more. Note that the weight-average molecular weight is the weight-average molecular weight measured in polystyrene equivalent using high-performance liquid chromatography, as described above.

[0072] Component (E) has a main chain and side chains, and at least one of the main chain and side chain contains a polar group. The polar group can act as an adsorption site with component (D). Component (E) may also contain a polar group in its main chain.

[0073] The polar group may be, for example, an ionic group or a group derived from such ionic group. Specific examples of polar groups include acidic groups, acid ester groups, and acid anhydrides. The number of polar groups in one molecule of component (E) may be, for example, multiple (two or more).

[0074] Component (E) has side chains bonded to the main chain. The side chains can act as steric repulsion sites. The presence of side chains bonded to the main chain of component (E) can further improve the dispersibility of component (D). Examples of side chains include polyoxyalkylene chains, polyester chains, poly(meth)acrylate chains, polyurethane chains, and polyamide chains. From the viewpoint of solubility in solvents or resins, the side chains may be, for example, polyoxyalkylene chains. It is preferable that the side chains do not contain the above-mentioned polar groups. The number of side chains in one molecule of component (E) may be multiple (two or more).

[0075] In a film-like adhesive, component (E) may be adsorbed onto the surface of component (D). The adsorption site of component (E) may be, for example, a polar group. Adsorbing component (E) onto the surface of component (D) tends to further reduce the viscosity of the film-like adhesive when heated. A method for adsorbing component (E) onto the surface of component (D) is, for example, a method of mixing and kneading component (D) and component (E) in an organic solvent. The organic solvent used in this method may be the same as the organic solvent used in the preparation of the coating liquid described later. Mixing and kneading can be carried out using, for example, a stirrer, a three-roll mill, a ball mill, a bead mill, a homodisperser, etc.

[0076] The content of component (E) may be 0.1 parts by mass or more, 0.3 parts by mass or more, 0.5 parts by mass or more, or 0.7 parts by mass or more, and may be 12 parts by mass or less, 10 parts by mass or less, 8 parts by mass or less, or 6 parts by mass or less, per 100 parts by mass of component (D). When the content of component (E) is within this range, there is a tendency to further reduce the viscosity of the film-like adhesive when heated.

[0077] (F) Component: Flux compound Component (F) is a compound having flux activity. Component (F) can be any known compound without particular limitations, as long as it reduces and removes the oxide film on the surface of solder, etc., to facilitate metal bonding.

[0078] Component (F) may be a compound having a carboxyl group (carboxylic acid), or a polycarboxylic acid having two or more carboxyl groups, from the viewpoint of obtaining sufficient flux activity and superior connection reliability. The number of carboxyl groups in the polycarboxylic acid may be two. Polycarboxylic acids tend to be less volatile at high temperatures during connection compared to compounds having one carboxyl group (monocarboxylic acids). Therefore, polycarboxylic acids can further suppress the generation of voids. Among polycarboxylic acids, compounds having two carboxyl groups are superior to compounds having three or more carboxyl groups in terms of suppressing the increase in viscosity of the film adhesive during storage and connection work. Furthermore, when the film adhesive contains component (F), the interaction between component (F) and component (D) is suppressed due to the interaction between component (D) and component (E) and the steric hindrance caused by the side chain of component (E), which tends to further suppress the increase in viscosity.

[0079] The melting point of component (F) may be, for example, 150°C or lower, 140°C or lower, or 130°C or lower. Such component (F) tends to exhibit sufficient flux activity before the curing reaction between component (A) and component (B) occurs. Therefore, by using such a component (F), a semiconductor device with even better connection reliability can be obtained. Component (F) may be solid at room temperature (25°C). The melting point of the flux compound may be 25°C or higher, or 50°C or higher. In this specification, a melting point of 150°C or lower means that the upper limit of the melting point is 150°C or lower, and a melting point of 25°C or higher means that the lower limit of the melting point is 25°C or higher.

[0080] The content of component (F) may be 0.1% by mass or more, 0.5% by mass or more, or 1% by mass or more, based on the total amount of the film-like adhesive, from the viewpoint of obtaining a better flux effect. The content of component (F) may be 5% by mass or less, 3% by mass or less, or 2% by mass or less, based on the total amount of the film-like adhesive, from the viewpoint of reducing the amount of wafer warping when manufacturing semiconductor devices.

[0081] (G) Component: Organic filler. Examples of component (G) include resin fillers (resin particles). Examples of resin fillers include polyurethane and polyimide. Resin fillers can provide flexibility at high temperatures such as 260°C. Note that organic fillers composed of thermoplastic resins are not included in component (C).

[0082] The average particle size of component (G) may be, for example, 0.01 to 5 μm. The average particle size of component (G) may be 3 μm or less, 2 μm or less, or 1 μm or less, and may be 0.1 μm or more, or 0.2 μm or more. The average particle size of component (G) is the particle size at the point corresponding to 50% of the volume when the cumulative frequency distribution curve by particle size is calculated with the total volume of the particles set to 100%, and can be measured using a particle size distribution analyzer that uses laser diffraction scattering.

[0083] The content of component (G) may be, for example, 0.1% by mass or more, 0.5% by mass or more, 1% by mass or more, or 1.5% by mass or more, based on the total amount of the film-like adhesive, and may be 10% by mass or less, 7% by mass or less, 5% by mass or less, 4% by mass or less, or 3% by mass or less.

[0084] If the film-like adhesive 2 is a high-heat-dissipating NCF, the film-like adhesive may further contain other additives such as antioxidants, silane coupling agents, titanium coupling agents, leveling agents, and ion trapping agents. The content of these additives can be adjusted as appropriate so that the effects of each additive are realized.

[0085] In addition, while embodiments in which the film-like adhesive 2 is NCF and embodiments in which the film-like adhesive 2 is a high-heat-dissipating NCF have been described above, the film-like adhesive in this disclosure is not limited to these.

