Manufacturing method for semiconductor devices

Abstract

The present invention provides a method for manufacturing a semiconductor device that yields a bonded body with good electrical connectivity and suppressed inclusion of air bubbles in the resin. [Solution] A method for manufacturing a semiconductor device, wherein the circuit forming surface (α) of the first member and the circuit forming surface (β) of the second member each have a complex viscosity of 1 × 10 at 80°C. 4 Step (S1) is to prepare a first and second workpiece to be bonded, each having a thermosetting resin film (x) with a viscosity of less than Pa·s attached, and at least one of the thermosetting resin films (x) being in an uncured state; Step (S2) is to bond the circuit-forming surface (α) side of the first workpiece to the circuit-forming surface (β) side of the second workpiece to each other by bringing them into opposing contact and bonding them together to obtain a temporary bond; Step (S2) is to bond the temporary bonded workpiece to the thermosetting resin film (x) having a complex viscosity of 1 × 10 4 The process includes (S3) heating the thermosetting resin film (x) to a temperature of less than Pa·s, then further increasing the temperature to thermoset the film and obtain a bonded body.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing a semiconductor device. [Background technology]

[0002] In recent years, with the miniaturization and thinning of electronic devices, there has been an increasing demand for thinner and smaller semiconductor packages. Therefore, as a mounting method for semiconductor elements, a flip-chip mounting method has been proposed as an alternative to the conventional wire bonding method, which uses metal wires for connection. This method involves forming protruding electrodes, such as bumps, on the chip's electrodes and directly connecting the substrate electrodes to the chip electrodes via these protruding electrodes. Furthermore, in recent years, it has also been proposed that the tops of the protruding electrodes be joined together in the flip-chip mounting method.

[0003] Incidentally, in the flip-chip mounting method, it is common practice to seal the gap between the substrate and the chip with resin for purposes such as reinforcing the connection point and improving reliability. One known resin encapsulation method is the capillary underfill method. This method involves applying a liquid encapsulation resin composition to one or more sides of a semiconductor chip and using capillary action to allow the liquid encapsulation resin composition to flow into the gap between the substrate and the semiconductor chip (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2007-217708 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the liquid encapsulating resin composition used in the capillary underfill method is problematic in terms of handling because it is a liquid. Therefore, the inventors investigated the creation of a new process for resin encapsulation by using a film-like resin composition, which has excellent handling properties, instead of a liquid encapsulating resin composition, and by firmly bonding two components such as a substrate and a semiconductor chip. However, during this investigation, it was found that a problem arose in the resin encapsulation product where air bubbles were incorporated. The incorporation of air bubbles into the resin composition causes problems such as impairing the appearance of the product and should be suppressed as much as possible.

[0006] The present invention aims to provide a method for manufacturing a semiconductor device in which a bonded body can be obtained using a film-like resin composition, in which two components, such as a substrate and a chip, are firmly bonded together while being resin-sealed, while also having good electrical connectivity and suppressing the incorporation of air bubbles into the resin. [Means for solving the problem]

[0007] The present invention provides the following [1] to [6]. [1] A method for manufacturing a semiconductor device, comprising obtaining a joint in which a first member having a circuit forming surface (α) and a second member having a circuit forming surface (β) are electrically connected via a protruding electrode provided on at least one of the circuit forming surface (α) and the circuit forming surface (β), The circuit-forming surface (α) of the first member and the circuit-forming surface (β) of the second member each have a complex viscosity of 1.0 × 10 at 80°C. 4 Step (S1) of preparing a first and second workpiece to be joined, wherein a thermosetting resin film (x) with a Pa·s of less than s is attached, and at least one of the thermosetting resin films (x) is in an uncured state, Step (S2) is to bring the surface of the first workpiece to be joined on the circuit-forming surface (α) side and the surface of the second workpiece to be joined on the circuit-forming surface (β) side into opposing contact and bond them together to obtain a temporary joint, The temporary joint is formed when the complex viscosity of the thermosetting resin film (x) is 1 × 10 4After heating within a range of less than Pa·s, the temperature is further raised to thermally cure the thermosetting resin film (x) to obtain the bonded body (step S3). A method for manufacturing a semiconductor device, comprising: [2] The method for manufacturing a semiconductor device according to [1] above, wherein the thermosetting resin film (x) used in the step (S1) is a composite sheet provided with a support sheet. [3] The method for manufacturing a semiconductor device according to [1] or [2] above, wherein a flux agent is blended in the thermosetting resin film (x). [4] The method for manufacturing a semiconductor device according to any one of [1] to [3] above, wherein the thermosetting resin film (x) contains a polyvinyl acetal resin. [5] A thermosetting resin film used in the manufacturing method according to any one of [1] to [4] above. [6] A composite sheet including a thermosetting resin film and a support sheet, the thermosetting resin film being used in the manufacturing method according to any one of [1] to [4] above. [Effect of the Invention]

