Method for manufacturing semiconductor device, substrate, and semiconductor element

Abstract

A method for manufacturing a semiconductor device comprising: stacking a semiconductor element, which is provided with a protruding electrode having a solder layer at a distal end portion thereof, on a substrate, which is provided with an electrode pad, which has a metal protruding portion on a surface thereof, on a surface on a side opposing a surface of the semiconductor element on a side provided with the protruding electrode, in a state in which a resin film is interposed between the semiconductor element and the substrate such that the solder layer in the semiconductor element and the distal end of the metal protruding portion in the substrate are brought in contact each other; and melting the solder layer by heating to connect the substrate and the semiconductor element to each other.

Description

Semiconductor device manufacturing method, substrate and semiconductor element

[0001] The present disclosure relates to a method for manufacturing a semiconductor device, a substrate, and a semiconductor element.

[0002] Conventionally, wire bonding connection methods using thin metal wires such as gold wires have been known as a method for mounting semiconductor elements on a substrate. Meanwhile, in order to meet demands for smaller, thinner, more functional, more integrated, and faster semiconductor devices, flip-chip connection methods (FC connection methods) that connect semiconductor elements to electrodes on a substrate via protruding electrodes called bumps provided on the semiconductor elements are becoming more widespread. The FC connection method is widely used in BGA (Ball Grid Array), CSP (Chip Size Package), and the like to connect semiconductor elements to a substrate. The COB (Chip On Board) type connection method also falls under the category of FC connection methods. The FC connection method is also widely used in COC (Chip On Chip) type connection methods for connecting semiconductor elements (see, for example, Patent Document 1).

[0003] In order to meet the demand for further miniaturization, thinning, and high performance of semiconductor devices, stacked and multi-tiered chip-stacked packages and POP (Package On Package) using the above-mentioned connection methods have become widespread. Furthermore, the TSV (Through-Silicon Via) method has also begun to gain widespread popularity. Such stacking and multi-tiering technologies arrange semiconductor elements, etc., three-dimensionally, thereby enabling a smaller package area compared to methods that arrange semiconductor elements, etc., two-dimensionally. In particular, TSV technology is effective in improving semiconductor performance, reducing noise, reducing packaging area, and saving power, and is attracting attention as a next-generation semiconductor wiring technology.

[0004] Furthermore, when manufacturing a semiconductor device using the FC connection method, thermal stress resulting from the difference in thermal expansion coefficient between the semiconductor element and the substrate or between semiconductor elements may concentrate at the connection, causing poor connection. To prevent poor connection due to the difference in thermal expansion coefficient, it is effective to seal the gap between two adjacent circuit components (semiconductor element, substrate, etc.) with an adhesive composition. In particular, since components with different thermal expansion coefficients are often used for the semiconductor element and the substrate, it is necessary to seal the semiconductor device with an adhesive composition to improve thermal shock resistance.

[0005] FC connection methods using adhesive compositions can be broadly divided into capillary-flow methods and pre-applied methods (see, for example, Patent Documents 2 to 6). The capillary-flow method is a method in which, after connecting a semiconductor element and a substrate, a liquid adhesive composition is injected into the gap between the semiconductor element and the substrate by capillary action. The pre-applied method is a method in which, before connecting the semiconductor element and the substrate, a paste-like or film-like adhesive composition is supplied onto the semiconductor element or the substrate, and then the semiconductor element and the substrate are connected.

[0006] Japanese Patent Application Laid-Open No. 2008-294382 Japanese Patent Application Laid-Open No. 2001-223227 Japanese Patent Application Laid-Open No. 2002-283098 Japanese Patent Application Laid-Open No. 2005-272547 Japanese Patent Application Laid-Open No. 2006-169407 Japanese Patent Application Laid-Open No. 2006-188573

[0007] Generally, in the manufacture of semiconductor devices using a pre-applied method using an adhesive composition (underfill material), the underfill material is applied between the semiconductor element and the substrate and then heat-cured. Currently, with this method, the underfill material is applied between the semiconductor element and the substrate and then heat-cured for each semiconductor device. Therefore, the current manufacturing of semiconductor devices using pre-applied underfill materials has poor production efficiency, making improving production efficiency an important challenge. In particular, when a resin film is used as the underfill material, the resin film can become trapped between the tip of the protruding electrode and the electrode on the substrate, resulting in poor connection between the semiconductor element and the substrate. Furthermore, in order to prevent the resin film from becoming trapped, the pressure applied when bonding the semiconductor element and the substrate tends to be high, and the pressure application time also tends to be long.

[0008] Furthermore, with the recent trend toward miniaturization of semiconductor devices, the pitch and size of protruding electrodes are becoming increasingly narrow. Therefore, when a semiconductor element is temporarily mounted on a substrate and then soldered by reflow, the vibrations during the reflow process and the handling of the substrate can cause misalignment of the connection. When semiconductor elements are stacked using the TSV method, the semiconductor elements are very unstable after temporary mounting, so misalignment of the connection tends to occur easily.

[0009] The present disclosure has been made in consideration of the above-mentioned conventional circumstances, and aims to provide a method for manufacturing a semiconductor device that can suppress biting of a resin film when connecting a semiconductor element to a substrate or when connecting semiconductor elements together, as well as a substrate and a semiconductor element that can be applied to this manufacturing method.