[0086] The thickness of the film-like adhesive 2 may be 2 to 50 μm or 5 to 20 μm. From the viewpoint of suppressing resin overflow after mounting, the thickness of the film-like adhesive 2 is preferably 5 to 16 μm. The thickness of the film-like adhesive 2 may be 0.6 to 1.5 times, 0.7 to 1.3 times, or 0.8 to 1.2 times the height of the electrode before connecting the semiconductor wafer. The thickness of the film-like adhesive 2 may also be less than the height of the electrode before connecting the semiconductor wafer. If the thickness of the film-like adhesive 2 is 0.6 times or more the height of the electrode (for example, the height T of the protruding electrode 26 shown in Figure 3(a)), the generation of voids due to incomplete filling of the adhesive can be sufficiently suppressed, and connection reliability can be further improved. If the thickness of the film-like adhesive 2 is 1.5 times or less, the amount of adhesive extruded from the chip connection area during connection can be sufficiently suppressed, so that the generation of fillets can be suppressed and the adhesion of adhesive to unnecessary parts can be sufficiently prevented.

[0087] The viscosity of the film-like adhesive 2 at 80°C may be 3,000 to 10,000 Pa·s, or 4,000 to 9,000 Pa·s. When the viscosity is within the above range, the resin melts easily during bonding and can flow sufficiently, making it less likely for voids to form around the electrodes and grooves, and furthermore, it is possible to ensure more reliable contact between opposing electrodes as a preliminary step to achieving a good connection. The viscosity of the film-like adhesive 2 is measured by the following procedure. First, a measurement sample with a thickness of 400 to 600 μm is prepared by bonding multiple film-like adhesives at a temperature of 60 to 80°C. The viscosity of this measurement sample is measured using ARES (manufactured by TA INSTRUMENTS, Inc., product name) under the following conditions: measurement jig diameter: 8 mm, measurement frequency: 10 Hz, measurement temperature range: 25°C to 260°C, heating rate: 10°C / min, and the viscosity at a predetermined temperature is determined. The viscosity of the film-like adhesive 2 can be adjusted, for example, by selecting high molecular weight components, selecting fillers, and adjusting their proportions.

[0088] The adhesive layer 3 has adhesive properties at room temperature and possesses the necessary adhesion to the adherend. Preferably, the adhesive layer 3 has the property of curing (reducing adhesive strength) when exposed to high-energy rays such as radiation or heat, but more preferably, it is easily peelable from the adhesive layer without the application of high-energy rays such as radiation or heat. The adhesive layer 3 may be a pressure-sensitive adhesive layer. The adhesive layer 3 can be formed using, for example, acrylic resin, various synthetic rubbers, natural rubber, or polyimide resin. Among these, when the adhesive layer 3 contains acrylic resin and / or methacrylic resin (hereinafter collectively referred to as "(meth)acrylic resin"), an effect of suppressing the increase in viscosity of the adhesive over time can be expected.

[0089] If the adhesive layer 3 has the property of hardening (reducing adhesive strength) when exposed to high-energy rays such as radiation, the adhesive layer 3 may contain, for example, an acrylic copolymer as the main component, a crosslinking agent, and a photopolymerization initiator. These components will be described below. In this specification, "main component" means a component whose content exceeds 50 parts by mass per 100 parts by mass of the composition constituting the target layer.

[0090] The above acrylic copolymer has at least one radiation-curable carbon-carbon double bond-containing group and one hydroxyl group in its main chain.

[0091] (Meth)acrylic resins, as acrylic copolymers, can contain unsaturated bonds in their side chains and possess adhesive properties. Such resins may have a glass transition temperature of -40°C or lower, a hydroxyl value of 20 to 150 mg KOH / g, contain 0.3 to 1.5 mmol / g of chain-polymerizable functional groups, have virtually undetectable acid values, and a weight-average molecular weight of 300,000 or more. (Meth)acrylic resins with these characteristics can be obtained by known synthesis methods, such as solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, precipitation polymerization, gas-phase polymerization, plasma polymerization, and supercritical polymerization. Polymerization reactions can include radical polymerization, cationic polymerization, anionic polymerization, living radical polymerization, living cationic polymerization, living anionic polymerization, coordination polymerization, immortal polymerization, and methods such as ATRP or RAFT. Among these methods, synthesis by radical polymerization using solution polymerization is preferred because it offers advantages such as cost-effectiveness, high reaction rate, ease of polymerization control, and the convenience of formulation, as the resin solution obtained by polymerization can be used directly in the formulation.

[0092] The monomer used in synthesizing the (meth)acrylic resin preferably contains at least one selected from (meth)acrylic esters, which are aliphatic esters having 8 to 23 carbon atoms. The (meth)acrylic resin obtained by copolymerizing such monomer components is preferable because it has a low glass transition temperature, exhibits excellent adhesive properties, and has strong hydrophobic interactions, resulting in excellent peelability at the interface between the adhesive layer 3 and the film-like adhesive 2 after irradiation with ultraviolet light or electron beams.

[0093] The polymerization initiator used in solution polymerization is not particularly limited as long as it is a compound that generates radicals when heated to 30°C or higher. Examples include ketone peroxides such as methyl ethyl ketone peroxide; peroxyketals such as 1,1-bis(t-butylperoxy)cyclohexane; hydroperoxides such as p-menthane hydroperoxide; dialkyl peroxides such as α,α'-bis(t-butylperoxy)diisopropylbenzene; diacyl peroxides such as octanoyl peroxide; peroxycarbonates such as bis(4-t-butylcyclohexyl)peroxydicarbonate; peroxyesters such as t-butylperoxypivalate; and 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azobis(4-methoxy-2'-dimethylvaleronitrile).

[0094] The reaction solvent used in solution polymerization is not particularly limited as long as it can dissolve (meth)acrylic resins, but examples include aromatic hydrocarbons such as toluene; cyclic ethers such as tetrahydrofuran; alcohols such as methanol; ketones such as acetone; esters such as methyl acetate; carbonate esters such as ethylene carbonate; polyhydric alcohol alkyl ethers such as ethylene glycol monomethyl ether; polyhydric alcohol alkyl ether acetates such as ethylene glycol monomethyl ether acetate; and amides such as N,N-dimethylformamide. Furthermore, these organic solvents can be used alone or in combination of two or more. Polymerization can also be carried out using supercritical carbon dioxide as a solvent.

[0095] Photosensitivity can be imparted to (meth)acrylic resins by chemically bonding functional groups that react to irradiation with ultraviolet light, electron beams, or visible light. Specific examples of functional groups that react to irradiation with ultraviolet light, electron beams, or visible light include (meth)acrylic groups, vinyl groups, allyl groups, glycidyl groups, alicyclic epoxy groups, and oxetane groups.