[0008] According to the present invention, by using a film-shaped resin composition, two members such as a substrate and a chip are firmly bonded while being resin-sealed, and the electrical connectivity is also good. Moreover, it is possible to provide a method for manufacturing a semiconductor device capable of obtaining a bonded body in which the incorporation of air bubbles into the resin is suppressed. [Brief Description of the Drawings]

[0009] [Figure 1] It is a schematic cross-sectional view showing an example of an embodiment of the composite sheet of the present embodiment. [Figure 2] It is a schematic cross-sectional view showing another example of an embodiment of the composite sheet of the present embodiment. [Figure 3] It is a schematic cross-sectional view showing still another example of an embodiment of the composite sheet of the present embodiment. [Figure 4] It is a schematic cross-sectional view showing an example of the step (S11) in the step (S1). [Figure 5]This is a schematic cross-sectional view showing an example of process (S12) in process (S1). [Figure 6] This is a schematic cross-sectional view showing an example of process (S13) in process (S1). [Figure 7] This is a schematic cross-sectional view showing an example of process (S2). [Figure 8] This is a schematic cross-sectional view showing an example of process (S3) (jointed body). [Figure 9] This is a schematic cross-sectional view showing another example (temporary joint) in process (S2). [Modes for carrying out the invention]

[0010] In this specification, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​on a standard polystyrene basis measured by gel permeation chromatography (GPC), specifically values ​​measured based on the method described in the Examples.

[0011] In this specification, the lower and upper limits described in steps for a preferred numerical range (e.g., range of content, etc.) can be combined independently. For example, from the description "preferably 10 to 90, more preferably 30 to 60", the "preferred lower limit (10)" and the "more preferred upper limit (60)" can be combined to arrive at "10 to 60".

[0012] In this specification, "energy beam" means an electromagnetic wave or charged particle beam that has an energy quantum. Examples of energy beams include ultraviolet rays, radiation, and electron beams. Ultraviolet rays can be irradiated using electrodeless lamps, high-pressure mercury lamps, metal halide lamps, xenon lamps, black lights, LED lamps, etc. Electron beams can be irradiated using those generated by electron accelerators, etc.

[0013] In this specification, "energy ray curable" means the property of hardening by irradiation with energy rays. Also in this specification, "thermosetting" means the property of hardening by heating, and "non-curable" means the property of not hardening by heating or irradiation with energy rays.

[0014] In this specification, for example, "(meth)acrylic acid" refers to both "acrylic acid" and "methacrylic acid," and the same applies to other similar terms.

[0015] In this specification, "protruding electrode" refers to a protruding electrode of a shape commonly used on the circuit formation surface of semiconductor wafers, semiconductor chips, etc., such as ball bumps and pillar electrodes.

[0016] In this specification, the "thickness" of an object means the total thickness of the object as a whole. For example, if the object consists of multiple layers, it means the total thickness of all the layers that make up the object. In this specification, unless otherwise specified, the "thickness" of an object refers to the average value of the thickness measured at five randomly selected locations on the object, and can be obtained using a constant-pressure thickness measuring instrument in accordance with JIS K 7130:1999.

[0017] In this specification, "solid content" or "active ingredient" refers to the components of the composition in question, excluding diluting solvents such as water and organic solvents.

[0018] The mechanism of action described herein is speculative and does not limit the mechanism by which the present invention achieves its effects.

[0019] In order to make the features of the present invention easier to understand, the drawings may show enlarged versions of key parts for convenience, and the dimensional ratios of each component may not be the same as in reality.