[0010] Specific means for achieving the above object are as follows: <1> A method for manufacturing a semiconductor device, comprising: stacking a semiconductor element on a substrate, the semiconductor element having protruding electrodes with solder layers at their tips, and a substrate having electrode pads with metal protrusions on a surface of the semiconductor element opposite to the surface having the protruding electrodes, with a resin film interposed between the semiconductor element and the substrate, by bringing the solder layer of the semiconductor element into contact with the tips of the metal protrusions of the substrate; and melting the solder layer by heating to connect the substrate and the semiconductor element. <2> The method for manufacturing a semiconductor element according to <1>, wherein the semiconductor element stacked on the substrate has an electrode pad having a metal convex portion on a surface opposite to the surface having the protruding electrode, and a plurality of semiconductor elements are stacked on the semiconductor element stacked on the substrate, the semiconductor elements having protruding electrodes with solder layers on their tips on one side and electrode pads having metal convex portions on their surfaces on the other side, the plurality of semiconductor elements being stacked on the semiconductor element stacked on the substrate by repeatedly stacking the semiconductor elements by contacting the solder layer of one semiconductor element with the tips of the metal convex portions of the other semiconductor elements with the resin film interposed between the one semiconductor element and the other semiconductor element, and the plurality of semiconductor elements are collectively connected to the substrate by melting the solder layer by heating. <3> The method for manufacturing a semiconductor element according to <1> or <2>, wherein the solder layer is brought into contact with the tips of the metal convex portions with the resin film interposed therebetween while heating under conditions equal to or lower than the melting temperature of the solder constituting the solder layer. <4> The method for manufacturing a semiconductor device according to any one of <1> to <3>, wherein the bump electrodes have pillars and the solder layers provided on the tips of the pillars, and the sum of the average height of the pillars and the average height of the metal convex portions is smaller than the average thickness of the resin film. <5> The method for manufacturing a semiconductor device according to <4>, wherein the average height of the pillars is 20 μm or less. <6> The method for manufacturing a semiconductor device according to any one of <1> to <5>, wherein the tips of the metal convex portions have acute angles. <7> The method for manufacturing a semiconductor device according to any one of <1> to <6>, wherein the resin film contains a thermosetting resin.<8> The method for manufacturing a semiconductor device according to <7>, wherein the thermosetting resin contains at least one selected from the group consisting of epoxy resin, polyamic acid, and polyhydroxyamide. <9> The method for manufacturing a semiconductor device according to any one of <1> to <6>, wherein the resin film contains a thermoplastic resin. <10> The method for manufacturing a semiconductor device according to <9>, wherein the thermoplastic resin contains at least one selected from the group consisting of polyimide, polyamide, polycarbonate, polyacetal, polyphenylene ether, polybutylene terephthalate, polytetrafluoroethylene, polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, polyamideimide, polyetherimide, polyetheretherketone, acrylic resin, phenoxy resin, polyester, polyurethane, polybenzoxazole, and polybutadiene. <11> The method for manufacturing a semiconductor device according to any one of <1> to <10>, wherein the resin film contains an inorganic filler. <12> The method for manufacturing a semiconductor device according to <11>, wherein the content of the inorganic filler is 10% by mass to 80% by mass based on the total amount of the resin film. <13> The method for manufacturing a semiconductor device according to any one of <1> to <12>, wherein the resin film has a viscosity of 500 mPa·s to 4000 mPa·s at 130° C. <14> A substrate comprising electrode pads having metal convex portions with acute tips on their surfaces. <15> A semiconductor element comprising electrode pads having metal convex portions with acute tips on their surfaces.

[0011] According to the present disclosure, it is possible to provide a method for manufacturing a semiconductor device that can suppress biting of a resin film when connecting a semiconductor element to a substrate or connecting semiconductor elements together, as well as a substrate and a semiconductor element that can be applied to this manufacturing method.

[0012] FIG. 1 is a diagram for explaining a method for manufacturing a semiconductor device according to a first embodiment; FIG. 2 is a cross-sectional view showing a cross section of a modified example of the substrate 10 according to the first embodiment; FIG. 3 is a diagram for explaining a method for manufacturing a semiconductor device according to the first embodiment; FIG. 4 is a diagram for explaining a method for manufacturing a semiconductor device according to a second embodiment; FIG. 5 is a diagram for explaining a method for manufacturing a semiconductor device according to the second embodiment; FIG. 6 is a diagram for explaining a method for manufacturing a semiconductor device according to the second embodiment.

[0013] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure.

[0014] In the present disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved. In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, particles corresponding to each component may include multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified. In the present disclosure, the terms "layer" or "film" include cases where the layer or film is formed over the entire area when the area where the layer or film is present is observed, as well as cases where the layer or film is formed only over a portion of the area. In the present disclosure, the term "laminate" refers to stacking layers, and two or more layers may be bonded together, or two or more layers may be detachable. In the present disclosure, the average thickness of a layer or film is determined by measuring the thickness at five points on the target layer or film and calculating the arithmetic mean value. The thickness of a layer or film can be measured using a micrometer or the like. In the present disclosure, if the thickness of a layer or film can be measured directly, it is measured using a micrometer. On the other hand, when measuring the thickness of a single layer or the total thickness of multiple layers, it may be measured by observing the cross section of the target using an electron microscope.

[0015] <Method for Manufacturing a Semiconductor Device> The method for manufacturing a semiconductor device disclosed herein includes the steps of: stacking a semiconductor element on a substrate, the semiconductor element having protruding electrodes with solder layers at their tips, and the substrate having electrode pads with metal protrusions on the surface opposite the surface of the semiconductor element that has the protruding electrodes, with a resin film interposed between the semiconductor element and the substrate, by contacting the solder layer on the semiconductor element with the tips of the metal protrusions on the substrate (hereinafter sometimes referred to as the contacting step); and melting the solder layer by heating to connect the substrate and the semiconductor element (hereinafter sometimes referred to as the connecting step). The method for manufacturing a semiconductor device disclosed herein can prevent the resin film from getting caught when connecting a semiconductor element to a substrate or between semiconductor elements. The reason for this is unclear, but is presumed to be as follows. In the method for manufacturing a semiconductor device disclosed herein, the contacting step uses a semiconductor element having protruding electrodes with solder layers at their tips and a substrate having electrode pads with metal protrusions on their surfaces. Because metal protrusions are present on the surface of the electrode pads on the substrate, when the solder layer provided on the tip of the protruding electrode of the semiconductor element is brought into contact with the tip of the metal protrusion on the substrate, the tip of the metal protrusion pushes aside the resin film and comes into contact with the solder layer. Therefore, it is presumed that the resin film is less likely to be trapped between the protruding electrode of the semiconductor element and the electrode pad of the substrate. For the same reason, it is presumed that the resin film is less likely to be trapped between the protruding electrode and the electrode pad when connecting semiconductor elements. By making it less likely that the resin film is trapped between the protruding electrode and the electrode pad, the occurrence of connection defects tends to be more easily suppressed.

