Adhesive for semiconductor, adhesive sheet for semiconductor, and production method for semiconductor device

Abstract

To provide an adhesive for semiconductors that enables the reliable connection of a semiconductor chip to a wiring circuit board or another semiconductor chip, through a flip-chip connection system, even after subjected to thermal history for a long time.SOLUTION: The present invention provides an adhesive for semiconductors containing a thermosetting resin, a curing agent, and a flux compound having an acid group. The adhesive has a calorific value of 20 J / g or less at 60°C to 155°C on a DSC curve, as determined by differential scanning calorimetry involving heating the adhesive at a rate of temperature increase of 10°C / min. In the DSC curve, the onset temperature of the exothermic peak from the curing reaction is 150°C or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an adhesive for semiconductors, an adhesive sheet for semiconductors, and a method for manufacturing a semiconductor device. [Background technology]

[0002] In manufacturing semiconductor devices, a flip-chip connection method is sometimes adopted in which a semiconductor chip having bumps as connection parts is directly connected to connection parts (electrodes) of a wiring circuit board via the bumps. In the flip-chip connection method, an underfill that fills the gap between the semiconductor chip and the wiring circuit board and seals the connection parts is generally formed with an adhesive.

[0003] A known method for forming an underfill is to inject a liquid resin into the gap between a semiconductor chip and a wiring circuit board after connecting the semiconductor chip and the wiring circuit board (see Patent Document 1). An underfill may also be formed using an adhesive film such as anisotropic conductive adhesive film (ACF) or non-conductive adhesive film (NCF) (see Patent Document 2).

[0004] In order to achieve high functionality and high-speed operation, through silicon vias (TSVs), a three-dimensional packaging technology that connects semiconductor chips over the shortest distance, have been attracting attention (see Non-Patent Document 1). To achieve this, there is a demand to make semiconductor wafers as thin as possible while maintaining their mechanical strength. In order to make semiconductor wafers thinner, a process known as back grinding, in which the back surface of the semiconductor wafer is ground, may be performed. In order to simplify the back grinding process, resins that combine the function of holding the semiconductor wafer and the function as an underfill material have also been proposed (see Patent Documents 3 and 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2000-100862 A [Patent Document 2] JP 2003-142529 A [Patent Document 3] JP 2001-332520 A [Patent Document 4] JP 2005-028734 A [Non-patent literature]

[0006] [Non-Patent Document 1] OKI Technical Review, October 2007 / Issue 211, Vol. 74, No. 3 Summary of the Invention [Problem to be solved by the invention]

[0007] As semiconductor chips are arranged in multiple stages, adhesives used to connect semiconductor chips to wiring circuit boards or other semiconductor chips by flip-chip connection tend to be left in the temperature range of 60° C. to 80° C. for longer periods before heating for connection. When a semiconductor chip is connected to a wiring circuit board or other semiconductor chips through an adhesive that has been subjected to a thermal history, sufficient connection reliability may not be obtained.

[0008] Therefore, one aspect of the present invention provides a semiconductor adhesive that enables a semiconductor chip to be connected to a wiring circuit board or another semiconductor chip with high reliability using a flip chip connection method, even after being subjected to a long period of thermal history. [Means for solving the problem]

[0009] One aspect of the present invention provides a semiconductor adhesive comprising a thermosetting resin, a curing agent, and a flux compound having an acid group. The adhesive for semiconductors is heated at a temperature rise rate of 10°C / min and the heat release value in a DSC curve between 60 and 155°C is 20 J / g or less. In the DSC curve, the onset temperature of the exothermic peak due to the curing reaction is 150°C or more.

[0010] Another aspect of the present invention provides an adhesive sheet for a semiconductor comprising a supporting substrate and an adhesive layer provided on the supporting substrate and made of the above-mentioned adhesive for a semiconductor.

[0011] Yet another aspect of the present invention provides a process for forming a bonded body, the bonded body being formed by heating and pressurizing a semiconductor chip having a plurality of connection portions and a wiring circuit board having a plurality of connection portions while an adhesive is interposed between the semiconductor chip, the wiring circuit board, and the adhesive, so that the connection portions of the semiconductor chip and the connection portions of the wiring circuit board are electrically connected to each other, and at least a portion of the connection portions electrically connected to each other are sealed by the hardened adhesive; a step of forming a bonded body in which a plurality of semiconductor chips each having a plurality of connection parts are electrically connected to each other by heating and pressurizing the semiconductor chips and the adhesive while an adhesive is interposed between the semiconductor chips, and at least a portion of the connection parts electrically connected to each other are sealed by the hardened adhesive; A process for forming a bonded body in which an adhesive is interposed between a semiconductor chip having a plurality of connection parts and a semiconductor wafer having a plurality of connection parts, and the semiconductor chip, the semiconductor wafer, and the adhesive are heated and pressurized, so that the connection parts of the semiconductor chip and the connection parts of the semiconductor wafer are electrically connected to each other, and at least a part of the electrically connected connection parts is sealed by the hardened adhesive. The present invention provides a method for producing a semiconductor device, comprising at least one step selected from the following: The adhesive is the adhesive for semiconductor according to one aspect of the present invention. Effect of the Invention

[0012] According to one aspect of the present invention, there is provided an adhesive for semiconductors that enables a semiconductor chip to be connected to a wiring circuit board or another semiconductor chip with high reliability using a flip-chip connection method, even after being subjected to a long period of thermal history at a temperature of, for example, approximately 60 to 80°C. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of an adhesive sheet. [Diagram 2] FIG. 2 is a schematic diagram showing a method for determining an onset temperature from a DSC curve. [Diagram 3] FIG. 2 is a schematic diagram showing a method for determining the calorific value from 60 to 155° C. from a DSC curve. [Figure 4] FIG. 2 is a schematic diagram showing a method for determining the calorific value from 60 to 155° C. from a DSC curve. [Diagram 5] FIG. 1 is a schematic cross-sectional view showing one embodiment of an adhesive sheet. [Figure 6] 1A to 1C are schematic cross-sectional views showing an embodiment of a method for manufacturing a semiconductor device. [Figure 7] 1A to 1C are schematic cross-sectional views showing an embodiment of a method for manufacturing a semiconductor device. [Figure 8] 1A to 1C are schematic cross-sectional views showing an embodiment of a method for manufacturing a semiconductor device. [Figure 9] 1A to 1C are schematic cross-sectional views showing an embodiment of a method for manufacturing a semiconductor device. [Figure 10] 1A to 1C are schematic cross-sectional views showing an embodiment of a method for manufacturing a semiconductor device. [Figure 11] 1A to 1C are schematic cross-sectional views showing an embodiment of a method for manufacturing a semiconductor device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, several embodiments of the present invention will be described in detail, however, the present invention is not limited to the following embodiments.