[0020] [Method for manufacturing the semiconductor device of this embodiment] The semiconductor device manufacturing method of this embodiment is a method for manufacturing a semiconductor device in which a first member having a circuit forming surface (α) and a second member having a circuit forming surface (β) are electrically connected via a protruding electrode provided on at least one of the circuit forming surface (α) and the circuit forming surface (β), and the method includes steps (S1) to (S3). In step (S1), the circuit-forming surface (α) of the first member and the circuit-forming surface (β) of the second member are each given a complex viscosity of 1 × 10 at 80°C. 4 Prepare a first and a second workpiece, each having a thermosetting resin film (x) with a curing rate of less than Pa·s attached, and at least one of the thermosetting resin films (x) being in an uncured state. In step (S2), the circuit-forming surface (α) of the first body to be joined and the circuit-forming surface (β) of the second body to be joined are brought into opposing contact and bonded to obtain a temporary joint. In step (S3), the temporary bond is formed when the complex viscosity of the uncured thermosetting resin film (x) is 1 × 10⁻⁶. 4 After heating to a temperature below Pa·s, the temperature is further increased to heat-cur the thermosetting resin film (x) and obtain the bonded body.

[0021] The inventors diligently conducted research to solve the above problems. As a result, in step (S1), the complex viscosity at 80°C is 1 × 10⁻¹⁰ 4 We have found that by preparing a first and second bonded body to which a thermosetting resin film (x) having a Pa·s of less than 50°C is attached, and in which at least one of the thermosetting resin films (x) is in an uncured state, the following effects (1) and (2) can be obtained, and as a secondary effect, the following (3) can also be obtained. (1) In step (S3), pressurized heating is performed, causing the uncured thermosetting resin film (x) to be heat-cured, thereby firmly bonding the bonding surface (interface). As a result, the first and second objects to be bonded can be firmly joined. (2) The protruding electrodes are protected by the thermosetting resin film (x), thereby suppressing deformation of the protruding electrodes in processes (S2) and (S3), preventing short circuits between adjacent protruding electrodes, and ensuring good electrical connectivity. (3) In step (S2), the uncured thermosetting resin film (x) has tack, so the first to be bonded and the second to be bonded can be bonded together to obtain a temporary bond. In other words, it is possible to temporarily fix the first to be bonded and the second to be bonded together. Then, in process (S3), the complex viscosity of the thermosetting resin film (x) is 1 × 10 4 We have also found that by heating the thermosetting resin film (x) to a temperature below Pa·s and then further increasing the temperature to thermoset it, the following effect (4) can be obtained. (4) When bonding the circuit-forming surface (α) side of the first body to be bonded and the circuit-forming surface (β) side of the second body to be bonded together, air bubbles that may enter the bonding surface (interface) can be expelled from the system, resulting in a better bonding state.

[0022] In this embodiment, the first member having a circuit formation surface (α) and the second member having a circuit formation surface (β) are not particularly limited, but the first member can be, for example, a semiconductor chip with a protruding electrode on the circuit formation surface (α). Examples of the second component include a substrate with wiring provided on its circuit-forming surface (β). The second component may also be a substrate with protruding electrodes provided on its circuit-forming surface (α), or, similar to the first component, a semiconductor chip with protruding electrodes provided on its circuit-forming surface (α).

[0023] In this embodiment, the thermosetting resin film (x) and the composite sheet comprising the thermosetting resin film (x) and a support sheet used in the above-described semiconductor device manufacturing method will be described in detail, followed by a detailed explanation of each step.

[0024] <Thermosetting resin film (x)> The thermosetting resin film (x) is used when preparing the first joined body and the second joined body in step (S1). The thermosetting resin film (x) has a complex viscosity at 80°C of less than 1×10 4 Pa·s. Therefore, it has tack in the uncured state and it becomes possible to produce a temporary joined body in step (S2). Moreover, the thermosetting resin film (x) having a complex viscosity at 80°C of less than 1×10 4 Pa·s is soft and has high followability to the uneven surface. Therefore, the thermosetting resin film (x) exhibits high adhesion to the unevenness of the circuit formation surface (α) of the first member and the circuit formation surface (β) of the second member.

