Film adhesive for semiconductors and method for manufacturing same, adhesive tape and method for manufacturing same, semiconductor device and method for manufacturing same, and method for manufacturing coating liquid

Abstract

Disclosed is a film adhesive for semiconductors, containing: a thermosetting resin, a thermoplastic resin, a thermally conductive filler and a phosphoric acid-based dispersant. The content of the thermally conductive filler is 50 mass % or more based on the total amount of the film adhesive for semiconductors.

Description

Semiconductor film adhesive and method for manufacturing the same, adhesive tape and method for manufacturing the same, semiconductor device and method for manufacturing the same, and method for manufacturing coating liquid

[0001] This disclosure relates to a film-like adhesive for semiconductors and a method for manufacturing the same, an adhesive tape and a method for manufacturing the same, a semiconductor device and a method for manufacturing the same, and a method for manufacturing a coating liquid.

[0002] Traditionally, wire bonding, which uses thin metal wires such as gold wires, has been widely applied to connect semiconductor chips and substrates. In recent years, in order to meet the demands for high functionality, high integration, and high speed for semiconductor devices, the flip-chip connection method (FC connection method), which involves forming conductive protrusions called bumps on the semiconductor chip or substrate to directly connect the semiconductor chip and the substrate, is becoming increasingly widespread.

[0003] Known flip-chip connection methods include metal joining using solder, tin, gold, silver, copper, etc., metal joining by applying ultrasonic vibration, and maintaining mechanical contact by the shrinkage force of resin. Among these, metal joining using solder, tin, gold, silver, copper, etc. is the most common from the standpoint of connection reliability.

[0004] For example, in connecting semiconductor chips to substrates, the COB (Chip On Board) connection method, which is widely used in BGA (Ball Grid Array) and CSP (Chip Size Package), is also a flip-chip connection method. Furthermore, the flip-chip connection method is also widely used in the COC (Chip On Chip) connection method, which involves forming bumps or wiring on the semiconductor chip to connect semiconductor chips (see, for example, Patent Document 1).

[0005] In packages where further miniaturization, thinning, and high functionality are strongly demanded, chip stack type packages, POP (Package On Package), TSV (Through-Silicone Via), and other technologies that stack and multi-stage the above connection methods are beginning to become widely adopted. Because packages can be made smaller by arranging components in a three-dimensional rather than planar manner, these technologies are widely used and are effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, and are attracting attention as next-generation semiconductor wiring technologies.

[0006] Japanese Patent Publication No. 2008-294382

[0007] Incidentally, in the flip-chip connection method described above, flip-chip connections are sometimes made using a semiconductor film adhesive for purposes such as protecting the metal connections at the connection points.

[0008] In recent years, semiconductor packages have become remarkably more sophisticated and highly integrated, and consequently, the pitch between wirings tends to become narrower. Furthermore, the amount of heat generated from semiconductor chips has also increased, and in order to improve heat dissipation, there is a strong demand for semiconductor film adhesives to contain high concentrations of thermally conductive fillers (for example, 50% or more by mass based on the total amount of the semiconductor film adhesive).

[0009] However, when high concentrations of thermally conductive fillers are included in semiconductor film adhesives, the viscosity of the adhesive increases significantly, and its fluidity decreases, especially when heated and melted to fill the gaps between bumps. As a result, voids may occur because the gaps between circuits with narrow pitches cannot be completely filled, which can reduce connection reliability. Therefore, semiconductor film adhesives are required to have a sufficiently low viscosity when heated (for example, at 75°C) to ensure excellent embedding performance in narrow pitches.

[0010] Furthermore, in the connection process during the manufacturing of flip-chip packages, alignment is usually performed using alignment marks provided on the substrate or semiconductor chip as a guide. When flip-chip connections are made using a semiconductor film adhesive, the semiconductor chip or substrate to which the semiconductor film adhesive is applied is then aligned. Therefore, semiconductor film adhesives are required to have high visible light transmittance so that the covered alignment marks can be seen. It should be noted that generally, the visible light transmittance tends to decrease when thermally conductive fillers are included at high concentrations.

[0011] The primary objective of this disclosure is to provide a semiconductor film adhesive that can sufficiently reduce viscosity during heating, even when containing a high concentration of thermally conductive filler, and that also has sufficiently high visible light transmittance.

[0012] The present inventors conducted diligent studies to solve the above problems and discovered that, in a semiconductor film adhesive containing a high concentration of thermally conductive filler, by applying a predetermined dispersant, it is possible to sufficiently reduce the viscosity during heating and also achieve sufficiently high visible light transmittance, thus completing the invention disclosed herein.

[0013] This disclosure provides semiconductor film adhesives as described in [1] to

[11] , adhesive tapes as described in

[12] , methods for manufacturing semiconductor devices as described in

[13] and

[14] , semiconductor devices as described in

[15] and

[16] , methods for manufacturing coatings as described in

[17] , methods for manufacturing semiconductor film adhesives as described in

[18] , and methods for manufacturing adhesive tapes as described in

[19] . [1] A semiconductor film adhesive comprising a thermosetting resin, a thermoplastic resin, a thermally conductive filler, and a phosphate-based dispersant, wherein the content of the thermally conductive filler is 50% by mass or more based on the total amount of the semiconductor film adhesive. [2] The semiconductor film adhesive according to [1], wherein the phosphate-based dispersant is adsorbed on the thermally conductive filler. [3] The semiconductor film adhesive according to [1] or [2], wherein the thermally conductive filler is a filler composed of a substance having a thermal conductivity of 10 W / (m·K) or more at 20°C. [4] A semiconductor film adhesive according to any one of [1] to [3], wherein the thermally conductive filler is a filler composed of aluminum oxide. [5] A semiconductor film adhesive according to any one of [1] to [4], wherein the melt viscosity at 75°C is 4000 Pa·s or less. [6] A semiconductor film adhesive according to any one of [1] to [5], wherein the light transmittance for light with a wavelength of 550 nm is 50% or more. [7] A semiconductor film adhesive according to any one of [1] to [6], wherein the thermosetting resin contains an epoxy resin that is liquid at 25°C. [8] A semiconductor film adhesive according to any one of [1] to [7], further containing a curing agent. [9] A semiconductor film adhesive according to any one of [1] to [8], further containing a flux compound.

[10] A semiconductor film adhesive according to any one of [1] to [9], used to seal the connection portion in a semiconductor device having a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other.

[11] A semiconductor device having a connection structure in which the connection portions of multiple semiconductor chips are electrically connected to each other, wherein a semiconductor film adhesive according to any one of [1] to [9] is used to seal the connection portions.

[12] An adhesive tape comprising, in this order, a base layer, an adhesive layer, and a semiconductor film adhesive described in any of [1] to [9].

[13] A method for manufacturing a semiconductor device comprising a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, comprising the step of sealing at least a part of the connection portion using a semiconductor film adhesive described in any of [1] to [9].

[14] A method for manufacturing a semiconductor device comprising a connection structure in which the connection portions of a plurality of semiconductor chips are electrically connected to each other, comprising the step of sealing at least a part of the connection portion using a semiconductor film adhesive described in any of [1] to [9].

[15] A semiconductor device comprising a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and a sealing material for sealing at least a part of the connection portion, wherein the sealing material includes a cured product of a semiconductor film adhesive described in any of [1] to [9].

[16] A semiconductor device comprising: a connection structure in which the connection portions of a plurality of semiconductor chips are electrically connected to each other; and a sealing material that seals at least a part of the connection portions, wherein the sealing material includes a cured product of a semiconductor film adhesive according to any one of [1] to [9].

[17] A method for producing a coating liquid containing a thermosetting resin, a thermoplastic resin, a thermally conductive filler, and a phosphate-based dispersant, comprising: a step of mixing an organic solvent, the thermally conductive filler, and the phosphate-based dispersant to obtain a dispersion containing the thermally conductive filler and the phosphate-based dispersant; and a step of mixing the dispersion, the thermosetting resin, and the thermoplastic resin to obtain the coating liquid.