[0096] The crosslinking agent contained in the adhesive layer 3 is not particularly limited, and examples include at least one selected from hydroxyl groups, glycidyl groups, and amino groups introduced into a (meth)acrylic resin, and a compound having two or more functional groups in one molecule that can react with these functional groups. Examples of bonds formed by such a crosslinking agent include ester bonds, ether bonds, amide bonds, imide bonds, urethane bonds, and urea bonds. Among these, crosslinking agents having an aromatic group-containing isocyanate group are preferred because the peeling force between the adhesive layer 3 and the film-like adhesive 2 does not increase easily even when the amount of ultraviolet irradiation increases.

[0097] The crosslinking agent included in the adhesive layer 3 is preferably one having two or more isocyanate groups in one molecule. Using such a compound allows it to readily react with hydroxyl groups, glycidyl groups, amino groups, etc., introduced into the (meth)acrylic resin, forming a strong crosslinked structure and suppressing the adhesion of the adhesive layer 3 to the semiconductor chip after the die bonding process.

[0098] Specific examples of crosslinking agents having two or more isocyanate groups in one molecule include isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

[0099] Furthermore, oligomers containing isocyanate groups obtained by reacting the above-mentioned isocyanate compounds with polyhydric alcohols having two or more OH groups in one molecule can also be used. When obtaining such oligomers, examples of polyhydric alcohols having two or more OH groups in one molecule include ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, glycerin, pentaerythritol, dipentaerythritol, 1,4-cyclohexanediol, and 1,3-cyclohexanediol.

[0100] Among these, it is even more desirable that the crosslinking agent be a reaction product of a polyfunctional isocyanate having two or more isocyanate groups in one molecule and a polyhydric alcohol having three or more OH groups in one molecule. By using such an isocyanate group-containing oligomer, the adhesive layer 3 can form a dense crosslinked structure.

[0101] The amount of crosslinking agent contained in the adhesive layer 3 is preferably 10 to 13 parts by mass per 100 parts by mass of the acrylic copolymer. If the amount of crosslinking agent is less than 10 parts by mass, the elongation at break of the adhesive layer 3 before UV irradiation will be high, and the machinability during the dicing process will likely be insufficient. In addition, the peeling force between the adhesive layer 3 and the film-like adhesive 2 after UV irradiation will not decrease sufficiently, and it will likely be necessary to set a relatively large push-up amount during the pickup process. On the other hand, if the amount of crosslinking agent exceeds 13 parts by mass, the adhesive force with the adhesive layer 3 before UV irradiation will likely be insufficient.

[0102] The photopolymerization initiator contained in the adhesive layer 3 is not particularly limited as long as it generates active species capable of causing chain polymerization of the acrylic copolymer upon irradiation with one or more types of light selected from ultraviolet light, electron beams, and visible light. For example, it may be a photoradical polymerization initiator or a photocationic polymerization initiator. The chain polymerization-capable active species is not particularly limited as long as it initiates the polymerization reaction by reacting with the functional groups of the acrylic copolymer.

[0103] Examples of photoradical polymerization initiators include benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-hydroxyketones such as 1-hydroxycyclohexylphenyl ketone; α-aminoketones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one; oxime esters such as 1-[4-(phenylthio)phenyl]-1,2-octadione-2-(benzoyl)oxime; phosphine oxides such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; 2- Examples include 2,4,5-triarylimidazole dimers such as (o-chlorophenyl)-4,5-diphenylimidazole dimer; benzophenone compounds such as benzophenone and N,N,N',N'-tetramethyl-4,4'-diaminobenzophenone; quinone compounds such as 2-ethylanthraquinone; benzoin ethers such as benzoin methyl ether; benzoin compounds such as benzoin and methylbenzoin; benzyl compounds such as benzyldimethylketal; acridine compounds such as 9-phenylacridine; N-phenylglycine, coumarin, etc.

[0104] Examples of photocationic polymerization initiators include aryldiazonium salts such as p-methoxybenzenediazonium hexafluorophosphate; diaryliodonium salts such as diphenyliodonium hexafluorophosphate; triarylsulfonium salts such as triphenylsulfonium hexafluorophosphate; triarylselenonium salts such as triphenylselenonium hexafluorophosphate; dialkylphenacylsulfonium salts such as dimethylphenacylsulfonium hexafluoroantimonate; dialkyl-4-hydroxy salts such as 4-hydroxyphenyldimethylsulfonium hexafluoroantimonate; and sulfonic acid esters such as α-hydroxymethylbenzoin sulfonic acid ester. These cationic polymerization initiators can be used alone or in combination of two or more types. Furthermore, they can also be used in combination with an appropriate sensitizer.

[0105] When a high level of insulating properties and insulating reliability is required for the adhesive layer 3, it is preferable to use a photoradical initiator, among which benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one; α-hydroxy phenyl ketones such as 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one are preferred. Ketones, benzophenones, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthaquinone, 2-methyl-1,4-naphthoquinone, 2,3- Quinone compounds such as dimethylanthraquinone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; benzyl compounds such as benzyldimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinylheptane); N-phenylglycine and coumarin are preferred due to their excellent storage stability, and 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one and benzophenone are even more preferred because they can be handled under general UV-blocking fluorescent lamps and do not require facilities such as a yellow room.

[0106] The optimal amount of photopolymerization initiator varies depending on the desired thickness of the adhesive layer 3 and the light source used, but it is preferably 0.5 to 1.5 parts by mass per 100 parts by mass of acrylic copolymer. If the amount of photopolymerization initiator is 0.5 parts by mass or more, the peeling force with the film-like adhesive 2 after UV irradiation can be sufficiently reduced. If the amount of photopolymerization initiator is 1.5 parts by mass or less, the decomposition of the adhesive layer 3 when irradiated with UV light can be suppressed.

[0107] The arithmetic mean roughness Sa of the surface of the adhesive layer 3 furthest from the substrate 4 (the surface in contact with the adhesive layer 2) is 0.012 μm or less, preferably 0.011 μm or less, and more preferably 0.010 μm or less. By having a surface Sa of 0.012 μm or less, good flatness can be obtained on the surface of the adhesive layer 2 after peeling off the adhesive tape 5. In this specification, "arithmetic mean roughness Sa" is the average value of the height difference from the average surface on a reference surface.