[0015] Fig. 1 is a schematic cross-sectional view showing one embodiment of an adhesive sheet. The adhesive sheet 10 shown in Fig. 1 is an adhesive sheet for a semiconductor including a supporting substrate 3, an adhesive layer 2 provided on the supporting substrate 3, and a protective film 1 covering the adhesive layer 2.

[0016] The adhesive layer 2 is a layer formed of a thermosetting adhesive. The adhesive forming the adhesive layer 2 is a semiconductor adhesive containing (A) a thermosetting resin, (B) a curing agent, and (C) a flux compound having an acid group.

[0017] The heat generation amount in the range of 60 to 155°C in the DSC curve obtained by differential scanning calorimetry in which the adhesive is heated at a temperature increase rate of 10°C / min is 20 J / g or less. In the DSC curve, the onset temperature of the exothermic peak due to the curing reaction is 150°C or higher.

[0018] Here, the differential scanning calorimetry is performed by heating the adhesive in an air or nitrogen atmosphere with a weight of 10 mg of a sample semiconductor adhesive, a measurement temperature range of 30 to 300°C, and a heating rate of 10°C / min. The DSC curve is a graph showing the relationship between the amount of heat generated and the temperature obtained by differential scanning calorimetry. The amount of heat generated is calculated by integrating the peak area.

[0019] Conventional semiconductor adhesives containing thermosetting resins and flux compounds generally have an exothermic peak in the temperature range of 60 to 155 ° C. on the DSC curve, and the amount of heat generated in this temperature range exceeds 20 J / g. It is presumed that the heat generated in this temperature range is due to the reaction between the thermosetting resin and the flux compound in the semiconductor adhesive. When the semiconductor adhesive is subjected to a long-term thermal history, the reaction between the thermosetting resin and the flux compound proceeds, and as a result, the fluidity of the adhesive is thought to decrease. This decrease in fluidity is thought to be one of the causes of the decrease in connection reliability. If the amount of heat generated in the DSC curve from 60 to 155 ° C. is 20 J / g or less and the onset temperature of the exothermic peak due to the curing reaction is 150 ° C. or higher as in the adhesive according to this embodiment, the adhesive is likely to maintain sufficient fluidity even when subjected to a thermal history before connection. As a result, it is thought that the semiconductor chip and the wiring circuit board or other semiconductor chips can be connected with high reliability by the flip chip connection method even after the adhesive is subjected to a long-term thermal history.

[0020] Fig. 2 is a schematic diagram showing a method for determining the onset temperature from a DSC curve. The DSC curve shown in Fig. 1 includes a baseline L0 in the temperature range of 60 to 280°C, and an exothermic peak P due to the curing reaction of the adhesive observed halfway through the baseline L0. The onset temperature is the temperature T at the intersection between an extension line L1 of the baseline L0 below the exothermic peak P and a tangent line L2 to the DSC curve at the point where the DSC curve shows the maximum gradient at the exothermic peak P.

[0021] 3 and 4 are schematic diagrams showing a method for determining the calorific value from 60 to 155°C from a DSC curve. As shown in FIG. 3, when the DSC curve includes only the exothermic peak P including a portion below 155°C as an exothermic peak, the calorific value Q1 of the portion below 155°C of the exothermic peak P is the calorific value from 60 to 155°C. The calorific value Q1 is determined from the area of ​​the region below 155°C surrounded by the exothermic peak P and an extension line L1 of the baseline L0. As shown in FIG. 4, when the DSC curve further includes a peak other than the exothermic peak P in the region below 155°C, the sum of the calorific value Q2 of the peak and the calorific value Q1 of the exothermic peak P below 155°C is the calorific value from 60 to 155°C. When more exothermic peaks are observed in the region below 60 to 155°C, the calorific value obtained by adding up all the calorific values ​​of those exothermic peaks is the calorific value from 60 to 155°C.

[0022] The onset temperature may be 155° C. or higher, or 160° C. or higher, and may be 200° C. or lower, 190° C. or lower, or 180° C. or lower. The calorific value at 60 to 155° C. may be 15 J / g or lower, or 10 J / g or lower, or may be 0 J / g. The onset temperature and the calorific value at 60 to 155° C. can be controlled mainly by the type and content of the thermosetting resin, the curing agent, and the fluxing agent.

[0023] The thermosetting resin of the (A) component is not particularly limited. For example, epoxy resin, unsaturated polyester resin, melamine resin, urea resin, diallyl phthalate resin, bismaleimide resin, triazine resin, polyurethane resin, phenol resin, cyanoacrylate resin, polyisocyanate resin, furan resin, resorcinol resin, xylene resin, benzoguanamine resin, silicone resin, siloxane-modified epoxy resin, and siloxane-modified polyamideimide resin can be mentioned. These can be used alone or in a mixture of two or more. From the viewpoint of improving heat resistance and adhesiveness, the (A) component may contain an epoxy resin.

[0024] The epoxy resin is not particularly limited as long as it has an adhesive action when cured, and for example, epoxy resins described in the Epoxy Resin Handbook (edited by Masaki Shinbo, Nikkan Kogyo Shimbun) can be widely used. Specifically, for example, bifunctional epoxy resins such as bisphenol A type epoxy, novolac type epoxy resins such as phenol novolac type epoxy resins and cresol novolac type epoxy resins, and trisphenol methane type epoxy resins can be used. Generally known epoxy resins such as multifunctional epoxy resins, glycidylamine type epoxy resins, heterocyclic epoxy resins, and alicyclic epoxy resins can also be applied.

[0025] When the adhesive contains a thermoplastic resin described below, the content of the (A) component may be 5 to 88 parts by mass, 20 to 50 parts by mass, 20 to 40 parts by mass, or 15 to 35 parts by mass per 100 parts by mass of the total amount of the thermosetting resin and the thermoplastic resin in order to maintain the heat resistance and adhesiveness of the adhesive after curing and to exhibit high reliability. When the content of the (A) component is 5 parts by mass or more, even higher connection reliability is easily obtained. When the content of the (A) component is 88 parts by mass or less, the adhesive layer is easily able to maintain its shape.

[0026] From the viewpoint of suppressing decomposition and generation of volatile components during connection at high temperatures, if the temperature during connection is 250°C, a thermosetting resin with a thermal weight loss rate of 5% or less at 250°C may be used. If the temperature during connection is 300°C, a thermosetting resin with a thermal weight loss rate of 5% or less at 300°C may be used.

[0027] The curing agent of the component (B) may include an imidazole-based curing agent. The imidazole-based curing agent is an imidazole derivative. By appropriately selecting the imidazole-based curing agent, it is easy to obtain an adhesive having a calorific value of 20 J / g at 60 to 155°C and an onset temperature of 150°C or higher. From this viewpoint, for example, an imidazole-based curing agent having a melting point of 210°C or higher may be used.

[0028] Examples of imidazole-based hardeners 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, 2,4-diamino-6- Examples of the epoxy resin 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 isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resin and imidazoles. Among these, 2-phenyl-4,5-dihydroxymethylimidazole may be used from the viewpoint of excellent curing property and control of onset temperature.