[18] A method for producing a semiconductor film adhesive, comprising: a step of applying the coating liquid obtained by the method for producing a coating liquid according to

[17] onto a substrate to form a coating film; and a step of reducing the amount of the organic solvent in the coating film by heating to form a semiconductor film adhesive.A method for manufacturing an adhesive tape, comprising: a step of preparing a semiconductor film adhesive as described in any of [1] to [9]; a step of preparing an adhesive tape comprising a base layer and an adhesive layer provided on the base layer; and a step of forming an adhesive tape by attaching the adhesive layer of the adhesive tape to the semiconductor film adhesive.

[0014] This disclosure provides a semiconductor film adhesive that, even when containing a high concentration of thermally conductive filler, can sufficiently reduce viscosity upon heating and has sufficiently high visible light transmittance. Furthermore, this disclosure provides a semiconductor device and a method for manufacturing the same using such a semiconductor film adhesive. Also, this disclosure provides an adhesive tape and a method for manufacturing the same using such a semiconductor film adhesive. Furthermore, this disclosure provides a method for manufacturing a coating liquid suitable for the production of such a semiconductor film adhesive. Finally, this disclosure provides a method for manufacturing a semiconductor film adhesive using such a coating liquid.

[0015] Figure 1 is a schematic cross-sectional view showing one embodiment of the semiconductor film adhesive of the present disclosure. Figures 2(a) and 2(b) are schematic cross-sectional views showing one embodiment of the semiconductor device of the present disclosure. Figures 3(a) and 3(b) are schematic cross-sectional views showing another embodiment of the semiconductor device of the present disclosure. Figure 4 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present disclosure. Figures 5(a) and 5(b) are schematic cross-sectional views showing an example of a method for manufacturing the semiconductor device shown in Figure 4. Figure 6 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present disclosure.

[0016] In this specification, "(meth)acryloyl" means at least one of acryloyl and its corresponding methacryloyl. The same applies to other similar expressions such as "(meth)acrylate". Furthermore, numerical ranges indicated using "~" indicate a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In addition, in numerical ranges described in this specification, the upper or lower limits 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 in any way. In addition, unless otherwise specified, the materials exemplified below may be used individually or in combination of two or more. The content of each component in the composition means the total amount of the multiple substances present in the composition if there are multiple substances corresponding to each component in the composition, unless otherwise specified.

[0017] The embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted. Furthermore, unless otherwise specified, positional relationships such as top, bottom, left, and right are based on the positional relationships shown in the drawings. Moreover, the dimensional ratios in the drawings are not limited to those shown.

[0018] <Film-type adhesive for semiconductors> One embodiment of a film-type adhesive for semiconductors (hereinafter sometimes simply referred to as "film-type adhesive") is suitably used to seal connection parts in a semiconductor device having a connection structure in which the connection parts of a semiconductor chip and a wiring circuit board are electrically connected to each other, or in a semiconductor device having a connection structure in which the connection parts of a plurality of semiconductor chips are electrically connected to each other.

[0019] Figure 1 is a schematic cross-sectional view showing a film-like adhesive according to one embodiment. The film-like adhesive 1 shown in Figure 1 contains a thermosetting resin (hereinafter sometimes referred to as "component (A)"), a thermoplastic resin (hereinafter sometimes referred to as "component (B)"), a thermally conductive filler (hereinafter sometimes referred to as "component (C)"), and a phosphate-based dispersant (hereinafter sometimes referred to as "component (D)"). The film-like adhesive 1 may further contain a curing agent (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)"), etc.

[0020] (A) Component: Thermosetting resin Component (A) is a component that hardens by forming three-dimensional bonds between molecules when heated, etc., and exhibits adhesive properties after hardening. Component (A) may be an epoxy resin. Component (A) can be used without particular limitations as long as it has epoxy groups in its molecule. Component (A) may be a compound having two or more epoxy groups in its molecule.

[0021] Component (A) may contain an epoxy resin that is solid at 25°C (hereinafter sometimes referred to as "component (A1)"). By including component (A1) in component (A), it tends to be easier to adjust the rheological properties of the film-like adhesive and control the minimum melt viscosity to a suitable range. Here, "solid at 25°C" means that the viscosity at 25°C, as measured by an E-type viscometer, is greater than 400 Pa·s.

[0022] Examples of component (A1) 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 (e.g., triphenolmethane type epoxy resin (triphenolmethane skeleton-containing epoxy resin)), dicyclopentadiene type epoxy resin, and various polyfunctional epoxy resins. Component (A1) may also contain triphenylmethane type epoxy resin (e.g., triphenolmethane type epoxy resin).

[0023] The epoxy equivalent of component (A1) may be 50 to 500 g / eq, or 100 to 400 g / eq or 120 to 370 g / eq.

[0024] Component (A) may contain an epoxy resin that is liquid at 25°C (hereinafter sometimes referred to as "component (A2)"). The inclusion of component (A2) in component (A) 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.

[0025] (A2) Examples of components include bisphenol A type glycidyl ether, bisphenol AD ​​type glycidyl ether, bisphenol S type glycidyl ether, bisphenol F type glycidyl ether, hydrogenated 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 glycidylamines, etc.

[0026] (A2) The epoxy equivalent of component may be 100 to 3000 g / eq, or 100 to 2000 g / eq or 100 to 1500 g / eq.

[0027] The content of component (A) may be 5% by mass or more, 10% by mass or more, or 15% by mass or more, based on the total amount of the film-like adhesive, and may be 40% by mass or less, 35% by mass or less, or 30% by mass or less, based on the total amount of the film-like adhesive. In other words, the content of component (A) may be 5 to 40% by mass, 10 to 35% by mass or 15 to 30% by mass, based on the total amount of the film-like adhesive.

[0028] 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-like 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, based on the total amount of the film-like adhesive. In other words, the content of component (A1) may be 3 to 30% by mass, 5 to 28% by mass, 8 to 26% by mass, 10 to 24% by mass, or 12 to 22% by mass, based on the total amount of the film-like adhesive.

[0029] 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, or 0.85 or less, from the viewpoint of easily obtaining good sealing properties and easily suppressing the generation of voids. In other words, the mass ratio of the content of component (A1) to the content of component (A) may be 0.50 to 1.00, 0.55 to 0.95, 0.60 to 0.90, or 0.65 to 0.85.

[0030] 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, or 0.15 or more, and may be 0.50 or less, 0.45 or less, 0.40 or less, or 0.35 or less. The mass ratio of the content of component (A2) to the content of component (A) may be 0 to 0.50, 0.05 to 0.45, 0.10 to 0.40, or 0.15 to 0.35.

[0031] (B) Component: Thermoplastic resin Component (B) is a polymer that softens at high temperatures and is a component that contributes to improved heat resistance and film formation properties.

[0032] Examples of component (B) 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 (B) 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.

[0033] The weight-average molecular weight of component (B) 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. From the viewpoint of easily obtaining the effect of improving heat resistance, the weight-average molecular weight of component (B) may be 1,000,000 or less, 500,000 or less, or 150,000 or less. That is, the weight-average molecular weight of component (B) may be 10,000 to 1,000,000, 20,000 to 500,000, or 30,000 to 150,000. In this specification, weight-average molecular weight means the weight-average molecular weight measured in polystyrene equivalent using high-performance liquid chromatography (for example, Shimadzu Corporation, product name: C-R4A). For measurement, for example, the following conditions can be used. 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

[0034] The glass transition temperature (Tg) of component (B) may be 120°C or lower, 100°C or lower, or 85°C or lower from the viewpoint of excellent adhesiveness of the film adhesive to a connecting member (for example, a semiconductor chip). Here, Tg means Tg measured using DSC (for example, product name: DSC-7, manufactured by PerkinElmer Inc.) under the conditions of a sample amount of 10 mg, a temperature increase rate of 10°C / min, and a measurement atmosphere of air.