[0016] In the present disclosure, "connection" refers to electrical connection between a semiconductor element and a substrate or between semiconductor elements via protruding electrodes and electrode pads.

[0017] An embodiment of a method for manufacturing a semiconductor device according to the present disclosure will be described in detail below with reference to the drawings. In the following description, identical or equivalent parts will be designated by the same reference numerals, and duplicated explanations will be omitted. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios in the drawings are not limited to those shown.

[0018] First Embodiment A method for manufacturing a semiconductor device according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 4. In the method for manufacturing a semiconductor device according to the first embodiment, a semiconductor element is stacked in the thickness direction of a substrate. FIG. 1 is a cross-sectional view showing a substrate 10 and a semiconductor element 20 used in the method for manufacturing a semiconductor device according to the first embodiment. FIG. 1 illustrates the semiconductor element 20 and the substrate 10 before they are connected. The semiconductor element 20 has a semiconductor element body 21 and a plurality of protruding electrodes 26 each including a pillar 22 disposed on one surface of the semiconductor element body 21 and a solder layer 24 provided at the tip of the pillar 22. The substrate 10 also has a substrate body 11 and a plurality of electrode pads 16 each including an electrode pad body 12 disposed on a surface of the substrate body 11 opposite the surface on which the protruding electrodes 26 of the semiconductor element 20 are provided, and a metal protrusion 14 provided on the surface of the electrode pad body 12. Furthermore, a resin film 30 is disposed on one side of the semiconductor element 20 (i.e., the side facing the substrate 10), so that the resin film 30 is interposed between the semiconductor element 20 and the substrate 10.

[0019] The type of semiconductor element body 21 is not particularly limited, and may be an elemental semiconductor composed of the same type of element such as silicon or germanium, or a compound semiconductor such as gallium arsenide or indium phosphide. Examples include a chip (die) itself that is not packaged in a resin or the like, or a semiconductor package called a CSP, BGA, or the like that is packaged in a resin or the like.

[0020] The protruding electrodes 26 are not particularly limited as long as they have the solder layers 24 at their tip portions. In the first embodiment, the protruding electrodes 26 are formed by combining the pillars 22 with the solder layers 24 provided at the tip portions of the pillars 22, but the configuration of the protruding electrodes 26 is not limited to this.

[0021] The spacing between the bump electrodes 26 is not particularly limited, but is preferably 1 μm to 100 μm, more preferably 10 μm to 70 μm, and even more preferably 30 μm to 50 μm. The thickness of the solder layer 24 is not particularly limited, but is preferably 0.1 μm to 50 μm, more preferably 1 μm to 30 μm, and even more preferably 5 μm to 20 μm. If the thickness of the solder layer 24 is 0.1 μm or more, the penetration amount of the metal protrusions 14 into the solder layer 24 can be sufficiently ensured, and the temporary fixing force is less likely to be weak. Therefore, misalignment of the semiconductor element 20 in subsequent processes tends to be less likely. If the thickness of the solder layer 24 is 50 μm or less, the processing time required to melt the solder layer 24 by heating and connect the substrate 10 and the semiconductor element 20 tends to be less long. Furthermore, electrical short circuits between adjacent electrodes tend to be less likely to occur when connecting the substrate 10 and the semiconductor element 20. The average height of the pillars 22 is not particularly limited, and is preferably 20 μm or less, more preferably 0.1 μm to 20 μm, and even more preferably 2 μm to 10 μm. Setting the average height of the pillars 22 to 20 μm or less tends to reduce the overall height of the semiconductor device when the semiconductor elements 20 are stacked. Note that setting the average height of the pillars 22 to 20 μm or less tends to result in relatively large variations in the height of the individual pillars 22. In the semiconductor device manufacturing method disclosed herein, the solder layer 24 provided on the tip of the bump electrode 26 is brought into contact with the tip of the metal convex portion 14, and therefore the tip of the metal convex portion 14 penetrates the solder layer 24, thereby absorbing variations in the height of the individual pillars 22 and tending to further improve connection reliability.

[0022] When the bump electrode 26 has a pillar 22 and a solder layer 24 provided on the tip of the pillar 22, the pillar 22 may have a metal layer mainly composed of gold, silver, copper, tin, nickel, or the like, formed by plating, for example. The metal layer constituting the pillar 22 may contain a single component or multiple components. The metal layer may have a single-layer structure or a multi-layer structure in which multiple metal layers are stacked. Copper is preferably used as the material for the pillar 22 because it has low electrical resistance and relatively high corrosion resistance.

[0023] Examples of solder materials that can be used to form the solder layer 24 include tin-silver solder, tin-lead solder, tin-bismuth solder, tin-copper solder, gold-copper solder, and tin-silver-copper solder. From the perspectives of environmental and safety concerns, lead-free solders such as gold-copper solder, tin-copper solder, tin-bismuth solder, tin-silver solder, and tin-silver-copper solder are preferred. When forming the solder layer 24 on the copper pillar 22, a nickel layer may be formed between the copper pillar 22 and the solder layer 24 to suppress diffusion between metal components, thereby improving connection reliability. Furthermore, to facilitate penetration of the metal protrusions 14 of the electrode pad 16 into the solder layer 24, the solder layer 24 may not be subjected to a heat treatment after being formed on the tip of the pillar 22 by plating, printing, or the like.

[0024] The type of substrate body 11 is not particularly limited, and examples thereof include a wiring board in which conductive wiring including connection electrodes is formed on an organic substrate containing a fiber substrate such as FR4 or FR5, a build-up organic substrate not containing a fiber substrate, an organic film such as polyimide or polyester, or a substrate containing an inorganic material such as alumina, glass, or silicon. Circuits, substrate electrodes, etc. may be formed on the substrate body 11 by a semi-additive method, a subtractive method, etc. The substrate body 11 may be silicon (Si). Silicon (Si) substrates are not limited in size, thickness, etc. Examples of silicon (Si) substrates include wafers on whose surfaces conductive wiring including connection electrodes is formed. Furthermore, silicon (Si) substrates may have wiring, transistors, other electronic elements, through-silicon vias (TSVs), etc. formed thereon.

[0025] The electrode pad body 12 may be a conductive wiring formed on the surface of the substrate body 11 by a method such as a semi-additive method or a subtractive method.