[0108] The maximum height Sz of the surface of the adhesive layer 3 furthest from the substrate 4 is preferably 0.380 μm or less, more preferably 0.350 μm or less, and even more preferably 0.320 μm or less, from the viewpoint of the flatness of the surface of the adhesive layer 2 after peeling off the adhesive tape 5. In this specification, "maximum height Sz" represents the sum of the maximum peak height and the maximum valley depth of the contour curve on the reference surface.

[0109] The thickness of the adhesive layer 3 is preferably 0.5 to 295 μm, more preferably 1 to 150 μm, and even more preferably 2 to 100 μm. When this thickness is 0.5 μm or more, it becomes easier to suppress the generation of voids during lamination of the film-like adhesive 2, and in particular, it tends to suppress void entrapment even when the difference between the height of the electrode and the thickness of the film-like adhesive 2 is large. On the other hand, when this thickness is 295 μm or less, it is possible to suppress an increase in the amount of residual solvent in the adhesive layer 3, and it tends to suppress the occurrence of variations in adhesive strength due to the influence of residual solvent.

[0110] The thickness of the adhesive layer 3 may be three times or more the thickness of the film-like adhesive 2. However, if the thickness of the adhesive layer 3 is increased too much, the thickness variation will increase and the cost of raw materials will increase, so it is more preferable that the thickness of the adhesive layer 3 be three to five times the thickness of the film-like adhesive 2.

[0111] The base material 4 can be a known polymer sheet or film, and is not particularly limited. Specific examples of the base material 4 include polyolefins such as crystalline polypropylene, amorphous polypropylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, low-density linear polyethylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, polyurethane, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycarbonate, polyimide, polyetheretherketone, polyimide, polyetherimide, polyamide, fully aromatic polyamide, polyphenyl sulfide, aramid (paper), glass, glass cloth, fluororesin, polyvinyl chloride, polyvinylidene chloride, cellulose resin, silicone resin, or mixtures of these mixed with a plasticizer, or cured products obtained by crosslinking by electron beam irradiation. The base material 4 may have a surface mainly composed of at least one of the resins described in the above specific examples, and this surface may be in contact with the adhesive layer 3. These resins can be good base materials from the viewpoint of properties such as Young's modulus, stress relaxation properties, and heat resistance, as well as from the viewpoint of cost and recycling of waste materials after use. The base material 4 may be a single layer, or it may have a multilayer structure in which layers made of different materials are laminated as needed. From the viewpoint of controlling adhesion with the adhesive layer 3, the surface of the base material 4 may be subjected to surface roughening treatment such as mat treatment or corona treatment. The base material 4 can be a single layer or a laminate, and if it is a laminated structure, it is fine to have the same resin composition, or to have a resin composition in which other resins are mixed in each layer, and as a layer structure, a base material film with two or three layers is also fine.

[0112] The thickness of the substrate 4 is preferably 5 to 200 μm, and more preferably 12 to 150 μm. When the thickness is 5 μm or more, it is easier to suppress deformation of the substrate 4 due to thermal shrinkage during the drying process of the adhesive layer 3, and it is easier to suppress variations in the thickness of the adhesive layer 3. Furthermore, when the adhesive tape 5 is a back-grind tape, when the thickness of the substrate 4 is 200 μm or less, it is easier to more effectively suppress the warping of the wafer after back-grinding.

[0113] As long as the Sa on the surface of the adhesive layer 3 furthest from the substrate 4 satisfies the above conditions, the adhesive tape 5 comprising the adhesive layer 3 and the substrate 4 can be a backgrind tape, a dicing tape, a protective tape (for example, a film that is peeled off after lamination of the film-like adhesive 2 to the adherend), etc. Furthermore, regarding the combination of the adhesive tape 5 and the film-like adhesive 2, the adhesive tape 10 includes the following embodiments: (A) An adhesive tape 10 in which the adhesive tape 5 is a backgrind tape and the film-like adhesive 2 is NCF or high heat dissipation NCF. (B) An adhesive tape 10 in which the adhesive tape 5 is a protective tape and the film-like adhesive 2 is NCF or high heat dissipation NCF. (C) An adhesive tape 10 in which the adhesive tape is a dicing tape and the film-like adhesive 2 is DAF or C-DAF.

[0114] [Method for Manufacturing Adhesive Tape for Semiconductors] Figure 2 is a cross-sectional view illustrating a method for manufacturing adhesive tape for semiconductors according to one embodiment of the present disclosure.

[0115] A method for manufacturing a semiconductor adhesive tape 10 comprises the steps of: preparing an adhesive tape 5 comprising a base material 4 and an adhesive layer 3 disposed on the base material 4, wherein the arithmetic mean roughness Sa of the surface of the adhesive layer 3 on the side furthest from the base material 4 is 0.012 μm or less (adhesive tape preparation step, Figure 2(a)); and forming an adhesive layer 2 on the adhesive layer 3 (adhesive layer formation step, Figures 2(b) and (c)).

[0116] The adhesive tape 5 can be formed, for example, by dissolving or dispersing an adhesive composition containing the components of the adhesive layer 3 in a solvent to form a varnish, applying this varnish to the substrate 4, and removing the solvent by heating.

[0117] The solvent used in preparing the above varnish is not particularly limited, but it is preferable to determine it by considering its volatility when forming the adhesive layer 3, based on its boiling point. Specifically, relatively low-boiling point solvents such as methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, toluene, and xylene can be used. Relatively high-boiling point solvents such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, and cyclohexanone may be used to improve coating properties. These solvents can be used individually or in combination of two or more.

[0118] Methods for applying the above-mentioned varnish onto the substrate 4 include generally known methods such as knife coating, roll coating, spray coating, gravure coating, bar coating, curtain coating, comma coating, and die coating.

[0119] The preferred temperature for removing the solvent by heating is around 70 to 150°C.

[0120] In the adhesive tape preparation process, the surface of the adhesive layer 3 furthest from the substrate 4 may be covered with a release film (separator) 11 to protect it. The release film 11 is peeled off the adhesive tape 5 before it is subjected to the adhesive layer formation process.