[0035] The content of component (B) may be 0.5% by mass or more, 1% by mass or more, 2% by mass or more, or 3% by mass or more based on the total amount of the film adhesive. The content of component (B) may be 12% by mass or less, 10% by mass or less, 8% by mass or less, or 6% by mass or less based on the total amount of the film adhesive. That is, the content of component (B) may be 0.5 to 12% by mass, 1 to 10% by mass, 2 to 8% by mass, or 3 to 6% by mass based on the total amount of the film adhesive.

[0036] Component (C): Thermally conductive filler Component (C) is a filler composed of a substance having thermal conductivity. When the film adhesive contains component (C), a cured product of the film adhesive has excellent heat dissipation properties.

[0037] Component (C) may be, for example, a filler composed of a substance having a thermal conductivity of 10 W / (m·K) or more at 20°C. Component (C) can also be referred to as a filler 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. That is, component (C) may have a thermal conductivity at 20°C of 10 to 2000 W / (m·K), 10 to 1500 W / (m·K), 10 to 1000 W / (m·K), 10 to 500 W / (m·K), or 10 to 200 W / (m·K).

[0038] Examples of materials with a thermal conductivity (at 20°C) of 10 W / (m·K) or higher include oxides such as aluminum oxide (alumina, thermal conductivity (at 20°C): 30 W / (m·K)), zinc oxide (thermal conductivity (at 20°C): 60 W / (m·K)), magnesium oxide (thermal conductivity (at 20°C): 50 W / (m·K)), and boron nitride (thermal conductivity (at 20°C) of hexagonal boron nitride (h-BN): 60 W / (m·K) (representative value for sintered bodies. The crystal has great anisotropy, and the face Inward thermal conductivity reaches several hundred W / (m·K).), cubic boron nitride (c-BN) thermal conductivity (20°C): 300 W / (m·K) (high-quality materials exceed 1000 W / (m·K)), aluminum nitride (thermal conductivity (20°C): 160 W / (m·K)), silicon nitride (thermal conductivity (20°C): 25 W / (m·K)), and other nitrides, diamond (thermal conductivity (20°C): 2000 W / (m·K)), silicon carbide (thermal conductivity (20°C): 1 Carbides such as 95 W / (m·K), silver (thermal conductivity (20°C): 430 W / (m·K)), copper (thermal conductivity (20°C): 400 W / (m·K)), gold (thermal conductivity (20°C): 320 W / (m·K)), aluminum (thermal conductivity (20°C): 240 W / (m·K)), magnesium (thermal conductivity (20°C): 160 W / (m·K)), tungsten (thermal conductivity (20°C): 170 W / (m·K)), molybdenum (thermal conductivity (20°C): 1 Examples of metals with thermal conductivity include 40 W / (m·K), zinc (thermal conductivity (20°C): 120 W / (m·K)), nickel (thermal conductivity (20°C): 90 W / (m·K)), iron (thermal conductivity (20°C): 80 W / (m·K)), platinum (thermal conductivity (20°C): 70 W / (m·K)), tin (thermal conductivity (20°C): 70 W / (m·K)), lead (thermal conductivity (20°C): 35 W / (m·K)), and titanium (thermal conductivity (20°C): 20 W / (m·K)).

[0039] In one embodiment, the component (C) may be a filler composed 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, and may be 150 W / (m·K) or less, 120 W / (m·K) or less, 100 W / (m·K) or less, 80 W / (m·K) or less, 60 W / (m·K) or less, or 40 W / (m·K) or less. That is, the component (C) may have a thermal conductivity (at 20°C) of 20 to 150 W / (m·K), 20 to 120 W / (m·K), 20 to 100 W / (m·K), 20 to 80 W / (m·K), 20 to 60 W / (m·K), or 20 to 40 W / (m·K).

[0040] In one embodiment, the component (C) may 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, and may also be a filler composed of at least one substance selected from the group consisting of aluminum oxide, magnesium oxide, boron nitride, and aluminum nitride.

[0041] In one embodiment, the component (C) may be a filler composed of a metal, which may be a filler composed 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 also be a filler composed of silver or copper.

[0042] For example, the component (C) may be a filler composed of aluminum oxide (alumina) (alumina filler). From the viewpoints of further improving thermal conductivity after thermosetting and preventing electromigration during operation of a semiconductor device, the alumina filler may be a filler composed of low-chlorine alumina with a purity of 99.0% by mass or more. The component (C) may be a filler composed of α-alumina having a purity of 99.0% by mass or more.

[0043] The shape of component (C) is not particularly limited, but may be spherical, needle-shaped, plate-shaped, flaky, etc., or it may be polyhedron-shaped.

[0044] The average particle size of component (C) may be, for example, 0.01 to 5 μm. The average particle size of component (C) may be 3 μm or less or 2 μm or less, or 0.05 μm or more or 0.1 μm or more. That is, the average particle size of component (C) may be 0.01 to 3 μm, 0.01 to 2 μm, 0.05 to 5 μm, 0.05 to 3 μm, 0.05 to 2 μm, 0.1 to 5 μm, 0.1 to 3 μm, or 0.1 to 2 μm. Note that the average particle size of component (C) is the particle size at the point corresponding to 50% of the volume (median diameter (D50)) 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 with a particle size distribution analyzer using laser diffraction scattering or the like.

[0045] Component (C) may be surface-treated with a coupling agent. Examples of coupling agents include silane coupling agents and titanium coupling agents. Examples of silane coupling agents include (meth)acryloyloxysilane, aminosilane, phenylaminosilane, imidazolesilane, phenylsilane, vinylsilane, and epoxysilane.

[0046] The content of component (C) 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 (C) may be 55% by mass or more, 60% by mass or more, or 65% by mass or more, based on the total amount of the film-like adhesive. The content of component (C) may be, for example, 90% by mass or less, 85% by mass or less, or 80% by mass or less, based on the total amount of the film-like adhesive. That is, the content of component (C) may be 50 to 90% by mass, 55 to 90% by mass, 60 to 85% by mass, or 65 to 80% by mass, based on the total amount of the film-like adhesive.

[0047] Component (D): Phosphate-based dispersant. Component (D) is a component (dispersant) that contributes to improving the dispersibility of component (C). When a film adhesive contains component (D), it is possible to sufficiently reduce its viscosity when heated, and it also has sufficiently high visible light transmittance. The reason for these effects is not entirely clear, but it is presumed that component (D) is strongly adsorbed to component (C), and the chain structure of the dispersant promotes slippage between particles, thereby suppressing particle aggregation even at high concentrations of component (C), and simultaneously achieving viscosity reduction and improved visible light transmittance when heated.

[0048] Component (D) typically has a phosphate group that can act as an adsorption site and a chain-like structure that can act as a steric repulsion site.

[0049] Examples of phosphate groups include the phosphate group (-OPO(OH) ２ Examples include phosphate derivative groups derived from phosphate groups. These may form salts with organic amines (e.g., triethanolamine, diethanolamine, monoethanolamine, triethylamine, dimethylethanolamine, etc.), ammonia, or metal ions (e.g., sodium, potassium, calcium, magnesium, zinc, aluminum, etc.). Specific examples of amine salt type dispersants include triethanolamine salt, diethanolamine salt, and ammonium salt. Specific examples of metal salt type dispersants include sodium salt, potassium salt, calcium salt, and magnesium salt.

[0050] Examples of phosphate derivative groups include phosphate ester groups. Examples of phosphate ester groups include -OPO(OR １１ ) ( OR １２ ) (Caution １１ and R １２ This refers to alkyl groups having 1 to 30 carbon atoms, aryl groups having 6 to 30 carbon atoms, etc.

[0051] Examples of chain-like structures include polyoxyalkylene chains, polyester chains, poly(meth)acrylate chains, polyurethane chains, and polyamide chains.

[0052] Component (D) may be a monofunctional dispersant having one phosphate group per molecule, or a polyfunctional dispersant having two or more phosphate groups per molecule. A monofunctional dispersant may, for example, be a dispersant having one phosphate group and a chain-like structure linked to the phosphate group. A polyfunctional dispersant may, for example, be a dispersant having a main chain and multiple side chains, wherein the main chain has two or more phosphate groups and the side chains have a chain-like structure. Component (D) may contain a monofunctional dispersant because it can more sufficiently reduce viscosity when heated.