[0026] The metal protrusions 14 may be formed on the surface of the electrode pad body 12 using photolithography. When the metal protrusions 14 are formed on the surface of the electrode pad body 12 using photolithography, they can be formed through a process of applying a photosensitive photoresist to the surface of the electrode pad body 12, leaving a seed layer, exposing it to light, developing it, plating it, peeling off the photoresist, and etching the seed layer. The method for forming the metal protrusions 14 on the surface of the electrode pad body 12 is not limited to the above method. In addition to the method of forming the metal protrusions 14 using photolithography, other methods that can be used include welding a metal wire such as gold or copper to the electrode pad using a ball bonder, forming it into a columnar shape, and cutting it to a specific length, forming it using a 3D printer, and forming it by cutting.

[0027] The material of the metal protrusions 14 is not particularly limited, and various metals such as copper and nickel may be used. When copper is used as the material of the metal protrusions 14, the heat dissipation effect at the connection between the substrate 10 and the semiconductor element 20 tends to be improved and the connection resistance tends to be lower. Furthermore, to ensure a reliable connection between the substrate 10 and the semiconductor element 20, the surfaces of the metal protrusions 14 may be subjected to gold plating, nickel / gold plating, OSP (Organic Solderability Preservatives) treatment, or the like.

[0028] The shape of the metal protrusions 14 is not particularly limited. Examples of the shape of the metal protrusions 14 include cylinders, rectangular parallelepipeds, triangular prisms, and other prisms. The metal protrusions 14 may also have a shape in which at least two cylinders, rectangular parallelepipeds, triangular prisms, and other shapes are stacked in the height direction. The tips of the metal protrusions 14 may be acute-angled. Examples of metal protrusions 14 with acute-angled tips include, but are not limited to, pyramids such as cones, triangular pyramids, and square pyramids, and shapes in which a pyramid is placed on a pillar. When the tips of the metal protrusions 14 are acute-angled, entrapment of the resin film tends to be further suppressed. Figure 2 is a cross-sectional view showing a modified example of the substrate 10 according to the first embodiment. In the substrate 10 shown in Figure 2, the metal protrusions 14 are pyramidal. Among the components constituting the resin film, inorganic fillers are a component that is likely to be entrapped between the protruding electrodes and the electrode pads. When the tips of the metal protrusions 14 are acute-angled, biting into the resin film tends to be more easily suppressed, even when a resin film with a high inorganic filler content is used. Therefore, using metal protrusions 14 with acute-angled tips tends to increase the inorganic filler content in the resin film 30. From this perspective, the inorganic filler content in the resin film 30 may be 50% by mass to 90% by mass based on the total amount of the resin film 30. Furthermore, the metal protrusions 14 are more likely to penetrate into the solder layer 24, improving the interlocking between the metal protrusions 14 and the solder layer 24 of the bump electrodes 26, increasing the strength against external forces during the reflow process and making it less likely that the semiconductor element 20 will be misaligned in subsequent steps.

[0029] The electrode pad 16 may have two or more metal protrusions 14 on the surface of the electrode pad body 12. When the electrode pad 16 has two or more metal protrusions 14 on the surface, the shapes of the metal protrusions 14 may be the same or different.

[0030] The thickness of the solder layer 24 of the bump electrode 26 is preferably greater than the height of the metal protrusion 14 of the electrode pad 16. This allows the metal protrusion 14 to penetrate the solder layer 24 more easily. Penetrating the metal protrusion 14 as deeply as possible into the solder layer 24 tends to increase the strength of the temporary fixing force and better suppress misalignment of the connection. The average height of the metal protrusion 14 is not particularly limited, but from the perspective of increasing the penetration of the metal protrusion 14 into the solder layer 24 and from the perspective of industrial productivity, it is preferably 0.1 μm to 50 μm, more preferably 0.5 μm to 30 μm, and even more preferably 1 μm to 10 μm. To improve the wettability of the solder when forming a connection between the metal protrusion 14 and the bump electrode 26 by solder melting, a gold-containing layer containing gold as the main component can also be formed on the outermost surface of the metal protrusion 14. The method for forming the gold-containing layer is not particularly limited, and methods such as plating and sputtering can be used.

[0031] The composition of the resin film 30 is not particularly limited, and may be a resin composition containing a thermoplastic resin, a thermosetting resin, an inorganic filler, etc. The resin composition constituting the resin film 30 may contain a flux component to improve the connectivity between the protruding electrodes and the electrode pads, if necessary.

[0032] When the resin film 30 contains a thermoplastic resin, it is preferable that the thermoplastic resin contains at least one selected from the group consisting of polyimide, polyamide, polycarbonate, polyacetal, polyphenylene ether, polybutylene terephthalate, polytetrafluoroethylene, polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, polyamideimide, polyetherimide, polyetheretherketone, acrylic resin, phenoxy resin, polyester, polyurethane, polybenzoxazole, and polybutadiene.

[0033] When the resin film 30 contains a thermosetting resin, the thermosetting resin preferably contains at least one selected from the group consisting of an epoxy resin, a polyamic acid, and a polyhydroxyamide. Here, the curing reaction of the polyamic acid produces polyimide. The curing reaction of the polyhydroxyamide produces polybenzoxazole.

[0034] When the resin film 30 contains an inorganic filler, examples of the inorganic filler include insulating inorganic fillers such as glass, silica, alumina, titanium oxide, mica, and boron nitride, and conductive inorganic fillers such as carbon black. Among these, insulating inorganic fillers selected from silica, alumina, titanium oxide, and boron nitride, or insulating inorganic fillers selected from silica, alumina, and boron nitride, are preferred. The inorganic filler may be whiskers, examples of which include aluminum borate, aluminum titanate, zinc oxide, calcium silicate, magnesium sulfate, and boron nitride. These inorganic fillers may be used alone or in combination of two or more. The resin film 30 may also contain a resin filler (organic filler). When the resin film 30 contains a resin filler, it may or may not contain an inorganic filler. Examples of resin fillers include polyurethane resin, polyimide resin, methyl methacrylate resin, and methyl methacrylate-butadiene-styrene copolymer resin (MBS). These resin fillers may be used alone or in combination of two or more. The inorganic fillers and resin fillers may be surface-treated to appropriately adjust their physical properties.