[0121] Examples of materials for the release film 11 include polyethylene terephthalate, polypropylene, and polyethylene. The thickness of the release film 11 may be, for example, 5 to 100 μm, 10 to 70 μm, or 15 to 50 μm. The surface of the release film 11 may be treated with a release agent.

[0122] The adhesive tape 5 can also be formed by dissolving or dispersing an adhesive composition containing the components of the adhesive layer 3 in a solvent to form a varnish, applying this varnish onto the release film 11, removing the solvent by heating to form the adhesive layer 3, and then laminating the substrate 4 to the side of the adhesive layer 3 furthest from the release film 11.

[0123] The arithmetic mean roughness Sa of the surface of the release film 11 that is in contact with the adhesive layer 3 is preferably 0.012 μm or less, more preferably 0.011 μm or less, and even more preferably 0.010 μm or less. When the Sa of the surface is 0.012 μm or less, good flatness can be imparted to the surface of the adhesive layer 3 that is farther from the substrate 4.

[0124] The maximum height Sz of the surface of the release film 11 that is in contact with the adhesive layer 3 is preferably 0.550 μm or less, more preferably 0.500 μm or less, and even more preferably 0.450 μm or less. When the Sz of the surface is 0.550 μm or less, good flatness can be provided to the surface of the adhesive layer 3 that is farther from the substrate 4.

[0125] Next, in the adhesive layer formation step, an adhesive layer (film-like adhesive) 2 is formed on the adhesive layer 3 of the adhesive tape 5, and the adhesive tape 10 is obtained (Figures 2(b) and (c)).

[0126] One method for forming the adhesive layer 2 on the adhesive layer 3 is to bond a laminate (film-like adhesive with support substrate) comprising a support substrate 1 and a film-like adhesive 2 to the adhesive layer 3 of the adhesive tape 5.

[0127] A film-like adhesive with a support substrate can be obtained, for example, by dissolving or dispersing an adhesive composition containing the components of the adhesive layer 2 in a solvent to prepare a varnish, applying the varnish onto the support substrate 1, and removing the solvent by heating. The solvent used to prepare the varnish, the method of applying the varnish, and the temperature conditions for removing the solvent are exemplified to be the same as those used when forming the adhesive layer 3.

[0128] Methods for bonding the film-like adhesive with a support substrate to the adhesive layer 3 of the adhesive tape 5 include heat pressing, roll lamination, and vacuum lamination. The temperature conditions during bonding may be, for example, 20 to 80°C. The pressure conditions may be, for example, 0.01 to 10.0 MPa.

[0129] Alternatively, the adhesive can be prepared by dissolving or dispersing an adhesive composition containing the components of the adhesive layer 2 in a solvent, applying the varnish onto the adhesive layer 3 of the adhesive tape 5, and removing the solvent by heating. The solvent used for preparing the varnish, the method of applying the varnish, and the temperature conditions for removing the solvent are exemplified to be the same as those used when forming the adhesive layer 3.

[0130] According to the above manufacturing method, the arithmetic mean roughness Sa of the surface of the adhesive layer 3 furthest from the substrate 4 (the surface in contact with the adhesive layer 2) is 0.012 μm or less, making it possible to obtain an adhesive tape 10 that can impart good flatness to the surface of the adhesive layer 2 after peeling off the adhesive layer 3. The adhesive tape 10 is useful in the manufacture of semiconductor chips and semiconductor devices with adhesive layers, as described later.

[0131] <Method for manufacturing semiconductor chips and semiconductor devices with adhesive layer> Next, a method for manufacturing semiconductor chips and semiconductor devices with an adhesive layer using the adhesive tape 10 of the above embodiment will be described.

[0132] Figures 3 to 5 are schematic cross-sectional views illustrating a method for manufacturing a semiconductor chip 30 with an adhesive layer according to one embodiment.

[0133] The method for manufacturing a semiconductor chip 30 with an adhesive layer comprises a lamination step (Figure 3) in which an adhesive tape 10 is attached to a semiconductor wafer 20 from the film-like adhesive 2 side, a backgrinding step (Figure 4) in which the side of the semiconductor wafer 20 to which the adhesive tape 10 is attached that is polished on the side opposite to the adhesive tape 10, and a dicing step (Figure 5) after the backgrinding step in which the semiconductor wafer 20 is divided into individual pieces to obtain a semiconductor chip 30 with an adhesive layer. In this embodiment, the adhesive tape 5 of the adhesive tape 10 is a backgrinding tape, so a backgrinding step is included, but the backgrinding step is not essential. If the backgrinding step is not performed, the adhesive tape 5 may be, for example, a dicing tape, a protective tape, etc. That is, the method for manufacturing a semiconductor chip with an adhesive layer may also comprise a lamination step in which an adhesive tape is attached to a semiconductor wafer from the film-like adhesive side, and a dicing step after the lamination step in which the semiconductor wafer is divided into individual pieces to obtain a semiconductor chip with an adhesive layer.

[0134] The semiconductor wafer 20 used in this embodiment is provided with a protruding electrode (solder bump) 26 on one of its main surfaces (Figure 3(a)). The protruding electrode 26 consists of a bump 22 and a solder ball 24 provided on the bump 22.

[0135] Examples of semiconductor wafers 20 include 6-inch wafers, 8-inch wafers, and 12-inch wafers whose surfaces are treated with an oxide film. Examples of bumps 22 include those made of copper, silver, gold, etc. Examples of solder balls 24 include those made of conventionally known solder materials such as lead-containing solder or lead-free solder.

[0136] On the main surface of the semiconductor wafer 20, where the protruding electrodes 26 are provided, grooves 28 are formed to serve as scribe lines that act as markers during dicing. The grooves 28 consist of recesses with a depth of approximately 5 to 15 μm.

[0137] The thickness of the semiconductor wafer 20 before thinning can be in the range of 250 to 800 μm. Typically, the cut semiconductor wafer has a thickness of 625 to 775 μm for a size of 6 to 12 inches.