[0029] The content of the curing agent (or imidazole-based curing agent) may be 0.1 to 45 parts by mass relative to 100 parts by mass of the (A) component. When the (A) component content is 0.1 part by mass or more, a sufficient curing reaction speed is easily obtained. When the (A) component content is 45 parts by mass or less, good heat resistance and adhesiveness are easily maintained.

[0030] The average particle size of the curing agent (or imidazole-based curing agent) may be 10 μm or less, 5 μm or less, or 2 μm or less from the viewpoint of ensuring dispersibility and flatness of the adhesive layer. If the average particle size is more than 10 μm, the curing agent tends to settle in the varnish for forming the adhesive layer.

[0031] The flux compound of component (C) may be an organic acid having a carboxyl group.

[0032] When the component (C) melts, it removes oxides on the metal surfaces that constitute the connecting parts, thereby improving the solder wettability of the adhesive layer 2. Therefore, the component (C) may have a melting point lower than the melting point of the solder that constitutes the connecting parts.

[0033] Component (C) is usually dissolved in the organic solvent used to prepare the resin varnish. Then, in the process of forming the adhesive layer, the organic solvent is evaporated by heating, causing the dissolved component (C) to precipitate again, and the fine powder of the flux compound is uniformly present in the adhesive layer. This increases the specific surface area of ​​the flux compound and increases the number of contact points with the oxide film, making it easier to remove the oxide film and improving solder connectivity.

[0034] The melting point of the (C) component may be 50 to 200° C., from the viewpoint that the fluxing property is improved by melting and liquefying the fine powder flux compound during thermocompression bonding. When the melting point of the flux compound is within this range, higher connection reliability is likely to be obtained.

[0035] The melting point of the flux compound can be measured using a general melting point measurement device. The sample to be measured is ground into a fine powder and a small amount is used to reduce the temperature deviation inside the sample. A capillary tube with one end closed is often used as the container for the sample, but some measurement devices use a container sandwiched between two microscope cover glasses. In addition, if the temperature is increased suddenly, a temperature gradient will occur between the sample and the thermometer, causing measurement errors, so it is desirable to increase the temperature at the time of measuring the melting point at a rate of less than 1°C per minute.

[0036] The content of the component (C) may be 0.1 to 20 parts by mass, or 0.5 to 10 parts by mass, relative to 100 parts by mass of the adhesive. When the content of the component (C) is within this range, good solder wettability is easily ensured.

[0037] The adhesive layer can be formed, for example, using a resin varnish containing (A) a thermosetting resin, (B) a curing agent, (C) a flux compound, and an organic solvent. The organic solvent used to prepare the resin varnish is not particularly limited, but can be selected in consideration of the boiling point of dissolving the (A) component and the (C) component and the volatility during the formation of the adhesive layer. Specifically, for example, when a resin varnish containing a solvent with a relatively low boiling point such as ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, toluene, or xylene is used, the adhesive layer is less likely to harden during the formation of the adhesive layer. These solvents can be used alone or in combination of two or more.

[0038] The adhesive of the present embodiment may contain a thermoplastic resin (hereinafter referred to as component (D)) as necessary. An adhesive containing component (D) has even more excellent heat resistance and film formability.

[0039] Examples of component (D) include polyester resin, polyether resin, polyamide resin, polyamideimide resin, polyimide resin, polyvinyl butyral resin, polyvinyl formal resin, phenoxy resin, polyhydroxypolyether resin, acrylic resin, polystyrene resin, butadiene resin, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-styrene resin, styrene-butadiene copolymer, and acrylic acid copolymer. These can be used alone or in combination of two or more.

[0040] The component (D) can improve the film formability of the adhesive. Film formability means a mechanical property that the adhesive layer does not easily tear, crack, or become sticky when a film-like adhesive layer is formed by the adhesive. If the adhesive is easy to handle as a film under normal conditions (for example, at room temperature), the film formability can be said to be good. Among the above-mentioned thermoplastic resins, polyimide resin or phenoxy resin may be used because of its excellent heat resistance and mechanical strength.

[0041] The content of component (D) may be 10 to 50 parts by mass, 15 to 40 parts by mass, or 20 to 35 parts by mass, based on 100 parts by mass of the total amount of component (D) (thermoplastic resin) and component (A) (thermosetting resin). When the content of component (D) is within this range, the adhesive exhibits good film-forming properties, exhibits fluidity during thermocompression bonding, and exhibits good resin removal properties between the bumps and the circuit electrodes.

[0042] The weight average molecular weight of component (D) may be 10,000 to 800,000, 30,000 to 500,000, 35,000 to 100,000, or 40,000 to 80,000. When the weight average molecular weight is within this range, it becomes easy to achieve a good balance between the strength and flexibility of the sheet- or film-shaped adhesive layer 2, and the flowability of the adhesive layer 2 becomes good, so that the circuit filling ability (embedding ability) of the wiring can be sufficiently ensured. In this specification, the weight average molecular weight means a value measured by gel permeation chromatography and converted using a standard polystyrene calibration curve.

[0043] From the viewpoint of imparting tackiness and adhesion to the adhesive layer before curing while maintaining film formability, the glass transition temperature of component (D) may be 20 to 170° C., or 25 to 120° C. If the glass transition temperature of component (D) is less than 20° C., the film formability at room temperature decreases, and the adhesive layer 2 tends to be easily deformed during processing of the semiconductor wafer in the back grinding step. If the glass transition temperature of component (D) is 170° C. or lower, the effect of improving the connection reliability of the adhesive after being subjected to thermal history can be more significantly achieved.

[0044] The adhesive of the present embodiment may contain an inorganic filler (hereinafter referred to as component (E)) as necessary. Component (E) can control the viscosity of the adhesive, the physical properties of the cured product of the adhesive, etc. Specifically, component (E) can, for example, suppress the generation of voids during connection, reduce the moisture absorption rate of the cured product of the adhesive, etc.

[0045] By including the adhesive as component (E), the moisture absorption rate and linear expansion coefficient of the adhesive layer 2 after curing can be reduced and the elastic modulus can be increased, thereby improving the connection reliability of the semiconductor device to be manufactured. As the component (E), an inorganic filler that does not reduce the visible light transmittance can be selected in order to prevent scattering of visible light in the adhesive layer 2 and improve the visible light transmittance. As the component (E) capable of suppressing the decrease in visible light transmittance, an inorganic filler having a particle size smaller than the wavelength of visible light may be selected, or an inorganic filler having a refractive index close to that of the adhesive may be selected.

[0046] The component (E) having a particle size smaller than the wavelength of visible light is not particularly limited in terms of the composition of the filler as long as it is a filler having transparency. The average particle size of the inorganic filler may be less than 0.3 μm, or 0.1 μm or less. The refractive index of the inorganic filler may be 1.46 to 1.7.