[0035] The resin film 30 preferably contains an epoxy resin from the viewpoint of achieving an excellent balance of various properties such as workability, formability, electrical properties, moisture resistance, heat resistance, mechanical properties, adhesiveness, etc. Below, a case where the resin film 30 contains an epoxy resin will be described.

[0036] The epoxy resin is not particularly limited as long as it has two or more epoxy groups in the molecule. Examples of the epoxy resin include various polyfunctional epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, naphthalene epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, phenol aralkyl epoxy resin, biphenyl epoxy resin, triphenylmethane epoxy resin, and dicyclopentadiene epoxy resin. These may be used alone or in combination of two or more.

[0037] The weight-average molecular weight of the epoxy resin is not particularly limited, but is preferably less than 10,000. In the present disclosure, the weight-average molecular weight is determined by measuring by gel permeation chromatography (GPC) and converting using a calibration curve of standard polystyrene. The GPC conditions are as follows. - GPC conditions - Pump: Hitachi L-6000 type (manufactured by Hitachi, Ltd.) Column: a total of three columns: Gelpack GL-R420, Gelpack GL-R430, and Gelpack GL-R440 (all of which are product names manufactured by Showa Denko Materials K.K.) Eluent: tetrahydrofuran Measurement temperature: 25°C Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI (manufactured by Hitachi, Ltd.)

[0038] The content of the epoxy resin is, for example, 5% by mass to 75% by mass, preferably 10% by mass to 50% by mass, and more preferably 15% by mass to 35% by mass, based on the total amount of the resin film 30.

[0039] When the resin film 30 contains an epoxy resin, the resin film 30 may contain a curing agent. Examples of curing agents include phenolic resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, imidazole-based curing agents, and phosphine-based curing agents. From the viewpoint of exhibiting flux activity that suppresses the formation of an oxide film on the bump electrodes 26 or electrode pads 16 and improving connection reliability and insulation reliability, it is preferable that the curing agent contain at least one selected from phenolic resin-based curing agents, acid anhydride-based curing agents, amine-based curing agents, and imidazole-based curing agents. Each curing agent will be described below.

[0040] The phenolic resin curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule, and examples thereof include phenol novolac resin, cresol novolac resin, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane type polyfunctional phenolic resin, and various polyfunctional phenolic resins. These can be used alone or in combination of two or more.

[0041] The equivalent ratio of the phenolic resin-based curing agent to the epoxy resin (phenolic hydroxyl group / epoxy group, molar ratio) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0, from the viewpoint of good curability, adhesion, and storage stability. When the equivalent ratio is 0.3 or higher, curability and adhesive strength tend to improve, while when it is 1.5 or lower, no excessive unreacted phenolic hydroxyl groups remain, the water absorption rate is kept low, and the insulating reliability of semiconductor devices tends to improve. When the equivalent ratio is 0.3 to 1.5, it is easy to adjust the gel time to an appropriate range.

[0042] Examples of acid anhydride curing agents include methylcyclohexanetetracarboxylic dianhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, and ethylene glycol bisanhydrotrimellitate. These may be used alone or in combination of two or more.

[0043] The equivalent ratio of the acid anhydride curing agent to the epoxy resin (acid anhydride group / epoxy group, molar ratio) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0, from the viewpoint of good curability, adhesion, and storage stability. When the equivalent ratio is 0.3 or more, curability and adhesive strength tend to improve, while when it is 1.5 or less, there is no excess unreacted acid anhydride remaining, the water absorption rate is kept low, and the insulating reliability of the semiconductor device tends to improve. When the equivalent ratio is 0.3 to 1.5, it is easy to adjust the gel time to an appropriate range.

[0044] As the amine-based curing agent, for example, dicyandiamide can be used.

[0045] The equivalent ratio of the amine curing agent to the epoxy resin (amino group / epoxy group, molar ratio) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, and even more preferably 0.5 to 1.0, from the viewpoint of good curability, adhesion, and storage stability. When the equivalent ratio is 0.3 or more, curability and adhesive strength tend to improve, while when it is 1.5 or less, there is no excess unreacted amine remaining, and the insulation reliability of the semiconductor device tends to improve. When the equivalent ratio is 0.3 to 1.5, it is easy to adjust the gel time to an appropriate range.

[0046] 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, 2,4-diamino-6 -[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 resins and imidazoles. From the viewpoint of excellent curing property, storage stability and connection reliability, 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-[2'-ethyl- The imidazole curing agent may be selected from 2,4-diamino-6-[2'-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, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. These may be used alone or in combination of two or more. Microcapsules containing these may also be used as latent curing agents.

[0047] The content of the imidazole curing agent is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 3.2 to 5.5 parts by mass, relative to 100 parts by mass of the epoxy resin. When the content of the imidazole curing agent is 0.1 parts by mass or more, the curing property of the resin film 30 tends to be improved, and when it is 20 parts by mass or less, connection failure tends to be less likely to occur. When the content of the imidazole curing agent is 0.1 to 20 parts by mass, it is easy to adjust the gel time to an appropriate range.

[0048] Examples of phosphine-based curing agents include triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(4-methylphenyl)borate, and tetraphenylphosphonium(4-fluorophenyl)borate.

[0049] The content of the phosphine-based curing agent is preferably 0.1 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the epoxy resin. When the content of the phosphine-based curing agent is 0.1 part by mass or more, the curing property of the resin film 30 tends to be improved, and when it is 10 parts by mass or less, connection defects tend to be less likely to occur.

[0050] The phenolic resin curing agent, the acid anhydride curing agent, and the amine curing agent can each be used alone or in combination of two or more. The imidazole curing agent and the phosphine curing agent can each be used alone, or can be used together with the phenolic resin curing agent, the acid anhydride curing agent, or the amine curing agent.