[0053] Examples of commercially available monofunctional dispersants include DISPERBYK®-111, DISPERBYK-103, DISPERBYK-110, BYK-W903, and BYK-W996 (manufactured by BYK, trade names).

[0054] Examples of commercially available polyfunctional dispersants include DISPERBYK®-145 and BYK-9076 (manufactured by BYK, trade name).

[0055] In a film-like adhesive, component (D) may be adsorbed onto component (C). The adsorption site for component (D) may be, for example, a phosphate group. Adsorbing component (D) onto component (C) tends to further reduce the viscosity of the film-like adhesive when heated. Methods for adsorbing component (D) onto component (C) include, for example, mixing and kneading an organic solvent, component (C), and component (D). The organic solvent used in this method may be the same as the organic solvent used in the preparation of the dispersion and 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.

[0056] The content of component (D) may be 0.1 parts by mass or more, 0.3 parts by mass or more, or 0.5 parts by mass or more, and may be 5 parts by mass or less, 4 parts by mass or less, or 3 parts by mass or less, per 100 parts by mass of component (C). When the content of component (D) is within this range, there is a tendency to further reduce the viscosity of the film-like adhesive when heated. That is, the content of component (D) may be 0.1 to 5 parts by mass, 0.3 to 4 parts by mass, or 0.5 to 3 parts by mass, per 100 parts by mass of component (C).

[0057] (E) Component: Curing agent Examples of (E) 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.

[0058] 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.

[0059] Examples of acid anhydride-based curing agents include methylcyclohexanetetracarboxylic acid dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic acid dianhydride, and ethylene glycol bisanhydrotrimellitate.

[0060] Examples of amine-based curing agents include dicyandiamide.

[0061] Examples of imidazole-based curing agents include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, and 2,4-diamino-6 Examples include -[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and imidazoles. Among these, imidazole-based curing agents are selected from the viewpoint of excellent curing properties, storage stability, and connection reliability, including 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine. These may be 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, or 2-phenyl-4-methyl-5-hydroxymethylimidazole. These imidazole-based curing agents may be microencapsulated and used as latent curing agents.

[0062] Examples of phosphine-based curing agents include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium (4-fluorophenyl)borate.

[0063] Component (E) 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 decomposition or deterioration due to moisture absorption less likely, and may contain an imidazole curing agent.

[0064] The content of component (E) may be 0.1 to 20 parts by mass, 0.5 to 15 parts by mass, or 1 to 10 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.

[0065] (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.

[0066] 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 (C) is suppressed due to the interaction between component (C) and component (D) and steric hindrance due to the steric repulsion site of component (D), and the increase in viscosity tends to be suppressed even more easily.

[0067] Component (F) may be a compound having a group represented by formula (1).

[0068]

[0069] In formula (1), R １ This indicates a hydrogen atom or an electron-donating group.

[0070] R １ From the viewpoint of superior reflow resistance and even greater connection reliability, it may be an electron-donating group.

[0071] Examples of electron-donating groups include alkyl groups, hydroxyl groups, amino groups, alkoxy groups, and alkylamino groups. The electron-donating group may be a group that does not readily react with other components (for example, component (A)), and more specifically, it may be an alkyl group, a hydroxyl group, or an alkoxy group, and may be an alkyl group.

[0072] The alkyl group may be linear or branched, and may preferably be linear. The alkyl group may be an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. The electron donating property and steric hindrance tend to increase as the number of carbon atoms in the alkyl group increases. An alkyl group having a number of carbon atoms within such a range is excellent in the balance between electron donating property and steric hindrance.

[0073] Examples of flux compounds having two carboxy groups include compounds represented by formula (2). According to the compound represented by formula (2), the reflow resistance and connection reliability of a semiconductor device can be further improved.

[0074]

[0075] In formula (2), R １ has the same definition as R in formula (1) １ and represents a hydrogen atom or an electron donating group. R ２ represents a hydrogen atom or an electron donating group, and n represents 0 or an integer of 1 or more.

[0076] R ２ The electron donating group represented by includes the same electron donating groups as those exemplified for R １ . R ２ may be the same as or different from R １ . When a plurality of R ２ groups are present, they may be the same as or different from each other.

[0077] n in formula (2) may be 1 or more. When n is 1 or more, compared to the case where n is 0, the flux compound is less likely to volatilize even at high temperatures during connection, and the generation of voids can be further suppressed. n in formula (2) may be 15 or less, 11 or less, 6 or less, or 4 or less. When n is 15 or less, further excellent connection reliability tends to be obtained.

[0078] Specific examples of flux compounds having two carboxyl groups include dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, and dodecanediic acid; and compounds in which an electron-donating group is substituted at the 2-position of these dicarboxylic acids (for example, 2-methylglutaric acid). Among these, the flux compound having two carboxyl groups may be glutaric acid or 2-methylglutaric acid, from the viewpoint of further improving the effect of void reduction and sealing performance when combined with components (A) and (B).

[0079] The melting point of component (F) may be 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 component (F) may be 25°C or higher, or 50°C or higher. That is, the melting point of component (F) may be 25 to 150°C, 25 to 140°C, or 50 to 130°C. 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 0.01% by mass or more or 0.1% 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 3% by mass or less, 2% by mass or less, or 1% 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. That is, the content of component (F) may be 0.01 to 3% by mass, 0.1 to 3% by mass, 0.01 to 2% by mass, 0.1 to 2% by mass, 0.01 to 1% by mass, or 0.1 to 1% by mass, based on the total amount of the film-like adhesive.

[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 (B).

[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, or 0.1 μm or more, or 0.2 μm or more. That is, the average particle size of component (G) may be 0.01 to 3 μm, 0.1 to 2 μm, or 0.2 to 1 μm. Note that 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 with a particle size distribution analyzer using laser diffraction scattering or the like.

[0083] The content of component (G) may be, for example, 0.01% by mass or more, 0.1% by mass or more, or 0.2% by mass or more, and 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. In other words, the content of component (G) may be 0.01 to 5% by mass, 0.1 to 3% by mass, or 0.2 to 2% by mass, based on the total amount of the film-like adhesive.

[0084] Other additives in film-type adhesives 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 to ensure that the effects of each additive are realized.

[0085] The thickness of the film-like adhesive 1 may be, for example, 1 to 100 μm, and may also be 2 to 70 μm, 3 to 50 μm, or 4 to 30 μm.

[0086] The melt viscosity of the film-type adhesive at 75°C may be 4000 Pa·s or less. When the melt viscosity of the film-type adhesive at 75°C is 4000 Pa·s or less, the decrease in fluidity can be further suppressed, and the embedding ability tends to be more sufficiently ensured. The melt viscosity of the film-type adhesive at 75°C may be 3500 Pa·s or less, 3000 Pa·s or less, 2600 Pa·s or less, 2200 Pa·s or less, 1800 Pa·s or less, or 1400 Pa·s or less. The melt viscosity of the film-type adhesive at 75°C may be, for example, 300 Pa·s or more or 500 Pa·s or more. In other words, the melt viscosity of the film-like adhesive at 75°C may be 300 to 4000 Pa·s, 500 to 4000 Pa·s, 300 to 3500 Pa·s, 500 to 3500 Pa·s, 300 to 3000 Pa·s, 500 to 3000 Pa·s, 300 to 2600 Pa·s, 500 to 2600 Pa·s, 300 to 2200 Pa·s, 500 to 2200 Pa·s, 300 to 1800 Pa·s, 500 to 1800 Pa·s, 300 to 1400 Pa·s, or 500 to 1400 Pa·s.