[0047] As the component (E) having a refractive index close to that of the adhesive, an adhesive is prepared, the refractive index is measured, and then an inorganic filler having a refractive index close to that refractive index can be selected. As the inorganic filler, a fine filler may be used from the viewpoint of filling the gap between the semiconductor chip and the wiring circuit board in the adhesive layer and from the viewpoint of suppressing the generation of voids in the connection process. The average particle size of the inorganic filler may be 0.01 to 5 μm, 0.1 to 2 μm, or 0.3 to 1 μm. If the average particle size of the inorganic filler is less than 0.01 μm, the surface area of ​​the particles increases, the viscosity of the adhesive increases, the embedding property in the protruding electrode becomes poor, and voids tend to remain. If the average particle size exceeds 5 μm, visible light scattering occurs, and the visible light transmittance tends to decrease.

[0048] The refractive index of the component (E), which has a refractive index close to that of the adhesive, may be in the range of ±0.06 of the refractive index of the adhesive. For example, when the refractive index of the adhesive is 1.60, the refractive index of the inorganic filler may be 1.54 to 1.66. The refractive index can be measured using an Abbe refractometer with sodium D line (589 nm) as a light source.

[0049] Examples of inorganic fillers include composite oxide fillers, composite hydroxide fillers, barium sulfate, and clay minerals. More specifically, for example, cordierite, phorusite, mullite, barium sulfate, magnesium hydroxide, aluminum borate, barium, or silica titania can be used. These inorganic fillers can be used in combination of two or more.

[0050] From the viewpoint of improving the elastic modulus of the adhesive layer, the linear expansion coefficient of the (E) component is set to 7×10 -6 / ℃ or less, or 3×10 -6 / °C or less.

[0051] The content of the (E) component may be 25 to 200 parts by mass, 50 to 150 parts by mass, or 75 to 125 parts by mass, based on 100 parts by mass of the adhesive excluding the (E) component. If the content of the (E) component is less than 25 parts by mass, the adhesive layer formed from the adhesive is likely to have an increased linear expansion coefficient and a decreased elastic modulus. This tends to reduce the connection reliability between the semiconductor chip and the wiring circuit board after pressure bonding, and further makes it difficult to obtain the effect of suppressing voids during connection. If the content of the (E) component exceeds 200 parts by mass, the melt viscosity of the adhesive increases, and the wettability of the interface between the semiconductor chip and the adhesive layer 2 or the interface between the circuit board and the adhesive layer 2 decreases, making it easier for peeling or residual voids due to insufficient filling to occur.

[0052] The adhesive of this embodiment may contain an organic filler (hereinafter referred to as component (F)) as necessary. The adhesive properties of the adhesive can be controlled by the component (F). The component (F) is generally not soluble in organic solvents, so it can be incorporated into the adhesive while maintaining its particle shape. This allows the component (F) to be dispersed in islands in the adhesive layer 2 after curing, and the strength of the connection body can be maintained high. This allows the adhesive to function as an impact mitigation agent having stress relaxation properties.

[0053] Examples of the component (F) include copolymers containing acrylic resin, silicone resin, butadiene rubber, polyester, polyurethane, polyvinyl butyral, polyarylate, polymethyl methacrylate, acrylic rubber, polystyrene, NBR, SBR, silicone-modified resin, and the like as components.

[0054] From the viewpoint of improving dispersibility in adhesives, stress relaxation properties, and adhesive properties, the (F) component may be an organic filler having a molecular weight of 1 million or more or an organic filler having a three-dimensional crosslinked structure. Such an organic filler may contain one or more selected from an alkyl (meth)acrylate-butadiene-styrene copolymer, an alkyl (meth)acrylate-silicone copolymer, a silicone-(meth)acrylic copolymer, or a composite. The "organic filler having a molecular weight of 1 million or more or an organic filler having a three-dimensional crosslinked structure" refers to an organic filler having poor solubility in a solvent due to its ultra-high molecular weight, or a organic filler having poor solubility in a solvent due to its three-dimensional network structure. As the (E) component, an organic filler having a core-shell structure and different compositions in the core layer and shell layer can also be used. Specific examples of the core-shell organic filler include particles in which an acrylic resin is grafted onto a silicone-acrylic rubber core, and particles in which an acrylic resin is grafted onto an acrylic copolymer.

[0055] The average particle size of the (F) component may be 0.1 to 2 μm. If the average particle size is less than 0.1 μm, it tends to be difficult to obtain the effect of suppressing voids.

[0056] The content of component (F) may be 5 to 20 parts by mass per 100 parts by mass of the adhesive excluding component (F) in order to provide the adhesive layer with void suppression effects during connection and stress relaxation effects after connection.

[0057] Various coupling agents can be added to the adhesive to modify the surface of the filler, improve the interfacial bond between different materials, and increase the adhesive strength. Examples of coupling agents include silane-based, titanium-based, and aluminum-based coupling agents. The coupling agent may be a silane-based coupling agent, which is highly effective.

[0058] Examples of silane coupling agents include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-ureidopropyltriethoxysilane, and 3-ureidopropyltrimethoxysilane. These may be used alone or in combination of two or more.

[0059] An ion trapping agent may be added to the adhesive to adsorb ionic impurities and improve insulation reliability when absorbing moisture. There are no particular limitations on such ion trapping agents. Examples include compounds known as copper damage inhibitors, such as triazine thiol compounds and bisphenol-based reducing agents, which prevent copper from ionizing and dissolving, and inorganic ion adsorbents such as zirconium-based and antimony-bismuth-based magnesium aluminum compounds.

[0060] The adhesive has a linear expansion coefficient of 60×10 at 40 to 100°C after curing to suppress expansion due to temperature changes or heat and moisture absorption after connecting the semiconductor chip and the circuit board and achieve high connection reliability. -6 / ℃ or less, 55×10 -6 / ℃ or less, or 50×10 -6 The linear expansion coefficient of the adhesive layer after curing may be 60×10 -6 When the temperature is 100 to 200° C., it is possible to effectively prevent the electrical connection between the connection portion of the semiconductor chip and the connection portion of the wiring circuit board from being unable to be maintained due to temperature changes after mounting or expansion due to heating and moisture absorption.

[0061] The adhesive sheet 10 may be an anisotropic conductive adhesive film (ACF) in which the adhesive layer 2 contains conductive particles, or it may be a non-conductive adhesive film (NCF) in which the adhesive layer 2 does not contain conductive particles.

[0062] The adhesive layer 2 formed from the adhesive may have a reaction rate of 60% or more, or 70% or more, as measured by DSC, after heating for 10 seconds at 250° C. The reaction rate of the adhesive layer 2 may be less than 10% as measured by DSC after the adhesive sheet is stored at room temperature for 14 days.

[0063] The visible light transmittance of the uncured adhesive layer 2 may be 5% or more, 8% or more, or 10% or more. If the visible light transmittance is less than 5%, alignment tends to be difficult. On the other hand, there is no particular upper limit for the visible light transmittance.