[0051] The resin film 30 may contain a fluxing agent. The fluxing agent is preferably a compound having two carboxy groups (dicarboxylic acid). Compared to a compound having one carboxy group (monocarboxylic acid), a compound having two carboxy groups is less likely to volatilize even at high temperatures during connection, and the occurrence of voids can be further suppressed. Furthermore, the use of a compound having two carboxy groups can further suppress the increase in viscosity of the resin film 30 during storage and connection work, compared to the use of a compound having three or more carboxy groups. As a result, the connection reliability of the semiconductor device can be further improved.

[0052] As the fluxing agent, for example, a compound in which an electron-donating group is substituted at the 2-position of a dicarboxylic acid selected from succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid can be used.

[0053] The melting point of the fluxing agent is preferably 150°C or lower, more preferably 140°C or lower, and even more preferably 130°C or lower. Such a fluxing agent exhibits sufficient fluxing activity before the curing reaction between the epoxy resin and the curing agent occurs. Therefore, a resin film 30 containing such a fluxing agent can realize a semiconductor device with even better connection reliability. Furthermore, the fluxing agent is preferably solid at room temperature, and the melting point of the fluxing agent is preferably 25°C or higher, more preferably 50°C or higher. The melting point of the fluxing agent can be measured, for example, using an apparatus in which a capillary tube filled with a sample is attached to a double-tube thermometer and heated in a warm bath.

[0054] The content of the fluxing agent is preferably 0.5% by mass to 10% by mass, and more preferably 0.5% by mass to 5% by mass, based on the total amount of the resin film 30 .

[0055] The resin film 30 may further contain a polymer component. The polymer component is composed of a polymer different from the epoxy resin. Examples of such polymer components include phenoxy resin, polyimide, polyamide, polycarbodiimide, cyanate ester, acrylic resin, polyester, polyethylene, polyethersulfone, polyetherimide, polyvinyl acetal, polyurethane, and acrylic rubber. From the viewpoint of excellent heat resistance and film formability, the polymer component is preferably phenoxy resin, polyimide, acrylic rubber, cyanate ester, or polycarbodiimide, and more preferably phenoxy resin, polyimide, or acrylic rubber. These polymer components can be used alone or as a mixture or copolymer of two or more types.

[0056] The weight-average molecular weight of the polymer component is not particularly limited, but is preferably 10,000 or more. In this case, the resin film 30 containing the polymer component is even more excellent in terms of heat resistance and film formability. From the viewpoint of imparting good film formability to the resin film 30 alone and making it easier to maintain the shape of the resin film 30, thereby efficiently manufacturing semiconductor devices, the weight-average molecular weight of the polymer component is preferably 30,000 or more, more preferably 40,000 or more, and even more preferably 50,000 or more.

[0057] When the resin film 30 contains a polymer component having a weight-average molecular weight of 10,000 or more, the ratio Ca / Cd (mass ratio) of the content Cd of the polymer component having a weight-average molecular weight of 10,000 or more to the content Ca of the epoxy resin is preferably 0.01 to 5, more preferably 0.05 to 3, and even more preferably 0.1 to 2. By setting the ratio Ca / Cd to 0.01 or more, better curing properties and adhesive strength can be obtained. Furthermore, by setting the ratio Ca / Cd to 5 or less, better film formability can be obtained in the resin film 30.

[0058] Specific examples of the inorganic filler when the resin film 30 contains the inorganic filler are as described above. From the viewpoint of adjusting the minimum melt viscosity of the resin film 30 within an appropriate range, the content of the inorganic filler is preferably 10% by mass to 80% by mass, and more preferably 15% by mass to 60% by mass, based on the total amount of the resin film 30.

[0059] The resin film 30 may further contain other components such as an ion trapper, an antioxidant, a silane coupling agent, a titanium coupling agent, and a leveling agent. These may be used alone or in combination of two or more. The amounts of these additives may be adjusted appropriately so that the effects of each additive are exerted.

[0060] The average thickness of the resin film 30 is not particularly limited, and can be set appropriately in consideration of the volume of the gap space between the substrate 10 and the semiconductor element 20 when the substrate 10 and the semiconductor element 20 are connected to form a semiconductor device, the volume of a fillet formed by the components of the resin film 30 leaking around the semiconductor element 20, and the like. For example, the average thickness of the resin film 30 may be set so that the sum of the average height of the pillars 22 and the average height of the metal protrusions 14 is smaller than the average thickness of the resin film 30. The average thickness of the resin film 30 is, for example, preferably 1 μm to 100 μm, more preferably 5 μm to 70 μm, and even more preferably 10 μm to 50 μm.

[0061] From the viewpoint of fluidity, the viscosity of the resin film 30 at 130°C is preferably 500 mPa·s to 4000 mPa·s, more preferably 700 mPa·s to 3000 mPa·s, and even more preferably 1000 mPa·s to 2000 mPa·s. The viscosity of the resin film 30 at 130°C is measured using a rheometer AR2000 (manufactured by TA Instruments, aluminum cone 40 mm, shear rate 32.5 / sec).

[0062] The resin film 30 can be produced by a method in which a resin varnish containing components that constitute the resin film 30, such as an epoxy resin, a curing agent, an inorganic filler, a fluxing agent, and, if necessary, an organic solvent and other components, is applied to a base film to form a coating film, and the coating film is then dried.

[0063] The resin varnish is prepared by mixing the components that make up the resin film 30, such as epoxy resin, curing agent, inorganic filler, and fluxing agent, with an organic solvent and dissolving or dispersing the mixture by stirring or kneading. The resin varnish is applied to a release-treated substrate film using, for example, a knife coater, roll coater, applicator, die coater, or comma coater. The organic solvent is then reduced from the resin varnish coating by heating, i.e., the coating is dried, forming the resin film 30 on the substrate film. The resin film 30 may also be formed on a semiconductor wafer or the like by forming a resin varnish film on the semiconductor wafer by a method such as spin coating, and then drying the coating.

[0064] The organic solvent used in preparing the resin varnish is preferably one that has the property of being able to uniformly dissolve or disperse each component, and examples thereof 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. These organic solvents can be used alone or in combination of two or more. Stirring and kneading during the preparation of the resin varnish can be performed using, for example, a stirrer, a kneading machine, a three-roll mill, a ball mill, a bead mill, or a homodisper.