[0087] The melt viscosity of a film-type adhesive at 75°C can be measured, for example, by the following procedure. First, prepare several sheets of film-type adhesive. Next, stack the several sheets of film-type adhesive and laminate them until the thickness reaches 400 μm to prepare a sample for viscosity measurement. Lamination can be performed, for example, under conditions of a device setting temperature of 60°C and device transport speed level 3. Punch out a 10 mm square from the viscosity measurement sample and measure the melt viscosity (Pa·s) using a rotary rheometer under the following measurement conditions. Read the viscosity value at 75°C from the measured value and use this as the melt viscosity at 75°C. (Measurement conditions) Measurement tool size: 8 mmφ Sample thickness: 400 μm Heating rate: 10°C / min Frequency: 10 Hz Temperature range: 40 to 160°C

[0088] The light transmittance of the film-like adhesive to light with a wavelength of 550 nm may be 50% or more. When the light transmittance of the film-like adhesive to light with a wavelength of 550 nm is 50% or more, the visibility of the alignment marks tends to be better. The light transmittance of the film-like adhesive to light with a wavelength of 550 nm may be 51% or more, 52% or more, 53% or more, 54% or more, or 55% or more. The light transmittance of the film-like adhesive to light with a wavelength of 550 nm may be, for example, 90% or less or 80% or less. The light transmittance of the film-like adhesive to light with a wavelength of 550 nm may be 51-90%, 51-80%, 52-90%, 52-80%, 53-90%, 53-80%, 54-90%, 54-80%, 55-90%, or 55-80%.

[0089] The light transmittance of a film-like adhesive for light at a wavelength of 550 nm can be measured, for example, by the following procedure. First, a transmittance measurement sample is prepared by forming a 7 μm thick film-like adhesive on a PET separator film. Next, the obtained transmittance measurement sample and the PET separator film alone are each cut to a size of 30 mm x 30 mm. Then, the cut transmittance measurement sample is placed in the sample mounting section of the spectrophotometer, and the cut PET separator film alone is placed in the reference mounting section, and the light transmittance is measured in the wavelength range of 400 to 800 nm at a scan speed of 300 nm / min. The transmittance at a wavelength of 550 nm is read from the measured value and this is taken as the light transmittance for light at a wavelength of 550 nm.

[0090] The film-like adhesive 1 may be non-conductive. That is, the film-like adhesive 1 may be a so-called NCF (Non-Conductive Film).

[0091] The film-like adhesive 1 may be used as a multilayer film-like adhesive with two or more layers by laminating it with other film-like adhesives.

[0092] <Adhesive Tape> The film-like adhesive 1 may be provided with a substrate such as a support film or protective film on one main surface and / or the other main surface. In this disclosure, as one embodiment, a laminate comprising a film-like adhesive and a substrate provided on the film-like adhesive is referred to as "adhesive tape".

[0093] Examples of the base material include the same base material used in the method for manufacturing the film-like adhesive described later. The base material may be an adhesive tape comprising a base layer and an adhesive layer provided on the base layer, and the adhesive tape may be a backgrind tape. Examples of the base layer include the same base material used in the method for manufacturing the film-like adhesive described later. A preferred embodiment of the present disclosure is an adhesive tape (adhesive tape with adhesive tape) comprising a base layer, an adhesive layer, and a film-like adhesive in this order. The adhesive tape with adhesive tape may be an adhesive tape with a backgrind tape.

[0094] Adhesive tapes are typically configured such that one main surface is the adhesive layer. However, in adhesive tapes, the adhesive tape is placed on the film-like adhesive 1 such that the film-like adhesive and the adhesive layer are in contact. The thickness of the substrate (for example, the thickness of the adhesive tape) may be 20 to 300 μm.

[0095] The adhesive tape may be a laminate of a substrate and a film-like adhesive obtained by a method for manufacturing a film-like adhesive described later, that is, by applying a coating liquid to a substrate, forming a coating film, and drying it, or it may be a laminate obtained by attaching a substrate to the film-like adhesive 1 (for example, laminating the film-like adhesive 1 and the substrate).

[0096] When the substrate is an adhesive tape, applying and drying the coating liquid on the adhesive layer of the adhesive tape may cause problems such as damage to the adhesive layer or migration of components between the adhesive and the bonding agent. Therefore, the adhesive tape may be manufactured by a method that includes the steps of preparing a film-like adhesive 1 and an adhesive tape, and forming the adhesive tape by attaching the adhesive layer of the adhesive tape to the film-like adhesive 1.

[0097] <Method for manufacturing film-like adhesive for semiconductors> Film-like adhesive 1 can be obtained by a method that includes the step of forming an adhesive layer (film-like adhesive) on a substrate (for example, a substrate film). When forming an adhesive layer on a substrate, for example, first prepare a coating solution containing component (A), component (B), component (C), component (D), other components added as needed (component (E), component (F), component (G), and other additives), and an organic solvent.

[0098] When forming an adhesive layer on a substrate, the coating solution may be prepared as follows. For example, first, a dispersion is obtained by mixing (kneading) an organic solvent, component (C), and component (D). For example, when adding components (C) and (D) to the organic solvent, components (C) and (D) may be added simultaneously, or either component (C) or (D) may be added first and the other later. Subsequently, the coating solution is obtained by mixing (kneading) the dispersion, component (A), component (B), and other components added as needed (components (E), (F), (G), and other additives). For example, when adding components (A), (B), and other components added as needed to the dispersion, components (A), (B), and other components added as needed may be added in any order. In other words, the coating liquid may be manufactured by a method comprising the steps of: obtaining a dispersion containing components (C) and (D) by mixing (kneading) an organic solvent, component (C), and component (D); and obtaining a coating liquid containing components (A), (B), (C), and (D) by mixing (kneading) the dispersion, component (A), and component (B). In this way, by mixing (kneading) components (C) and (D) in advance, component (D) can be adsorbed onto component (C) more reliably.

[0099] Subsequently, the prepared coating solution is applied to the substrate (for example, a substrate that has undergone a release treatment) using a knife coater, roll coater, applicator, etc., to form a coating film, and then the organic solvent in the coating film is reduced by heating. This allows for the formation of an adhesive layer (film-like adhesive).

[0100] In other words, one embodiment of a method for manufacturing a film-like adhesive for semiconductors comprises the steps of applying a coating liquid onto a substrate to form a coating film, and reducing the amount of organic solvent in the coating film by heating to form a film-like adhesive for semiconductors.

[0101] The organic solvent used in preparing the dispersion and coating solution may have the property of uniformly dissolving or dispersing each component. Examples of organic solvents include dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. Mixing and kneading during the preparation of the dispersion and coating solution can be carried out using, for example, a stirrer, a sloshing machine, a three-roll mill, a ball mill, a bead mill, a homodisper, etc.

[0102] The substrate is not particularly limited as long as it has heat resistance that can withstand the heating conditions when volatilizing organic solvents. Examples of substrates include polyolefin films such as polypropylene film and polymethylpentene film; polyester films such as polyethylene terephthalate film and polyethylene naphthalate film; polyimide films; and polyetherimide films. The substrate is not limited to a single layer made of these films, but may also be a multilayer film made of two or more materials. The substrate may also be a film with a release treatment applied to its surface.

[0103] The drying conditions for volatilizing the organic solvent from the coating on the substrate are not particularly limited as long as the conditions allow for sufficient volatilization of the organic solvent. The heating temperature may be 50 to 200°C, and the heating time (holding time) may be 0.1 to 90 minutes. If there is no effect on voids or viscosity adjustment after mounting, the drying conditions may be such that the organic solvent is removed to 1.5% by mass or less based on the total amount of the film-like adhesive.

[0104] <Semiconductor Device> A semiconductor device manufactured using the film adhesive of this embodiment will be described. The semiconductor device of this embodiment comprises a connection structure in which the connection parts of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a connection structure in which the connection parts of a plurality of semiconductor chips are electrically connected to each other, and a sealing material that seals at least a part of the connection parts, the sealing material including a cured product of the film adhesive of this embodiment. The connection parts in the semiconductor device may be either metal bonding between bumps and wiring, or metal bonding between bumps. In the semiconductor device of this embodiment, for example, a flip-chip connection can be used to obtain an electrical connection via the film adhesive.