[0064] The visible light transmittance can be measured using a Hitachi U-3310 spectrophotometer. For example, a baseline correction measurement is performed using a 50 μm-thick PET film (Purex, transmittance at 555 nm 86.03%, "Purex" is a registered trademark) manufactured by Toyobo Film Solutions Co., Ltd. as a reference material, and then an adhesive layer 2 is formed on the PET film with a thickness of 25 μm, and the transmittance in the visible light region of 400 to 800 nm is measured. Since the relative wavelength intensity of the halogen light source and light guide used in the flip chip bonder is strongest at 550 to 600 nm, the transmittance of the adhesive layer 2 is compared in this specification using the transmittance at 555 nm.

[0065] The adhesive layer 2 can be formed by dissolving or dispersing the adhesive according to this embodiment described above in a solvent to form a varnish, applying this varnish onto a protective film (hereinafter sometimes referred to as a "first film") 1, and removing the solvent by heating. Thereafter, a support substrate 3 is laminated onto the adhesive layer 2 at room temperature to 80°C, thereby obtaining an adhesive sheet 10 according to this embodiment. The adhesive layer 2 can also be formed by applying the above-mentioned varnish onto the support substrate 3, and removing the solvent by heating.

[0066] For example, plastic films such as polyethylene terephthalate, polytetrafluoroethylene film, polyethylene film, polypropylene film, polymethylpentene film, etc. can be used as the protective film 1. From the viewpoint of peelability, a film made of a fluororesin having low surface energy such as a polytetrafluoroethylene film may be used as the protective film 1.

[0067] In order to improve the releasability of the protective film 1, the surface of the protective film 1 on which the adhesive layer 2 is formed may be treated with a release agent such as a silicone-based release agent, a fluorine-based release agent, or a long-chain alkyl acrylate-based release agent. Commercially available protective films treated with a release agent include, for example, "A-63" (release treatment agent: modified silicone-based) and "A-31" (release treatment agent: Pt-based silicone-based) manufactured by Toyobo Film Solutions Co., Ltd.

[0068] The thickness of the protective film 1 may be 10 to 100 μm, 10 to 75 μm, or 25 to 50 μm. If the thickness is less than 10 μm, the protective film tends to break during coating, and if it exceeds 100 μm, it tends to be less cost-effective.

[0069] Methods for applying the varnish onto the protective film 1 (or supporting substrate 3) include commonly known methods such as knife coating, roll coating, spray coating, gravure coating, bar coating, and curtain coating.

[0070] The thickness of the adhesive layer 2 is not particularly limited, but may be 5 to 200 μm, 7 to 150 μm, or 10 to 100 μm. If the thickness is less than 5 μm, it becomes difficult to ensure sufficient adhesive strength, and the protruding electrodes of the circuit board tend not to be filled. If the thickness is more than 200 μm, it becomes uneconomical and it becomes difficult to meet the demand for miniaturization of semiconductor devices.

[0071] Examples of the supporting substrate 3 include plastic films such as polyethylene terephthalate film, polytetrafluoroethylene film, polyethylene film, polypropylene film, polymethylpentene film, polyvinyl acetate film, polyvinyl chloride film, polyimide film, etc. The supporting substrate 3 may be a mixture of two or more materials selected from the above materials, or a multilayer of the above films.

[0072] The thickness of the support base 3 is not particularly limited, but may be 5 to 250 μm. If the thickness is less than 5 μm, the support base may be cut during grinding (back grinding) of the semiconductor wafer. If the thickness is more than 250 μm, it tends to be uneconomical.

[0073] The supporting substrate 3 may have a minimum light transmittance of 10% or more in the wavelength range of 500 to 800 nm.

[0074] As the supporting substrate 3, a pressure-sensitive adhesive layer laminated on the above-mentioned plastic film (hereinafter sometimes referred to as "second film") can be used.

[0075] Fig. 5 is a schematic cross-sectional view showing another embodiment of the adhesive sheet. The adhesive sheet 11 shown in Fig. 2 includes a support substrate 3 having a plastic film 3b and a pressure-sensitive adhesive layer 3a provided on the plastic film 3b, an adhesive layer 2 provided on the pressure-sensitive adhesive layer 3a and made of the adhesive of this embodiment, and a protective film 1 covering the adhesive layer 2.

[0076] In order to improve the adhesion between the plastic film 3b and the adhesive layer 3a, the surface of the plastic film 3b may be subjected to chemical or physical treatments such as chromate treatment, ozone exposure, flame exposure, high-voltage shock exposure, and ionizing radiation treatment.

[0077] The adhesive layer 3a may have adhesive strength at room temperature and a necessary adhesive strength to an adherend. The adhesive layer 3a may have a property of being cured (i.e., its adhesive strength is reduced) by high-energy rays such as radiation or heat. The adhesive layer 3a may be formed using, for example, acrylic resins, various synthetic rubbers, natural rubbers, and polyimide resins. The thickness of the adhesive layer 3a is usually about 5 to 20 μm.

[0078] The adhesive sheets 10 and 11 can be used to seal at least a part of the electrically connected connections in a semiconductor device in which a plurality of connection parts of a semiconductor chip and a plurality of connection parts of a wiring circuit board are electrically connected to each other, or in a semiconductor device in which a plurality of connection parts of a plurality of semiconductor chips are electrically connected to each other. The adhesive sheets 10 and 11 can also be used as an adhesive in a lamination technique using a silicon through electrode.

[0079] Hereinafter, an example of a method for manufacturing a semiconductor device using the adhesive sheet 10 or 11 will be described. Figs. 6, 7, 8, 9 and 10 are schematic cross-sectional views showing one embodiment of a method for manufacturing a semiconductor device. The method shown in Figs. 6 to 10 includes the steps of preparing a semiconductor wafer 30 having a wafer body A with two main surfaces and a plurality of connection parts 20 provided on one of the main surfaces of the wafer body A, providing an adhesive layer 2 containing an adhesive on the main surface of the wafer body A on the connection part 20 side, thinning the wafer body A by grinding the main surface of the wafer body A opposite to the connection parts 20, and dicing the thinned wafer body A and the adhesive layer 2 to form a semiconductor chip 30' having a chip body A' and a plurality of connection parts 20 and an adhesive layer 2. and heating the semiconductor chip 30', the wiring circuit board 40, and the adhesive layer 2 while interposing the adhesive layer 2 between the semiconductor chip 30' having a plurality of connection portions 20 and the wiring circuit board 40 having a plurality of connection portions 22, so that the connection portions 20 of the semiconductor chip 30' and the connection portions 22 of the wiring circuit board 40 are electrically connected to each other, and a joint 50 is formed in which the electrically connected connection portions 20, 22 are sealed by the hardened adhesive layer 2a.