[0138] In Figure 3(a), the height T of the protruding electrode is the sum of the height of the bump 22 and the height of the solder ball 24. From the viewpoint of semiconductor miniaturization, the height of the bump 22 is preferably 5 to 50 μm. From the viewpoint of semiconductor miniaturization, the height of the solder ball 24 is preferably 2 to 30 μm.

[0139] In the lamination process, the support substrate 1 is peeled off from the adhesive tape 10, and the film-like adhesive (adhesive layer) 2, adhesive layer 3, and substrate 4 are arranged in this order on the surface of the semiconductor wafer 20 on which the protruding electrodes (solder bumps) 26 are formed (hereinafter referred to as the "functional surface"), and pressure is applied to the semiconductor wafer 20 and substrate 4 so that the tip of the solder ball 24 penetrates the film-like adhesive 2 (see Figure 3(b)). It is most desirable for the tip of the solder ball to penetrate the adhesive layer, but even if a few microns of adhesive layer remain on the tip of the solder ball, it is not a problem as long as it does not affect the connectivity when the substrate and semiconductor chip are electrically connected via the solder ball, as described later. In this embodiment, the protrusion of the bumps is made easier by bonding the film-like adhesive 2 to the functional surface of the semiconductor wafer 20 by vacuum lamination.

[0140] Vacuum lamination methods include diaphragm-based, roll-based, and press-based methods, but the diaphragm-based method is preferred from the standpoint of ease of embedding.

[0141] The preferred lamination conditions are: lamination temperature: 50°C to 100°C, linear pressure: 0.5 to 3.0 kgf / cm, and feed speed: 0.2 to 2.0 m / min.

[0142] When using the diaphragm method for vacuum lamination, the following conditions are preferable: stage temperature: 20°C to 60°C, diaphragm temperature: 50°C to 100°C, degassing time: 10 to 100 seconds, pressurization time: 10 to 100 seconds, and pressurization: 0.1 to 1.0 MPa. In the case of the diaphragm method, the lamination temperature refers to the diaphragm temperature.

[0143] Performing lamination at temperatures exceeding 80°C tends to increase wafer warping after backgrinding. On the other hand, if the lamination temperature is too low, it tends to become difficult to fill in the areas around the bumps. Therefore, it is preferable to perform lamination at 50-80°C.

[0144] In the backgrinding process, the semiconductor wafer 20 to which the adhesive tape 10 is attached is polished on the side opposite to the adhesive tape 10, that is, the side opposite to the side where the protruding electrodes (solder bumps) 26 of the semiconductor wafer 20 are formed, thereby thinning the semiconductor wafer 20 (Figure 4). Polishing can be performed using a back grinder.

[0145] In the backgrinding process, it is preferable to thin the semiconductor wafer 20 to a thickness of 10 to 150 μm. If the thickness of the thinned semiconductor wafer 20 is less than 10 μm, the semiconductor wafer is prone to damage, while if it exceeds 150 μm, it becomes difficult to meet the demand for miniaturization of semiconductor devices.

[0146] In the dicing process, first, the polished side of the thinned semiconductor wafer 20 is attached to the dicing tape 6 (Figure 5(a)). Next, using a dicing apparatus, the semiconductor wafer 20 and the film-like adhesive 2 are cut along the groove 28 to separate the semiconductor wafer 20 into individual pieces (Figure 5(b)). This yields an adhesive-layered semiconductor chip 30 consisting of a semiconductor chip 29 and an adhesive layer 9. The adhesive tape 5, consisting of a base material 4 and an adhesive layer 3, may be peeled off from the film-like adhesive 2 before dicing.

[0147] After the dicing process is complete, the adhesive-backed semiconductor chips are picked up using a pickup device and used in the manufacture of semiconductor devices.

[0148] Although not shown in the figures, the manufacturing method of this embodiment may include a step of forming electrodes on the main surface of the semiconductor wafer 20 or semiconductor chip 29 opposite to the main surface on which the protruding electrodes 26 are formed, from the viewpoint of obtaining a semiconductor chip with an adhesive layer applicable to stacking and multi-stage technology, and may also include a step of forming through electrodes on the semiconductor wafer 20 or semiconductor chip 29. The method for manufacturing the electrodes is not particularly limited, and known methods may be employed.

[0149] Figures 6 and 7 are schematic cross-sectional views illustrating the manufacturing method of the semiconductor device 100 according to this embodiment.

[0150] The method for manufacturing the semiconductor device 100 comprises a first lamination step (Figure 6) in which a first adhesive layer-equipped semiconductor chip 30a is placed on a substrate 7 from the adhesive layer 9a side and pressed together while heating, and a second lamination step (Figure 7) in which a second adhesive layer-equipped semiconductor chip 30b is placed on a laminate 40 obtained in the first lamination step from the adhesive layer 9b side and pressed together while heating. The first adhesive layer-equipped semiconductor chip 30a and the second adhesive layer-equipped semiconductor chip 30b are adhesive layer-equipped semiconductor chips obtained by the method of the above embodiment. The first adhesive layer-equipped semiconductor chip 30a and the second adhesive layer-equipped semiconductor chip 30b have electrodes (31a, 31b) on the side opposite to the side on which the protruding electrodes (26a, 26b) are provided, and through electrodes (32a, 32b) are formed between the electrodes (31a, 31b) and the protruding electrodes (26a, 26b). The substrate 7 is another semiconductor chip having electrodes 8 or a support member for mounting a semiconductor chip having electrodes (such as a wiring circuit board).

[0151] In the first lamination process, the semiconductor chip 30a with the first adhesive layer is heated and pressurized in a direction in which the protruding electrode 26a and the electrode 8 face each other, thereby melting the solder on the protruding electrode 26a and joining the protruding electrode 26a of the first semiconductor chip 30a with the adhesive layer to the electrode 8 of the substrate 7 (Figures 6(a) and 6(b)).

[0152] The first lamination step may include a first thermocompression bonding step in which the semiconductor chip 30a with an adhesive layer and the substrate 7 are pressed together at a temperature lower than the melting point of the solder on the protruding electrode 26a in a direction in which the protruding electrode 26a and the electrode 8 face each other, and a second thermocompression bonding step in which the solder on the protruding electrode 26a is melted by heating to join the protruding electrode 26a and the electrode 8.