[0105] Figures 2(a) and 2(b) are schematic cross-sectional views showing an embodiment of a semiconductor device (a COB-type connection configuration of a semiconductor chip and a substrate). As shown in Figure 2(a), the semiconductor device 100 comprises a semiconductor chip 10 and a substrate (wiring circuit board) 20 facing each other, wiring 15 arranged on the opposing surfaces of the semiconductor chip 10 and the substrate 20, connecting bumps 30 connecting the wiring 15 of the semiconductor chip 10 and the substrate 20 to each other, and a sealing material 40 filled in the gap between the semiconductor chip 10 and the substrate 20. The semiconductor chip 10 and the substrate 20 are flip-chip connected by the wiring 15 and the connecting bumps 30. The wiring 15 and the connecting bumps 30 are sealed by the sealing material 40 and isolated from the external environment. The sealing material 40 includes a cured film-like adhesive of this embodiment.

[0106] As shown in Figure 2(b), the semiconductor device 200 comprises a semiconductor chip 10 and a substrate 20 facing each other, bumps 32 arranged on the opposing surfaces of the semiconductor chip 10 and the substrate 20, and a sealing material 40 filled in the gap between the semiconductor chip 10 and the substrate 20. The semiconductor chip 10 and the substrate 20 are connected via a flip-chip connection by the opposing bumps 32 being connected to each other. The bumps 32 are sealed by the sealing material 40 and isolated from the external environment.

[0107] Figures 3(a) and 3(b) are schematic cross-sectional views showing other embodiments of semiconductor devices (COC-type connection configurations between semiconductor chips). As shown in Figure 3(a), the semiconductor device 300 is the same as the semiconductor device 100 except that two semiconductor chips 10 are flip-chip connected by wiring 15 and connecting bumps 30. As shown in Figure 3(b), the semiconductor device 400 is the same as the semiconductor device 200 except that two semiconductor chips 10 are flip-chip connected by bumps 32.

[0108] The semiconductor chip 10 is not particularly limited, and various semiconductors can be used. Examples of semiconductor chips 10 include elemental semiconductors composed of the same type of element, such as silicon and germanium; and compound semiconductors, such as gallium arsenide and indium phosphide.

[0109] The substrate 20 is not particularly limited as long as it is a wiring circuit board. Examples of substrate 20 include circuit boards in which wiring (wiring patterns) are formed by etching away unnecessary parts of a metal layer formed on the surface of an insulating substrate mainly composed of glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimidotriazine, polyimide, etc., circuit boards in which wiring (wiring patterns) are formed on the surface of an insulating substrate by metal plating, etc., and circuit boards in which wiring (wiring patterns) are formed by printing a conductive material on the surface of an insulating substrate.

[0110] The connection parts such as the wiring 15 and bumps 32 may contain gold, silver, copper, solder (whose main components may be, for example, tin-silver, tin-lead, tin-bismuth, or tin-copper), nickel, tin, lead, etc., and may contain multiple metals.

[0111] A metal layer may be formed on the surface of the wiring (wiring pattern), mainly composed of gold, silver, copper, solder (for example, tin-silver, tin-lead, tin-bismuth, or tin-copper), tin, nickel, etc. This metal layer may consist of only a single component or multiple components. Furthermore, the metal layer may be a single layer or a multilayer structure in which multiple metal layers are stacked. Because they are inexpensive and commonly used, the metal layer may be copper or solder, but since oxides and impurities are usually present, flux activity may be required.

[0112] The main materials used for conductive protrusions called bumps include gold, silver, copper, solder (for example, those primarily composed of tin-silver, tin-lead, tin-bismuth, or tin-copper), tin, and nickel. The bump material may consist of a single component or multiple components. Furthermore, the bump may have a structure in which multiple components are layered. The bump may be formed on a semiconductor chip or substrate. Because they are inexpensive and commonly used, bumps may be made of copper or solder, but since oxides and impurities are usually present, flux activity may be required.

[0113] The semiconductor devices (packages) shown in Figures 2(a) and 2(b) or Figures 3(a) and 3(b) may be stacked and electrically connected with gold, silver, copper, solder (for example, those mainly composed of tin-silver, tin-lead, tin-bismuth, or tin-copper), tin, nickel, etc. The connections may be made with copper or solder because they are inexpensive and commonly used, but flux activity may be required because oxides and impurities are usually present. For example, as is often used in TSV technology, a film-like adhesive may be interposed between semiconductor chips for flip-chip connection or stacking, forming holes that penetrate the semiconductor chips and electrically connecting them to the electrodes on the pattern surface.

[0114] Figure 4 is a schematic cross-sectional view showing another embodiment of a semiconductor device (a semiconductor chip stacked type (TSV)). In the semiconductor device 500 shown in Figure 4, the semiconductor chip 10 and the interposer 50 are connected via a flip-chip connection by the wiring 15 formed on the interposer 50 being connected to the wiring 15 of the semiconductor chip 10 via connecting bumps 30. The gap between the semiconductor chip 10 and the interposer 50 is filled with a sealing material 40. On the surface of the semiconductor chip 10 opposite to the interposer 50, semiconductor chips 10 are repeatedly stacked via the wiring 15, connecting bumps 30, and sealing material 40. The wiring 15 on the pattern surfaces on the front and back of the semiconductor chip 10 are connected to each other by through-electrodes 34 filled in holes that penetrate the inside of the semiconductor chip 10. Copper, aluminum, and the like can be used as the material for the through-electrodes 34.

[0115] This TSV technology allows signals to be acquired from the back surface of semiconductor chips, which are not normally used. Furthermore, because the through-electrode 34 is passed vertically through the semiconductor chip 10, the distance between opposing semiconductor chips 10, or between the semiconductor chip 10 and the interposer 50, is shortened, enabling flexible connections. The film-like adhesive of this embodiment can be applied as a sealing material between opposing semiconductor chips 10, or between the semiconductor chip 10 and the interposer 50, in this TSV technology.

[0116] Furthermore, with highly flexible bump formation methods such as area bump chip technology, semiconductor chips can be directly mounted to the motherboard without the need for an interposer. The film adhesive of this embodiment can also be applied when directly mounting such semiconductor chips to the motherboard. In addition, the film adhesive of this embodiment can also be applied when sealing the gap between two wiring circuit boards when stacking them.

[0117] Figure 6 is a schematic cross-sectional view showing another embodiment of a semiconductor device (a COB-type connection configuration of a semiconductor chip and a substrate). In the semiconductor device 600 shown in Figure 6, a substrate (glass epoxy substrate) 60 having wiring (copper wiring) 15 and a semiconductor chip 10 having wiring (copper pillars, copper posts, etc.) 15 are connected to each other via a sealing material 40. The wiring 15 of the semiconductor chip 10 and the wiring 15 of the substrate 60 are electrically connected by connection bumps (solder bumps) 30. Solder resist 70 is placed on the surface of the substrate 60 where the wiring 15 is formed, except for the positions where the connection bumps 30 are formed. The semiconductor chip 10 may have through-electrodes.

[0118] <Method for Manufacturing a Semiconductor Device> The method for manufacturing a semiconductor device of this embodiment is a method for manufacturing a semiconductor device comprising a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, or a method for manufacturing a semiconductor device comprising a connection structure in which the connection portions of a plurality of semiconductor chips are electrically connected to each other, and comprises a step of sealing at least a part of the connection portion using the film adhesive of this embodiment.

[0119] This process can be carried out by using the film-like adhesive of this embodiment to connect a semiconductor chip and a wiring circuit board, or multiple semiconductor chips to each other. In this case, the semiconductor device manufacturing method of this embodiment may include, for example, a step of connecting a semiconductor chip and a wiring circuit board to each other via the film-like adhesive and electrically connecting the respective connection parts of the semiconductor chip and the wiring circuit board to each other, and / or a step of connecting multiple semiconductor chips to each other via the film-like adhesive and electrically connecting the respective connection parts of the multiple semiconductor chips to each other.

[0120] In the semiconductor device manufacturing method of this embodiment, connection parts can be connected to each other by metal bonding. That is, the connection parts of a semiconductor chip and a wiring circuit board can be connected to each other by metal bonding, or the connection parts of multiple semiconductor chips can be connected to each other by metal bonding.