[0080] 6, the adhesive layer 2 on the support base 3 is attached to the main surface of the wafer body A on which the connection parts 20 are provided, to obtain a laminate in which the support base 3 / adhesive layer 2 / semiconductor wafer 30 are laminated. Some or all of the multiple connection parts 20 provided on the wafer body A may be solder bumps for solder bonding. Some or all of the connection parts 22 of the wiring circuit board 40 may be solder bumps.

[0081] A commercially available film attachment device or laminator can be used to obtain a laminate in which the supporting substrate 3 / adhesive layer 2 / semiconductor wafer 30 are laminated. In order to attach the adhesive layer 2 to the semiconductor wafer 30 without introducing voids, the attachment device is preferably equipped with a heating mechanism and a pressure mechanism, and more preferably equipped with a vacuum suction mechanism. The adhesive layer 2 may be attached to the semiconductor wafer 30 using a roll- or sheet-shaped adhesive sheet 10 processed to fit the outer shape of the semiconductor wafer 30.

[0082] The adhesive layer 2 may be attached to the semiconductor wafer 30 at a temperature at which the adhesive layer 2 softens. The temperature for attachment may be 40 to 80°C, 50 to 80°C, or 60 to 80°C.

[0083] 7, the surface of the wafer body A opposite to the side where the connection portion 20 is provided is ground by a grinder 4 to thin the wafer body A. The thickness of the thinned wafer body A may be, for example, 10 to 300 μm, or 20 to 100 μm.

[0084] A general back grinding (B / G) device can be used to grind the wafer body A. In order to grind the wafer body A uniformly without unevenness in thickness in the B / G process, the adhesive layer 2 may be attached to the semiconductor wafer 30 uniformly without involving voids.

[0085] As shown in (a) of FIG. 8, a dicing tape 5 is attached to the semiconductor wafer 30 of the laminate, and the dicing tape 5 is placed in a predetermined device to peel off the support base 3. At this time, when the support base 3 has an adhesive layer 3a as in the adhesive sheet 11 shown in FIG. 5, and the adhesive layer 3a is radiation curable, the adhesive layer 3a can be cured by irradiating radiation from the support base 3 side, thereby reducing the adhesive force between the adhesive layer 2 and the support base 3. Examples of the radiation used here include ultraviolet rays, electron beams, and infrared rays. This allows the support base 3 to be easily peeled off. After the support base 3 is peeled off, the wafer body A and adhesive layer 2 of the semiconductor wafer 30 are diced by a dicing saw 6, as shown in (b) of FIG. 8. In this way, the wafer body A is divided into a plurality of chip bodies A', and the adhesive layer 2 is divided into a plurality of parts on the chip body A'. By dicing, a semiconductor chip 30' having a chip body A' and a plurality of connection parts 20 is formed.

[0086] 9, the dicing tape 5 is expanded to separate the semiconductor chips 30' from each other, and the semiconductor chip 30' pushed up by the needle from the dicing tape 5 side and the adhesive-attached semiconductor chip 35 consisting of the adhesive layer 2 are sucked and picked up by the suction collet 7. The adhesive-attached semiconductor chip 35 may be collected in a tray, or may be mounted directly on the wiring circuit board 40 by a flip chip bonder.

[0087] The operation of attaching the dicing tape 5 to the ground wafer body A can be performed in the same process as the fixing to the dicing frame using a general wafer mounter. The dicing tape 5 can be a commercially available dicing tape, and may be either a UV-curable type or a pressure-sensitive type.

[0088] As shown in FIG. 10, the connection portion 20 of the semiconductor chip 30' and the connection portion 22 of the wiring circuit board 40 are aligned, and the adhesive-attached semiconductor chip 35 and the wiring circuit board 40 are thermocompression-bonded. This thermocompression bonding forms a bonded body 50 consisting of the wiring circuit board 40, the semiconductor chip 30', and the hardened adhesive layer 2a. The wiring circuit board 40 has a base material 8 and a plurality of connection portions 22 provided on the base material 8. The connection portions 20 and the connection portions 22 are electrically and mechanically connected by solder bonding or the like. A hardened adhesive layer 2a that seals the connection portions 20, 22 is formed between the semiconductor chip 30' and the wiring circuit board 40. The step of forming the bonded body 50 may include forming a provisionally bonded body by thermocompression-bonding the adhesive-attached semiconductor chip 35 and the wiring circuit board 40 at a temperature lower than the melting points of the connection portions 20, 22, and forming the bonded body 50 by heating and pressurizing the provisionally bonded body at a temperature at which at least one of the connection portions 20 and 22 melts.

[0089] From the viewpoint of solder bonding, the temperature during thermocompression bonding may be 200° C. or higher, or 220 to 260° C. The thermocompression bonding time may be 1 to 20 seconds. The thermocompression bonding pressure may be 0.1 to 5 MPa.

[0090] When mounting on the wiring circuit board 40 using a flip chip bonder, the connecting parts 20, 22 can be aligned by referring to alignment marks formed on the circuit surface of the chip body A'.

[0091] Through the above steps, a semiconductor device is obtained that includes a bonded body 50 having a wiring circuit board 40, a semiconductor chip 30' mounted on the wiring circuit board 40, and an adhesive layer 2a interposed between them and sealing the connection portions 20, 22.

[0092] Fig. 11 is a schematic cross-sectional view showing another embodiment of a method for manufacturing a semiconductor device. The method shown in Fig. 11 includes a step of heating the semiconductor chip 30', the semiconductor wafer 30, and the adhesive layer 2 while interposing an adhesive layer 2 made of an adhesive between the semiconductor chip 30' having a plurality of connecting parts 20 and the semiconductor wafer 30 having a plurality of connecting parts 23, so that the connecting parts 20 of the semiconductor chip 30' and the connecting parts 23 of the semiconductor wafer A are electrically connected to each other, and the electrically connected connecting parts 22, 23 are sealed by the adhesive layer 2a made of a hardened adhesive to form a bonded body 50. More specifically, the process of forming the bonded body 50 includes placing the semiconductor wafer 30 on a stage 60 as shown in (a) of FIG. 11, forming a temporary pressure-bonded body 55 which is a laminate composed of the semiconductor wafer 30, the adhesive layer 2 and the semiconductor chip 30' as shown in (b) of FIG. 11, heating and pressurizing the temporary pressure-bonded body 55 to a temperature at which at least one of the connection portions 20 and 23 melts as shown in (c) of FIG. 11 to form a bonded body 50 in which the connection portions 20 and 23 are electrically connected as shown in (d) of FIG. 11, and further heating and pressurizing the bonded body 50 in a pressure oven 90 as shown in (e) of FIG. 11.

[0093] The connection portion 20 of the semiconductor chip 30' has a pillar or bump 20a provided on the chip body A' and a solder 20b provided on the pillar or bump 20a. The semiconductor wafer 30 has a wafer body A, wiring 15 provided on the wafer body A, a connection portion 24 provided on the wiring 15, and a passivation film 16 provided on the wafer body A and covering the wiring 15.