[0153] If the adhesive layer 9a further contains a flux component, the pressurization in the first thermocompression bonding step may be performed at a temperature higher than the melting or softening point of the flux component and lower than the melting point of the solder on the protruding electrode. In this case, a stronger connection can be obtained.

[0154] The conditions for the first heat-sealing process are preferably 100°C to 200°C, pressure 0.1 MPa to 1.5 MPa, and time 1 to 15 seconds, and more preferably 100°C to 180°C, pressure 0.1 MPa to 1.0 MPa, and time 1 to 10 seconds. The conditions for the second heat-sealing process are preferably 230°C to 350°C, pressure 0.1 MPa to 1.5 MPa, and time 1 to 15 seconds, and more preferably 230°C to 300°C, pressure 0.1 MPa to 1.0 MPa, and time 1 to 15 seconds. The above temperature and pressure conditions refer to the temperature and pressure applied to the adhesive layer.

[0155] In this way, the electrodes 8 of the substrate 7 and the bumps 22a of the semiconductor chip 29a are electrically connected via solder balls 24a, and the space between the substrate 7 and the semiconductor chip 29a is sealed by the sealing portion 35a, which is a cured adhesive, to obtain a laminate 40 (Figure 6(b)).

[0156] In the second lamination process, the semiconductor chip 30b with the second adhesive layer is heated and pressurized in a direction in which the protruding electrodes (solder bumps) 26b and the electrode 31a face each other, thereby melting the solder on the protruding electrodes 26b and joining the protruding electrodes 26b of the semiconductor chip 30b with the second adhesive layer to the electrode 31a of the laminate 40 (Figures 7(a) and 7(b)).

[0157] The second lamination process can be carried out in the same manner as the first lamination process. The details of the heating and pressing conditions in the second lamination process are the same as the details of the heating and pressing conditions in the first lamination process.

[0158] In this way, the electrodes 31a of the laminate 40 and the bumps 22b of the semiconductor chip 29b are electrically connected via solder balls 24b, and the space between the laminate 40 and the semiconductor chip 29b is sealed by the sealing portion 35b, which is a cured adhesive, thereby obtaining the semiconductor device 100 (Figure 7(b)).

[0159] In this embodiment, multiple semiconductor chips with adhesive layers may be stacked in multiple stages by repeating a process similar to the second stacking step. That is, the manufacturing method of this embodiment may include multiple steps of further stacking semiconductor chips with adhesive layers on the semiconductor device 100.

[0160] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

[0161] The present invention will be described more specifically below with reference to examples. However, the present invention is not limited to these examples.

[0162] [Measurement Method for Arithmetic Mean Roughness Sa and Maximum Height Sz] The measurement methods for the arithmetic mean roughness Sa and maximum height Sz in the following examples and comparative examples are as follows. A sample with a sample size of 100 mm x 340 mm is cut out, and five equally spaced points are measured using a nano 3D optical interference measurement system (VS1800 manufactured by Hitachi High-Tech Corporation) in the following manner, and the average value is used. (1) Place glass ("Tempax" (registered trademark), borosilicate glass, 200 mm x 200 mm x 5 mm thick) on the stage. (2) Set the cut-out sample on the glass with the surface to be measured facing upwards, and leave it for about 10 minutes until the distortion and waviness of the film subside. (3) Set a predetermined lens magnification and observe the film surface at an observation magnification of 50x. (4) Take a picture with the focus set to the outermost surface of the sample under the following conditions.・Lamp: Light intensity optimized using an auto lamp ・Measurement device: Motor ・Measurement mode: Wave ・Field of view size (pixels): 1024 x 1024 ・Scan range: Start 10 μm, Stop -10 μm ・Effective pixels (%): 5 ・Average count: 2 (5) The analysis will be performed as follows: ・Analysis using ISO parameters ・S-filter: Automatic ・Normal probability paper: 300 divisions ・Calculation range: Upper limit 3.0, lower limit -3.0 ・Surface correction: Yes (Approximate surface shape correction: 4th order) ・Interpolation: Yes (Perfect interpolation) (6) Record the calculated Sa and Sz.

[0163] [Adhesive Tape] The following backgrind tapes were prepared as adhesive tapes (adhesive tapes with release film). Base material: Polyolefin film, thickness: 100 μm Adhesive layer: Adhesive layer containing (meth)acrylic resin, thickness: 10 μm Release film: Polyethylene terephthalate film, thickness: 25 μm, arithmetic mean roughness Sa: 0.004 μm, maximum height Sz: 0.217 μm (BGT-2) Base material: Polyolefin film, thickness: 100 μm Adhesive layer: Adhesive layer containing (meth)acrylic resin, thickness: 10 μm Release film: Polyethylene terephthalate film, thickness: 25 μm, arithmetic mean roughness Sa: 0.003 μm, maximum height Sz: 0.367 μm (BGT-3) Base material: Polyethylene terephthalate film, thickness: 25 μm Adhesive layer: Adhesive layer containing (meth)acrylic resin, thickness: 30 μm Release film: Polyethylene terephthalate film, thickness: 25 μm, arithmetic mean roughness Sa: 0.004 μm, maximum height Sz: 0.197 μm (BGT-4) Substrate: Polyethylene terephthalate film, thickness: 25 μm Adhesive layer: Adhesive layer containing (meth)acrylic resin, thickness: 30 μm Release film: Polyethylene terephthalate film, thickness: 25 μm, arithmetic mean roughness Sa: 0.003 μm, maximum height Sz: 0.376 μm (BGT-5) Substrate: Polyolefin film, thickness: 100 μm Adhesive layer: Adhesive layer containing (meth)acrylic resin, thickness: 10 μm Release film: Polyethylene terephthalate film, thickness: 25 μm, arithmetic mean roughness Sa: 0.016 μm, maximum height Sz: 0.939 μm (BGT-6) Substrate: Polyethylene terephthalate film, thickness: 25 μm; Adhesive layer: Adhesive layer containing (meth)acrylic resin, thickness: 30 μm; Release film: Polyethylene terephthalate film, thickness: 25 μm, arithmetic mean roughness Sa: 0.022 μm, maximum height Sz: 1.857 μm.