[0065] The substrate film is not particularly limited as long as it has heat resistance sufficient to withstand the heating conditions when volatilizing the organic solvent, and examples thereof include polyolefin films such as polypropylene film and polymethylpentene film, polyester films such as polyethylene terephthalate film and polyethylene naphthalate film, polyimide film, polyetherimide film, etc. The substrate film is not limited to a single layer made of these films, and may also be a multilayer film made of two or more materials.

[0066] The heating performed to volatilize the organic solvent from the applied resin varnish may be, specifically, heating at 50° C. to 200° C. for 0.1 to 90 minutes. The organic solvent may be removed until the remaining amount is 1.5% by mass or less, within a range that does not substantially affect the suppression of void generation and the adjustment of viscosity.

[0067] The method for disposing the resin film 30 on the surface of the semiconductor element 20 facing the substrate 10 is not particularly limited. For example, the resin film 30 may be disposed on the surface of the semiconductor element 20 corresponding to the surface on which the resin film 30 is to be disposed, in a wafer-sized state before dicing, so as to cover the protruding electrodes 26, and then dicing may be performed to obtain the semiconductor element 20 with the resin film 30. While FIG. 1 shows the resin film 30 disposed on the surface of the semiconductor element 20 facing the substrate 10, the resin film 30 may also be disposed on the surface of the substrate 10 facing the semiconductor element 20. The location of the resin film 30 may be appropriately selected taking into consideration the arrangement of the protruding electrodes 26 on the semiconductor element 20 or the electrode pads 16 on the substrate 10, and the layout of the solder resist that may be applied to the substrate 10. From the viewpoints of embedding the unevenness of the protruding electrodes 26, electrode pads 16, etc., and ensuring the uniformity of the film thickness of the layer derived from the resin film 30, it is preferable that the resin film 30 be disposed on the surface of the semiconductor element 20 facing the substrate 10.

[0068] To arrange the resin film 30 on the semiconductor element 20 or the substrate 10, it is possible to use a heat roll lamination, a diaphragm lamination, a hot plate lamination, or the like, and a method of combining these methods alone or in combination may be selected. To improve and stabilize the lamination properties, the lamination process itself may be performed in a reduced pressure environment.

[0069] Next, in the contacting step, the bump electrodes 26 are aligned with the metal convex portions 14 provided on the electrode pads 16 facing the bump electrodes 26. Furthermore, in the contacting step, as shown in FIG. 3, the bump electrodes 26 and the electrode pads 16 having the metal convex portions 14 are pressed together while facing each other, causing the metal convex portions 14 of the electrode pads 16 to penetrate into the solder layers 24 of the bump electrodes 26, thereby provisionally mounting the semiconductor element 20 on the substrate 10. The provisional mounting of the semiconductor element 20 on the substrate 10 can be performed using a flip-chip bonder or the like. By provisionally mounting the semiconductor element 20 on the substrate 10 with the resin film 30 interposed therebetween, the occurrence of misalignment of the semiconductor element 20 tends to be suppressed.

[0070] The magnitude of the pressure applied when applying pressure is not particularly limited. As with a typical flip-chip mounting process, the magnitude can be set taking into consideration the number of protruding electrodes 26, variations in the height of the protruding electrodes 26, and the amount of deformation of the protruding electrodes 26 or the wiring on the substrate 10 due to pressure. Specifically, for example, it is preferable to set the load applied to each protruding electrode to approximately 1 gf (0.0098 N) to 20 gf (0.196 N). It is also preferable to set the load applied to each semiconductor element 20 to approximately 5 N to 200 N. If the load applied to each protruding electrode is 0.0098 N or more or the load applied to the semiconductor element 20 is 5 N or more, the force for temporarily fixing the semiconductor element 20 to the substrate 10 is sufficient, and misalignment of the semiconductor element 20 in subsequent processes is less likely to occur. If the load per protruding electrode is 0.196 N or less, or the load applied to the semiconductor element 20 is 200 N or less, damage to the semiconductor element 20 due to excessive load tends to be suppressed.

[0071] When applying pressure to the solder layer 24 and the metal protrusions 14 while they are in contact with each other, at least one of the substrate 10 and the semiconductor element 20 may be heated. From the viewpoint of productivity, it is preferable to bring the solder layer 24 and the tips of the metal protrusions 14 into contact with each other with the resin film 30 interposed therebetween while heating at a temperature equal to or lower than the melting temperature of the solder constituting the solder layer 24. Contact at a temperature of 210°C or lower is more preferable, and contact at a temperature of 200°C or lower is even more preferable. When applying pressure to the solder layer 24 and the metal protrusions 14 while they are in contact with each other, voids may form between the resin film 30 and the semiconductor element 20 and / or between the resin film 30 and the substrate 10. If these voids remain, they will remain as voids in the semiconductor device. The voids can be eliminated by compressing the resin film 30 by applying pressure.

[0072] Then, in the connection process, the semiconductor element 20 is temporarily stacked on the substrate 10, and a heating device, typically a reflow furnace, is used to melt the solder layer 24, soldering the protruding electrodes 26 of the semiconductor element 20 to the electrode pads 16 having the metal protrusions 14 on the substrate 10, thereby connecting the substrate 10 and the semiconductor element 20. Through the above process, a semiconductor device is manufactured in which the metal protrusions 14 penetrate the solder layer 24, as shown in FIG. 4. Furthermore, if a resin film containing a thermosetting resin is used as the resin film 30, the resin film 30 hardens as the solder connection is made, forming a hardened resin layer 32 between the semiconductor element 20 and the substrate 10. The heating device is not limited to a reflow furnace, and a hot plate, oven, etc. can also be used.

[0073] The heating temperature in the connection step is preferably a temperature at which the solder melts, more preferably 220°C or higher, and even more preferably 230°C or higher. The connection step is preferably carried out in a nitrogen atmosphere to prevent oxidation of the bump electrodes 26 and the electrode pads 16 having the metal protrusions 14. The connection step may be carried out while applying pressure. By connecting the substrate 10 and the semiconductor element 20 while applying pressure, it is more likely that the resin film 30 will be more easily prevented from becoming trapped. The pressure conditions are not particularly limited.