[0094] The temporary compression bonded body 55 is formed by thermocompression bonding the adhesive-attached semiconductor chip 35 to the semiconductor wafer 30 by a compression bonding tool 70 on a heated stage 60. The heating temperature of the stage 60 is lower than the melting point of the connection parts 20 (particularly the solder 20b) and the melting point of the connection parts 23, and may be, for example, 60 to 150°C, or 70 to 100°C. The temperature of the compression bonding tool 70 may be, for example, 80 to 350°C, or 100 to 170°C. The time of thermocompression bonding to form the temporary compression bonded body 55 may be, for example, 5 seconds or less, 3 seconds or less, or 2 seconds or less.

[0095] The bonded body 50 is formed by applying pressure to the pre-bonded body 55 on the heated stage 60 while heating it to at least one of the melting point of the connection portion 20 (particularly the solder 20b) or the melting point of the connection portion 23 using the bonding tool 80. The temperature of the bonding tool 80 may be, for example, 180° C. or more, 220° C. or more, or 250° C. or more, and may be 350° C. or less, 320° C. or less, or 300° C. or less. The heating temperature of the stage 60 during the thermocompression bonding to form the bonded body 50 may be 60 to 150° C., or 70 to 100° C. The time of thermocompression bonding by the bonding tool 80 to form the bonded body 50 may be, for example, 5 seconds or less, 3 seconds or less, or 2 seconds or less.

[0096] The adhesive layer 2 is cured sufficiently by heating and pressing in the pressure oven 90. However, the adhesive layer 2 may be partially cured during the heating and pressing process for forming the bonded body 60. The heating temperature in the pressure oven 90 may be a temperature that is lower than the melting point of the connecting parts 20, 24 and at which the adhesive layer 2 is cured, for example, 170 to 200°C.

[0097] A bonded body 50 having a plurality of semiconductor chips 30' may be formed by sequentially mounting a plurality of semiconductor chips 30' on one semiconductor wafer 30 via an adhesive layer 2, and then the bonded body 50 may be heated and pressurized in a pressure oven 90. In this case, the adhesive layer 2 between the semiconductor chips 30' initially placed on the semiconductor wafer 30 and the semiconductor wafer 30 continues to be subjected to a thermal history by the stage 60 until the mounting of all the semiconductor chips 30' is completed. Even after being subjected to a long period of thermal history, the adhesive layer 2 including the adhesive according to the above-mentioned embodiment can provide the bonded body 50 with high reliability.

[0098] The manufacturing method according to this embodiment may include a step of electrically connecting the connection parts of a plurality of semiconductor chips to each other by interposing an adhesive layer containing an adhesive between a plurality of semiconductor chips having a plurality of connection parts, and heating the connection parts of the semiconductor chips and the adhesive layer, and sealing at least a portion of the connection parts electrically connected to each other with the hardened adhesive.

[0099] The adhesive according to this embodiment and the adhesive layer formed therefrom have excellent embedding properties and adhesive strength after curing, and can remove the oxide film formed on the solder surface even in a short time of soldering, thereby improving solder wettability. Therefore, the bonded body 50 can be excellent in reflow crack resistance and connection reliability, with the generation of voids sufficiently suppressed, the connection parts being well bonded, and the semiconductor chip 30' and the wiring circuit board 40, the semiconductor wafer 30, or another semiconductor chip being bonded with sufficient adhesive strength. EXAMPLES

[0100] The present invention will be described in more detail below with reference to examples and comparative examples, although the present invention is not limited to these examples.

[0101] 1.Raw materials The compounds used in the examples and comparative examples are as follows. (A) Thermosetting resin EP1032: Triphenolmethane skeleton-containing multifunctional solid epoxy resin (manufactured by Japan Epoxy Resins Co., Ltd., product name "EP1032H60") YL983: Bisphenol F type liquid epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., product name "YL983U") YL7175: Flexible epoxy resin (product name "YL7175" manufactured by Japan Epoxy Resin Co., Ltd.) (B) Imidazole-based curing agent ·2MAOK: 2,4-Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct (manufactured by Shikoku Chemical Industry Co., Ltd., product name "2MAOK-PW") 2PHZ: 2-Phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd., product name "2PHZ-PW") (C)Organic acid Glutaric acid (Tokyo Chemical Industry Co., Ltd., melting point 98°C) Diphenylacetic acid (Tokyo Chemical Industry Co., Ltd., melting point 147°C) Benzilic acid (Tokyo Chemical Industry Co., Ltd., melting point 149°C) (D) Thermoplastic resin FX293: Phenoxy resin (product name "FX293" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) (E) Inorganic filler KE180G-HLA: Silica filler (manufactured by Admatechs Co., Ltd.) (F) Organic filler EXL-2655: Core-shell type organic particles (manufactured by Rohm and Haas Japan Co., Ltd., product name "EXL-2655")

[0102] 2. Preparation of Adhesive Sheets Example 1 A mixture of 45 parts by mass of EP1032, 15 parts by mass of YL983, 5 parts by mass of YL7175, 3 parts by mass of 2PHZ, 2 parts by mass of glutaric acid, 71.5 parts by mass of KE180G-HLA, 10 parts by mass of EXL-2655, and methyl ethyl ketone with a solid concentration of 63% by mass, beads with a diameter of 0.8 mm, and beads with a diameter of 2.0 mm were stirred for 30 minutes in a bead mill (Fritsch Japan Co., Ltd., planetary fine grinder P-7). Then, 20 parts by mass of FX293 were added, and the mixture and beads were stirred again for 30 minutes in a bead mill. The beads were removed by filtration to obtain a resin varnish.

[0103] The obtained resin varnish was applied to a plastic film (manufactured by Teijin DuPont Films Co., Ltd., product name "Purex A53") as a supporting substrate using a small precision coating device (manufactured by Yasui Seiki Co., Ltd.), and the coating film was dried (70°C / 10 min) in a clean oven (manufactured by ESPEC) to obtain an adhesive sheet having a supporting substrate and an adhesive layer with a thickness of 0.020 mm. Two adhesive sheets were bonded together to form an adhesive layer with a thickness of 0.040 mm, which was used to evaluate the connection reliability after heat treatment.

[0104] (Examples 2 and 3, Comparative Examples 1 and 2) Adhesive sheets of Examples 2 and 3 and Comparative Examples 1 and 2 were produced in the same manner as in Example 1, except that the types and compounding ratios of materials were changed as shown in Table 1.