[0121] As an example of a semiconductor device manufacturing method of this embodiment, a manufacturing method for the semiconductor device 500 shown in Figure 4 will be described. In the semiconductor device 500, the semiconductor chip 10 and the interposer 50 are connected via a flip-chip connection, where wiring (copper wiring) 15 formed on the interposer 50 is connected to wiring (copper pillars, copper posts, etc.) 15 on the semiconductor chip 10 via connecting bumps (solder bumps) 30. The gap between the semiconductor chip 10 and the interposer 50 is filled with a sealing material 40. On the surface of the semiconductor chip 10 opposite to the interposer 50, semiconductor chips 10 are repeatedly stacked via wiring 15, connecting bumps 30, and sealing material 40. The wiring 15 on the pattern surfaces on the front and back of the semiconductor chip 10 are connected to each other by through electrodes 34 filled in holes that penetrate the inside of the semiconductor chip 10.

[0122] Figures 5(a) and 5(b) illustrate an example of a semiconductor device manufacturing method shown in Figure 4. Figure 5(a) shows a process of pressing a laminated chip, on which a film-like adhesive is provided on the main surface of a semiconductor chip, with another semiconductor chip via the film-like adhesive. The laminated chip (semiconductor chips to be stacked) 700 comprises a semiconductor chip 10 and a film-like adhesive 42 provided on the main surface of the semiconductor chip 10. The semiconductor chip 10 is provided with through-electrodes 34 filled in holes penetrating the interior of the semiconductor chip 10, wiring 15 arranged on one surface of the semiconductor chip 10, and connection bumps 30 arranged on the wiring 15. The film-like adhesive 42 is provided to embed the wiring 15 and the connection bumps 30, but may cover at least a portion of the surface of the semiconductor chip 10, the wiring 15, and the connection bumps 30.

[0123] The stacked chip 700 can be manufactured by attaching a film-like adhesive 42 to a semiconductor wafer having wiring 15 and connecting bumps 30, and then dicing it to separate it into individual semiconductor chips 10. The film-like adhesive can be attached by methods such as heat pressing, roll lamination, or vacuum lamination.

[0124] The crimping of the multilayer chip 700 with another semiconductor chip can be performed, for example, by aligning the connection bumps 30 of the multilayer chip 700 so as to electrically connect with through-electrodes 34 filled in holes penetrating the interior of the other semiconductor chip 10, and then using a crimping tool 90 while heating the multilayer chip 700 and the semiconductor chip 10 at a temperature above the melting point of the connection bumps 30 (if solder is used at the connection point, the temperature applied to the soldered portion may be 240°C or higher). This connects the multilayer chip 700 and the semiconductor chip 10, and seals the connection point with a cured film-like adhesive.

[0125] The connection load depends on the number of bumps, but is set appropriately considering the absorption of variations in bump height and the control of bump deformation. The connection time may be short from the viewpoint of improving productivity. The connection time may be the time required to melt the solder, remove oxide film and surface impurities, and form a metal bond at the connection point. A short connection time (crimping time) means that the time during connection formation (main crimping) when the connection point is subjected to a temperature of 240°C or higher (for example, the time when solder is used) is 10 seconds or less. The connection time may be 5 seconds or less or 3 seconds or less. The same method can be applied to the connection between the interposer 50 having wiring 15 and the multilayer chip 700.

[0126] By repeating this process, the semiconductor device 500 shown in Figure 5(b) can be manufactured. Alternatively, the semiconductor device 500 can also be manufactured by repeatedly aligning and stacking (temporarily fixing) the stacked chip 700 and the semiconductor chip 10 to obtain a multi-layer stacked structure with temporary fixing, and then heating it in a reflow oven to melt the solder bumps and connect the semiconductor chips together. Since temporary fixing does not significantly require the formation of metal joints, it can be performed with lower load, in a shorter time, and at a lower temperature compared to permanent bonding, which has advantages in terms of improved productivity and prevention of deterioration of the connection part. After connecting the semiconductor chip and the substrate, the film-like adhesive may be cured by heating it in an oven or the like. The heating temperature may be the temperature at which the film-like adhesive proceeds to harden completely. The heating temperature and heating time can be set as appropriate.

[0127] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0128] Examples 1-4 and Comparative Example 1 <Preparation of film-like adhesives> (Preparation of materials) The following materials were prepared.(A) Components: Thermosetting resin (A1) Components: Epoxy resin that is solid at 25°C (A1-1) Triphenolmethane skeleton-containing polyfunctional solid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jER1032H60, "jER" is a registered trademark (hereinafter the same), epoxy equivalent: 163-175 g / eq, softening point: 62°C) (A2) Components: Epoxy resin that is liquid at 25°C (A2-1) Bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jERYL983U, epoxy equivalent: 165-175 g / eq) (A2-2) Flexible epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jERYX7110B80, epoxy equivalent: 950-1250 g / eq) (B) Components: Thermoplastic resin (B-1) Phenoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., product name: ZX-1356-2, Tg: approx. 71°C, weight-average molecular weight Mw: approx. 63000) (C) Component: Thermally conductive filler (C-1) Alumina filler (shape: spherical (perfect sphere), median diameter (D50): 0.2 μm) (D) Component: Phosphate-based dispersant (D-1) Monofunctional dispersant (compound having a phosphate ester group, manufactured by BYK, product name: DISPERBYK-111, "DISPERBYK" is a registered trademark (hereinafter the same)) (D-2) Monofunctional dispersant (metal salt of a compound having a phosphate ester group, manufactured by BYK, product name: BYK-W903) (D-3) Polyfunctional dispersant (amine salt of a compound having a phosphate ester group, manufactured by BYK, product name: DISPERBYK-145) (D-4) Polyfunctional dispersant (amine salt of a compound having a phosphate group, manufactured by BYK, trade name: BYK-9076) (d) Component: Dispersant other than phosphate-based dispersant (d-1) Polyfunctional dispersant (compound having a carboxyl group, manufactured by NOF Corporation, trade name: Marialim SC-0505K, "Marialim" is a registered trademark) (E) Component: Curing agent (E-1) 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct (manufactured by Shikoku Chemicals, Ltd., trade name: 2MAOK-PW) (F) Component: Flux compound (F-1) Glutaric acid (manufactured by Aldrich, melting point: approximately 98°C) (G) Component: Organic filler (G-1) Core-shell type organic microparticles (manufactured by Rohm & Haas Japan Co., Ltd., trade name: EXL-2655).

[0129] (Example 1) First, a dispersion containing components (C) and (D) shown in Table 1 was prepared. An organic solvent (cyclohexanone) was prepared so that the NV value ([solid content mass] / [dispersion mass] × 100) was 70% of the amounts (unit: parts by mass) of components (C) and (D) shown in Table 1. The amounts shown in Table 1 represent the amount of solids. Next, component (D) was added to the organic solvent and stirred for 10 minutes at a rotation speed of 500 rpm using a homodisper (PRIMIX) to obtain a preliminary dispersion. Then, component (C) was added to the preliminary dispersion, followed by the addition of Φ1.0 mm beads, and stirred for 30 minutes at a rotation speed of 360 rpm using a bead mill (P-7 planetary pulverizer, Fritsch Japan Co., Ltd.). The amount of beads added was equal in mass to the total amount of components other than the organic solvent. After stirring, the beads were removed by filtration to obtain a dispersion. Furthermore, it is presumed that in the dispersion, component (D) is adsorbed onto component (C).

[0130] Next, components other than components (C) and (D) shown in Table 1 were added to the organic solvent (cyclohexanone) so that the NV value ([solid content mass] / [mixture mass] × 100) was 60%. At this time, the amount of each component added was as shown in Table 1 (unit: parts by mass). Note that the amount shown in Table 1 represents the amount of solid content. After that, Φ1.0 mm beads were added and stirred for 30 minutes at a rotation speed of 360 rpm using a bead mill (Fritsch Japan Co., Ltd., planetary type fine grinder P-7). The amount of beads added was equal in mass to the total amount of components other than the organic solvent. After stirring, the beads were removed by filtration to obtain a mixture containing components other than components (C) and (D).