[0074] Second Embodiment Next, a method for manufacturing a semiconductor device according to a second embodiment of the present disclosure will be described with reference to FIGS. 5 to 7. In the method for manufacturing a semiconductor device according to the second embodiment, four semiconductor elements are stacked in the thickness direction of a substrate. In the second embodiment, as shown in FIG. 5, a semiconductor element body 21 is provided with electrode pads 16 having metal protrusions 14 on the surface opposite to the surface on which protruding electrodes 26 having solder layers 24 at their tips are provided. In the semiconductor element 20 according to the second embodiment, the protruding electrodes 26 and the electrode pads 16 may be connected to each other via a TSV structure (not shown).

[0075] In the second embodiment, as shown in FIG. 6 , multiple semiconductor elements 20 are stacked on the semiconductor elements 20 stacked on the substrate 10 by repeatedly stacking the semiconductor elements 20 on the substrate 10, with the solder layer 24 of one semiconductor element 20 in contact with the tip of the metal protrusion 14 of another semiconductor element 20, with a resin film 30 interposed between the one semiconductor element 20 and the other semiconductor elements 20. Note that, among the semiconductor elements stacked on the substrate 10, the semiconductor element 20 (semiconductor element 20A) furthest from the substrate 10 does not need to be provided with an electrode pad. Next, the solder layer 24 is melted by heating to collectively connect the substrate 10 and the multiple semiconductor elements 20, thereby manufacturing a semiconductor device in which the metal protrusion 14 penetrates the solder layer 24, as shown in FIG. 7 . Furthermore, when a resin film containing a thermosetting resin is used as the resin film 30, the resin film 30 hardens as the solder connection is made, forming a cured resin layer 32 between the semiconductor elements 20 and the substrate 10 and between the semiconductor elements 20. The details of the semiconductor elements, substrate, and resin film used in the manufacturing method of the semiconductor device according to the second embodiment, as well as the conditions for the contacting step, connecting step, and other steps, are the same as those in the manufacturing method of the semiconductor device according to the first embodiment. Note that, although the substrate 10 and the multiple semiconductor elements 20 are connected together by heating in the second embodiment, a semiconductor device can also be manufactured by repeatedly stacking and connecting the substrate 10 and the semiconductor elements 20 individually.

[0076] <Substrate and semiconductor element> The substrate of the present disclosure includes an electrode pad having a metal protrusion with an acute tip on its surface. Details of the substrate of the present disclosure are as described in the method for manufacturing a semiconductor device according to the first embodiment. The semiconductor element of the present disclosure includes an electrode pad having a metal protrusion with an acute tip on its surface. Details of the semiconductor element of the present disclosure are as described in the methods for manufacturing a semiconductor device according to the first and second embodiments.

[0077] All publications, patent applications, and technical standards mentioned in this specification are incorporated by reference into this specification to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

[0078] REFERENCE SIGNS LIST 10 Substrate 11 Substrate body 12 Electrode pad body 14 Metal convex portion 16 Electrode pad 20 Semiconductor element 21 Semiconductor element body 22 Pillar 24 Solder layer 26 Protruding electrode 30 Resin film 32 Cured resin layer

Claims

1. a semiconductor element having a protruding electrode with a solder layer at its tip end, and a substrate having an electrode pad with a metal protrusion on a surface of the semiconductor element opposite to the surface having the protruding electrode, with a resin film interposed between the semiconductor element and the substrate, and the solder layer of the semiconductor element is brought into contact with the tip of the metal protrusion on the substrate, and the semiconductor element is stacked on the substrate; melting the solder layer by heating to connect the substrate and the semiconductor element; and The tip of the metal convex portion is acute-angled. A method for manufacturing a semiconductor device.

2. the semiconductor element stacked on the substrate is provided with an electrode pad having a metal protrusion on its surface on a surface opposite to the surface on which the protruding electrode is provided, a plurality of semiconductor elements each having a protruding electrode with a solder layer at the tip thereof on one side and an electrode pad with a metal protrusion on the surface thereof on the other side are stacked on the semiconductor element stacked on the substrate by contacting the solder layer of one semiconductor element with the tip of the metal protrusion of another semiconductor element with the resin film interposed between the one semiconductor element and the other semiconductor element, thereby stacking the plurality of semiconductor elements on the semiconductor element stacked on the substrate; 2. The method for manufacturing a semiconductor device according to claim 1, wherein the solder layer is melted by heating to connect the substrate and the plurality of semiconductor elements together.

3. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the solder layer and the tip of the metal convex portion are brought into contact with each other with the resin film interposed therebetween while heating under conditions below the melting temperature of the solder constituting the solder layer.

4. 3. A method for manufacturing a semiconductor device as described in claim 1 or claim 2, wherein the protruding electrode has a pillar and the solder layer provided at the tip of the pillar, and the sum of the average height of the pillar and the average height of the metal convex portion is smaller than the average thickness of the resin film.

5. 5. The method for manufacturing a semiconductor device according to claim 4, wherein the average height of the pillars is 20 μm or less. 。

6. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the resin film contains a thermosetting resin.

7. 7. The method for manufacturing a semiconductor device according to claim 6, wherein the thermosetting resin comprises at least one selected from the group consisting of epoxy resin, polyamic acid, and polyhydroxyamide.

8. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the resin film contains a thermoplastic resin.

9. 9. The method for manufacturing a semiconductor device according to claim 8, wherein the thermoplastic resin comprises at least one selected from the group consisting of polyimide, polyamide, polycarbonate, polyacetal, polyphenylene ether, polybutylene terephthalate, polytetrafluoroethylene, polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, polyamideimide, polyetherimide, polyetheretherketone, acrylic resin, phenoxy resin, polyester, polyurethane, polybenzoxazole, and polybutadiene.

10. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the resin film contains an inorganic filler.

11. 11. The method for manufacturing a semiconductor device according to claim 10, wherein the content of the inorganic filler is 10% by mass to 80% by mass based on the total amount of the resin film.

12. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the resin film has a viscosity of 500 mPa·s to 4000 mPa·s at 130° C.

13. A semiconductor element having a protruding electrode having a solder layer at the tip on one side and an electrode pad having a metal protrusion on the surface on the other side.

14. A semiconductor element as described in claim 13, wherein the tip of the metal convex portion is sharp.