[0105] 3.DSC measurement A 10 mg sample taken from the adhesive layer of each adhesive sheet was subjected to differential scanning calorimetry (DSC) using a differential scanning calorimeter (Thermo plus DSC8235E, manufactured by Rigaku Corporation) under conditions of a nitrogen atmosphere, a heating rate of 10°C / min, and a measurement temperature range of 30 to 300°C. The obtained DSC curve was analyzed in the temperature range of 60 to 280°C by the partial area method, and the heat generation amount (unit: J / g) in the range of 60 to 155°C was calculated by specifying the baseline. The analysis was performed in the temperature range of 60 to 280°C by the total area (JIS method) analysis method, and the intersection point between the extension line of the baseline in the DSC curve and the tangent line of the DSC curve at the point of maximum gradient of the exothermic peak was calculated, and the temperature at the intersection point was taken as the onset temperature (unit: °C).

[0106] 4. Evaluation of connection reliability after thermal history Each adhesive sheet was cut into a size of 8 mm in length and 8 mm in width, and the adhesive layer was attached to a wiring circuit board (glass epoxy base material: 420 μm thick, copper wiring: 9 μm thick). The adhesive layer attached to the wiring circuit board was given a thermal history by heat treatment at 70 ° C for 5 hours. Then, a semiconductor chip with solder bumps (chip size: length 7.3 mm × width 7.3 mm × thickness 0.15 mm, total height of copper pillar and solder bump: about 40 μm, number of solder bumps: 328) was mounted on the wiring circuit board using a flip mounting device "FCB3" (manufactured by Panasonic Corporation, product name) with the adhesive layer interposed (mounting conditions: pressure head temperature 320 ° C, pressure bonding time 6 seconds, pressure bonding pressure 15 N). As a result, a semiconductor device was produced in which the wiring circuit board and the semiconductor chip with solder bumps were connected in a daisy chain, and the connection part (copper wiring and solder bumps) was sealed with the hardened adhesive.

[0107] The connection resistance of the obtained semiconductor device was measured using a multimeter (manufactured by ADVANTEST Corporation, product name "R6871E"). Based on the connection resistance value, the initial conduction after mounting was evaluated according to the following criteria. "A" means that the connection reliability is good. A: 10.0~13.5Ω B: 13.5~20Ω C: Resistance value is greater than 20 Ω, less than 10.0 Ω, or not displayed due to poor connection

[0108] [Table 1]

[0109] The evaluation results are shown in Table 1. It was confirmed that the adhesives of Examples 1 to 3 suppressed the initiation of curing during exposure to heat history and ensured fluidity, thereby maintaining good connection reliability even after exposure to heat history. [Explanation of symbols]

[0110] 1...protective film, 2...adhesive layer, 2a...cured adhesive, 3...supporting substrate, 3a...pressure-sensitive adhesive layer, 3b...plastic film, 4...grinder, 5...dicing tape, 6...dicing saw, 7...suction collet, 8...substrate, 10, 11...adhesive sheet, 20...connection portion, 22...connection portion, 30...semiconductor wafer, 30'...semiconductor chip, 35...semiconductor chip with adhesive, 40...wiring circuit board, 50...bonded body, A...wafer body, A'...chip body, P...heat generation peak, T...onset temperature.

Claims

1. A semiconductor adhesive comprising a thermosetting resin, a curing agent, and a flux compound having an acid group, the thermosetting resin is at least one selected from the group consisting of epoxy resins, unsaturated polyester resins, melamine resins, urea resins, diallyl phthalate resins, bismaleimide resins, triazine resins, polyurethane resins, phenolic resins, cyanoacrylate resins, polyisocyanate resins, furan resins, resorcinol resins, xylene resins, benzoguanamine resins, silicone resins, siloxane-modified epoxy resins, and siloxane-modified polyamideimide resins; the heat generation amount from 60 to 155°C in a DSC curve obtained by differential scanning calorimetry in which the adhesive for semiconductors is heated at a temperature increase rate of 10°C / min is 20 J / g or less; In the DSC curve, the onset temperature of the exothermic peak due to the curing reaction is 150° C. or higher. Adhesive for semiconductors.

2. The adhesive for semiconductors according to claim 1 , wherein the flux compound is an organic acid having a carboxyl group.

3. 3. The adhesive for semiconductors according to claim 1, wherein the melting point of the flux compound is 50 to 200°C.

4. The semiconductor adhesive according to any one of claims 1 to 3, wherein the curing agent comprises an imidazole-based curing agent.

5. The adhesive for a semiconductor according to any one of claims 1 to 4, further comprising a thermoplastic resin.

6. The semiconductor adhesive according to any one of claims 1 to 5, which is used to seal at least a portion of the electrically connected connection portions in a semiconductor device in which a plurality of connection portions of a semiconductor chip and a plurality of connection portions of a wiring circuit board are electrically connected to each other, or in a semiconductor device in which a plurality of connection portions of a plurality of semiconductor chips are electrically connected to each other.

7. The semiconductor adhesive according to claim 6 , wherein at least a portion of the plurality of connection portions of the semiconductor chip include solder bumps.

8. A semiconductor adhesive sheet comprising a supporting substrate and an adhesive layer provided on the supporting substrate and comprising the semiconductor adhesive according to any one of claims 1 to 7.

9. 9. The adhesive sheet for a semiconductor according to claim 8, wherein the supporting substrate has a plastic film and a pressure-sensitive adhesive layer provided on the plastic film, and the adhesive layer is provided on the pressure-sensitive adhesive layer.

10. a step of forming a bonded body in which an adhesive is interposed between a semiconductor chip having a plurality of connection portions and a wiring circuit board having a plurality of connection portions, and the semiconductor chip, the wiring circuit board, and the adhesive are heated and pressurized, so that the connection portions of the semiconductor chip and the connection portions of the wiring circuit board are electrically connected to each other, and at least a portion of the connection portions electrically connected to each other are sealed by the hardened adhesive; a step of forming a bonded body in which a plurality of semiconductor chips each having a plurality of connection parts are electrically connected to each other by heating and pressurizing the semiconductor chips and the adhesive while an adhesive is interposed between the semiconductor chips, and at least a portion of the connection parts electrically connected to each other are sealed by the hardened adhesive; A process for forming a bonded body, in which an adhesive is interposed between a semiconductor chip having a plurality of connection parts and a semiconductor wafer having a plurality of connection parts, and the semiconductor chip, the semiconductor wafer, and the adhesive are heated, so that the connection parts of the semiconductor chip and the connection parts of the semiconductor wafer are electrically connected to each other, and at least a part of the connection parts electrically connected to each other is sealed by the hardened adhesive. The method includes at least one step selected from The adhesive is a semiconductor adhesive according to any one of claims 1 to 5. A method for manufacturing a semiconductor device.

11. The method comprises: A step of preparing a semiconductor wafer having a wafer body having two main surfaces and a plurality of the connection portions provided on one of the main surfaces of the wafer body; providing an adhesive layer containing the adhesive on a main surface of the wafer body on the connection portion side; a step of thinning the wafer body by grinding a main surface of the wafer body opposite to the connection portion; forming an adhesive-attached semiconductor chip having the semiconductor chip and the adhesive layer by dicing the thinned wafer body and the adhesive layer; Further comprising: The method of claim 10.

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