[0164] [Film-type adhesives] The following NCFs were prepared as film-type adhesives (film-type adhesives with a support substrate). (NCF-1) Support substrate: polyethylene terephthalate, thickness: 38 μm Adhesive layer: adhesive layer containing phenolic resin, epoxy resin, curing agent, and silica filler, thickness: 6.0 μm (NCF-2) Support substrate: polyethylene terephthalate, thickness: 38 μm Adhesive layer: adhesive layer containing phenolic resin, epoxy resin, curing agent, and silica filler, thickness: 10.0 μm.

[0165] [Examples 1-4, Comparative Examples 1-2] In Examples 1-4 and Comparative Examples 1-2, adhesive tapes and film-like adhesives were combined as shown in Table 1 to produce adhesive films with adhesive tapes. Specifically, after peeling the release film from the adhesive tape, the adhesive tape and the adhesive tape with a support substrate were laminated using a roll laminator (lamination temperature: 25°C) to obtain an adhesive tape having a laminated structure of substrate / adhesive layer / adhesive layer / support substrate. After peeling the release film, the arithmetic mean roughness Sa and maximum height Sz of the adhesive layer surface, measured for the adhesive tape used for lamination with the film-like adhesive, are shown in Table 1.

[0166] [Evaluation of the flatness of the adhesive layer surface after peeling off the adhesive tape] For the adhesive tapes of Examples 1 to 4 and Comparative Examples 1 to 2, the flatness of the adhesive layer surface after peeling off the adhesive tape was evaluated. The specific procedure is as follows: (1) A sample with a size of 380 mm x 380 mm is cut out, and an observation sample is prepared using a vacuum laminator (V130 manufactured by Nikko Materials Co., Ltd.) in the following manner. - The adhesive layer is laminated onto a 775 μm 12-inch silicon wafer under the following conditions.・Laminating pressure: 0.5 MPa ・Upper platen temperature: 80°C, lower platen temperature: 40°C (Examples 1-2, Comparative Example 1) ・Upper platen temperature: 70°C, lower platen temperature: 40°C (Examples 3-4, Comparative Example 2) ・Vacuum setting pressure: 2.0 hPa ・Vacuuming time: 60 s ・Upper slap time: 0 (ineffective) ・Upper pressurization time: 120 s ・Lower vacuum: Yes (2) The imaging is performed by peeling off the adhesive tape, focusing on the outermost surface of the adhesive layer, and under the following conditions. ・Imaging locations: 5 points in total: 1 point in the center of the wafer (150 mm from the wafer edge), and 4 points 100 mm above, below, left, and right of the center. 1: Measurement device: Digital microscope (VHX-6000 manufactured by Keyence Corporation) Lens: VH-Z100UR Magnification: 200x Illumination: Coaxial incident illumination Transmitted illumination: None Shutter speed: 185 on auto Gain: 0 dB on manual (3) The analysis will be carried out as follows: Automatic area measurement and extraction method: Brightness Extraction target: Dark areas Threshold: -25 Hole filling and small particle removal: Uncheck (4) The number of defects with a maximum diameter of 5 μm or more will be counted from the measurement results and the average value will be used. (Evaluation criteria) 1: Number of defects is 101 or more 2: Number of defects is 51 to 100 3: Number of defects is 31 to 50 4: Number of defects is 11 to 30 5: Number of defects is 10 or less The results obtained are shown in Table 1.

[0167]

[0168] 1...Support substrate, 2...Film-like adhesive (adhesive layer), 3...Adhesive layer, 4...Substrate, 5...Adhesive tape, 6...Dicing tape, 7...Substrate, 8...Electrode, 9...Adhesive layer (film-like adhesive), 10...Adhesive tape, 11...Release film, 20...Semiconductor wafer, 22, 22a, 22b...Bump, 24, 24a, 24b...Solder ball, 26, 26a, 26b...Protruding electrode (solder bump), 28...Groove, 29, 29a, 29b...Semiconductor chip, 30, 30a, 30b...Semiconductor chip with adhesive layer, 31a, 31b...Electrode, 32a, 32b...Through-hole electrode, 100...Semiconductor device.

Claims

1. A semiconductor adhesive tape comprising a base material, an adhesive layer disposed on the base material, and an adhesive layer disposed on the adhesive layer, wherein the arithmetic mean roughness Sa of the surface of the adhesive layer furthest from the base material is 0.012 μm or less.

2. The semiconductor adhesive tape according to claim 1, wherein the maximum height Sz of the surface of the adhesive layer furthest from the substrate is 0.380 μm or less.

3. A method for manufacturing an adhesive tape for semiconductors, comprising: preparing an adhesive tape comprising a base material and an adhesive layer disposed on the base material, wherein the arithmetic mean roughness Sa of the surface of the adhesive layer on the side furthest from the base material is 0.012 μm or less; and forming an adhesive layer on the adhesive layer.

4. The method for manufacturing a semiconductor adhesive tape according to claim 3, wherein the maximum height Sz of the surface of the adhesive layer furthest from the substrate is 0.380 μm or less.

5. The method for manufacturing a semiconductor adhesive tape according to claim 3, wherein the adhesive tape is obtained by peeling off the release film from a laminate comprising the base material, an adhesive layer disposed on the base material, and a release film disposed on the adhesive layer, and the arithmetic mean roughness Sa of the surface of the release film that is in contact with the adhesive layer is 0.012 μm or less.

6. A method for manufacturing a semiconductor chip with an adhesive layer, comprising: attaching the semiconductor adhesive tape described in claim 1 or 2 to a semiconductor wafer from the adhesive layer side; polishing the side of the semiconductor wafer to which the adhesive tape is attached that is opposite to the adhesive tape; and separating the polished semiconductor wafer into individual pieces to obtain a semiconductor chip with an adhesive layer.

7. A method for manufacturing a semiconductor device comprising a plurality of semiconductor chips stacked together, comprising: placing a first semiconductor chip with an adhesive layer obtained by the method of claim 6 onto a substrate from the adhesive layer side, and pressing it together while heating to obtain a first laminate in which the substrate and the first semiconductor chip with an adhesive layer are stacked; and placing a second semiconductor chip with an adhesive layer obtained by the method of claim 6 onto the first laminate from the adhesive layer side, and pressing it together while heating to obtain a second laminate in which the substrate, the first semiconductor chip with an adhesive layer and the second semiconductor chip with an adhesive layer are stacked together.

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