[0131] Next, a dispersion containing components (C) and (D) was mixed with a mixture containing components other than (C) and (D). Then, these were stirred for 30 minutes at a rotation speed of 1000 rpm using a homodisper (manufactured by PRIMIX) to obtain a coating solution for forming a film-like adhesive.

[0132] Using the obtained coating solution, a film-like adhesive of Example 1 was prepared. Specifically, first, the coating solution was applied to a base film (Toyobo Co., Ltd., product name: Purex A54) using a small precision coating device (Yasui Seiki Co., Ltd.) so that the thickness after drying would be 7 μm. Next, the coating film was dried in a clean oven (ESPEC Corporation) at 100°C for 5 minutes to obtain a film-like adhesive of Example 1 with a thickness of 7 μm.

[0133] (Example 2) Except that the (D) component was changed from 5.5 parts by mass of (D-1) to 5.5 parts by mass of (D-2), a film-like adhesive of Example 2 with a thickness of 7 μm was obtained in the same manner as in Example 1.

[0134] (Example 3) Except that the (D) component was changed from 5.5 parts by mass of (D-1) to 5.5 parts by mass of (D-3), a film-like adhesive of Example 3 with a thickness of 7 μm was obtained in the same manner as in Example 1.

[0135] (Example 4) Except that the (D) component was changed from 5.5 parts by mass of (D-1) to 5.5 parts by mass of (D-4), a film-like adhesive of Example 4 with a thickness of 7 μm was obtained in the same manner as in Example 1.

[0136] (Comparative Example 1) A film-like adhesive of Comparative Example 1 with a thickness of 7 μm was obtained in the same manner as in Example 1, except that the (D) component was changed from 5.5 parts by mass of (D-1) to 5.5 parts by mass of (d-1).

[0137] <Evaluation of Film-Like Adhesives> (Measurement of Melt Viscosity) Using the film-like adhesives obtained in the examples and comparative examples, multiple sheets of the film-like adhesive were stacked and laminated to a thickness of 400 μm using a desktop laminator (manufactured by Lamy Corporation, product name: Hotdog Leon 13DX) to prepare samples for viscosity measurement. Lamination was performed under the conditions of a device setting temperature of 60°C and device transport speed level 3. The viscosity measurement samples were punched out into 10 mm squares, and the melt viscosity (Pa·s) was measured using a rotary rheometer (manufactured by TA Instruments, product name: ARES) under the following measurement conditions. The viscosity value at 75°C was read from the measured value and this was taken as the melt viscosity at 75°C. The results are shown in Table 1. (Measurement Conditions) Measurement tool size: 8 mmφ Sample thickness: 400 μm Heating rate: 10°C / min Frequency: 10 Hz Temperature range: 40 to 160°C

[0138] (Measurement of Light Transmittance) First, a transmittance measurement sample was prepared by forming a 7 μm thick film-like adhesive on a PET separator film. Next, the obtained transmittance measurement sample and the PET separator film alone were each cut to a size of 30 mm x 30 mm. The cut transmittance measurement sample was placed in the sample mounting section of the spectrophotometer, and the cut PET separator film alone was placed in the reference mounting section. Light transmittance was measured in the wavelength range of 400 to 800 nm at a scan speed of 300 nm / min. The transmittance at a wavelength of 550 nm was read from the measured value and this was taken as the light transmittance for light at a wavelength of 550 nm. The results are shown in Table 1.

[0139]

[0140] As shown in Table 1, the film-like adhesives of Examples 1 to 4 containing components (C) and (D) showed a decrease in melt viscosity at 75°C and an improvement in light transmittance for light at a wavelength of 550 nm compared to the film-like adhesive of Comparative Example 1 containing components (C) and (d). These results confirm that the film-like adhesive of the present disclosure can sufficiently reduce viscosity during heating, even when containing a high concentration of thermally conductive filler, and also has sufficiently high visible light transmittance.

[0141] 1, 42...Film-type adhesive (film-type adhesive for semiconductors), 10...Semiconductor chip, 15...Wiring, 20, 60...Substrate, 30...Connecting bump, 32...Bump, 34...Through-hole electrode, 40...Sealing material, 50...Interposer, 70...Solder resist, 90...Crimping tool, 100, 200, 300, 400, 500, 600...Electronic equipment, 700...Multilayer chip.

Claims

1. A film-type adhesive for semiconductors, comprising a thermosetting resin, a thermoplastic resin, a thermally conductive filler, and a phosphate-based dispersant, wherein the content of the thermally conductive filler is 50% by mass or more based on the total amount of the film-type adhesive for semiconductors.

2. The semiconductor film adhesive according to claim 1, wherein the phosphate-based dispersant is adsorbed onto the thermally conductive filler.

3. The semiconductor film adhesive according to claim 1 or 2, wherein the thermally conductive filler is a filler composed of a substance having a thermal conductivity of 10 W / (m·K) or more at 20°C.

4. The semiconductor film adhesive according to claim 1 or 2, wherein the thermally conductive filler is a filler composed of aluminum oxide.

5. A semiconductor film adhesive according to claim 1 or 2, wherein the melt viscosity at 75°C is 4000 Pa·s or less.

6. The semiconductor film adhesive according to claim 1 or 2, wherein the light transmittance for light with a wavelength of 550 nm is 50% or more.

7. The semiconductor film adhesive according to claim 1 or 2, wherein the thermosetting resin comprises an epoxy resin that is liquid at 25°C.

8. The semiconductor film adhesive according to claim 1 or 2, further comprising a curing agent.

9. The semiconductor film adhesive according to claim 1 or 2, further comprising a flux compound.

10. A semiconductor device having a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, and a semiconductor film adhesive according to claim 1 or 2, used for sealing the connection portions.

11. A semiconductor device having a connection structure in which the connection portions of multiple semiconductor chips are electrically connected to each other, and a semiconductor film adhesive according to claim 1 or 2, used for sealing the connection portions.

12. An adhesive tape comprising, in this order, a base layer, an adhesive layer, and a semiconductor film adhesive according to claim 1 or 2.

13. A method for manufacturing a semiconductor device, comprising a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other, the method comprising the step of sealing at least a part of the connection portion using a semiconductor film adhesive as described in claim 1 or 2.

14. A method for manufacturing a semiconductor device having a connection structure in which the connection portions of a plurality of semiconductor chips are electrically connected to each other, comprising the step of sealing at least a part of the connection portions using a semiconductor film adhesive as described in claim 1 or 2.

15. A semiconductor device comprising: a connection structure in which the connection portions of a semiconductor chip and a wiring circuit board are electrically connected to each other; and a sealing material that seals at least a portion of the connection portions, wherein the sealing material includes a cured product of the semiconductor film adhesive described in claim 1 or 2.

16. A semiconductor device comprising: a connection structure in which the connection portions of a plurality of semiconductor chips are electrically connected to each other; and a sealing material that seals at least a portion of the connection portions, wherein the sealing material includes a cured product of the semiconductor film adhesive described in claim 1 or 2.

17. A method for producing a coating liquid containing a thermosetting resin, a thermoplastic resin, a thermally conductive filler, and a phosphate-based dispersant, comprising: a step of obtaining a dispersion containing the thermally conductive filler and the phosphate-based dispersant by mixing an organic solvent, the thermally conductive filler, and the phosphate-based dispersant; and a step of obtaining the coating liquid by mixing the dispersion, the thermosetting resin, and the thermoplastic resin.

18. A method for producing a film-like adhesive for semiconductors, comprising the steps of: applying a coating liquid obtained by the method for producing a coating liquid according to claim 17 onto a substrate to form a coating film; and reducing the amount of the organic solvent in the coating film by heating to form a film-like adhesive for semiconductors.

19. A method for manufacturing an adhesive tape, comprising the steps of: preparing a film-like adhesive for semiconductors according to claim 1 or 2; preparing an adhesive tape comprising a base layer and an adhesive layer provided on the base layer; and forming an adhesive tape by attaching the adhesive layer of the adhesive tape to the film-like adhesive for semiconductors.

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