[0025] The thermosetting resin film (x) may be only one layer or may be a plurality of layers of two or more. When the thermosetting resin film (x) is a plurality of layers, these plurality of layers may be the same as or different from each other, and the combination of these plurality of layers is not particularly limited. Note that, from the viewpoint of easily discharging bubbles that can enter the bonding surface (interface) to the outside of the system when the circuit formation surface (α) side of the first joined body and the circuit formation surface (β) side of the second joined body are brought into opposed contact and bonded, the complex viscosity of the thermosetting resin film (x) at 80°C is preferably 5×10 3 Pa·s or less, more preferably 2×10 3 Pa·s or less, and still more preferably 1.2×10 3 Pa·s or less. Also, from the viewpoint of the moldability etc. of the thermosetting resin film (x), the complex viscosity of the thermosetting resin film (x) at 80°C is preferably 1.0×10 2 Pa·s or more, more preferably 1.3×10 2 Pa·s or more, and still more preferably 1.5×10 2 Pa·s or more. The complex viscosity of the thermosetting resin film (x) at 80°C can be measured by the method described in the examples below. Furthermore, the complex viscosity of the thermosetting resin film (x) at 80°C can be adjusted by adjusting one or both of the types and / or amounts of components contained in the composition for forming the thermosetting resin film (x).

[0026] The thickness of the thermosetting resin film (x) is adjusted as appropriate, taking into consideration the thickness of the cured resin film formed by curing the thermosetting resin film (x), the unevenness of the circuit-forming surface (α) of the first member (if there are protruding electrodes, their height and number (installation density of protruding electrodes)), and the unevenness of the circuit-forming surface (β) of the second member (if there are protruding electrodes, their height and number (installation density of protruding electrodes)), etc. The thickness of the thermosetting resin film (x) is preferably 5 to 70 μm, more preferably 10 to 60 μm, and even more preferably 15 to 45 μm. If the thickness of the thermosetting resin film (x) is greater than or equal to the lower limit, it is easier to produce a film with high in-plane uniformity, and insulation is ensured because it can follow the circuit formation surface without any gaps. On the other hand, if the thickness of the thermosetting resin film (x) is less than or equal to the upper limit, it is possible to prevent the thermosetting resin film (x) from becoming excessively thick, making it possible to create a thinner semiconductor device. The thickness of the thermosetting resin film (x) attached to the circuit-forming surface (α) of the first member and the thickness of the thermosetting resin film (x) attached to the circuit-forming surface (β) of the second member may be the same or different.

[0027] Here, the thickness T [μm] of the thermosetting resin film (x) may be calculated using the following formula. T = H × (100 - Vb) / 100 In the above formula, H is the height of the protruding electrode [μm], and Vb is the occupancy rate [%] of the space between the circuit forming surface (α) of the first member or the circuit forming surface (β) of the second member and the surface formed by connecting the vertices of the protruding electrode. The thickness T [μm] of the thermosetting resin film (x) calculated using the above formula may vary by approximately 10%.

[0028] The thermosetting resin film (x) contains a polymer component (A) and a thermosetting component (B). The thermosetting resin film (x) is formed, for example, from a thermosetting resin composition (x1) containing a polymer component (A) and a thermosetting component (B). Polymeric component (A) is a component that can be considered to have been formed by a polymerization reaction of polymerizable compounds. Thermosetting component (B) is a component that can undergo a curing (polymerization) reaction triggered by heat. This curing (polymerization) reaction includes polycondensation reactions. The composition of the thermosetting resin film (x) attached to the circuit-forming surface (α) of the first member and the composition of the thermosetting resin film (x) attached to the circuit-forming surface (β) of the second member may be the same or different, but it is preferable that they be the same from the viewpoint of more firmly joining the first member and the second member.

[0029] (Polymer component (A)) The thermosetting resin film (x) and the thermosetting resin composition (x1) contain a polymer component (A). Polymer component (A) is a polymer compound used to impart film-forming properties, flexibility, and other characteristics to the thermosetting resin film (x). Polymer component (A) may be used alone or in combination of two or more types. When two or more polymer components (A) are used in combination, the combination and ratio can be arbitrarily selected.

[0030] Examples of polymer components (A) include acrylic resins, polyarylate resins, acetal resins, polyesters, urethane resins (resins having urethane bonds), acrylic urethane resins, silicone resins (resins having siloxane bonds), rubber resins (resins having a rubber structure), phenoxy resins, and thermosetting polyimides. Among these, acrylic resins, polyarylate resins, and acetal resins are preferred, with acetal resins being more preferred, from the viewpoint of easily adjusting the complex viscosity at 80°C.

[0031] Examples of acrylic resins include well-known acrylic polymers. The weight-average molecular weight (Mw) of the acrylic resin is preferably 10,000 to 2,000,000, more preferably 300,000 to 1,500,000, and even more preferably 500,000 to 1,000,000. Having a weight-average molecular weight of the acrylic resin above the lower limit mentioned above makes it easier to improve the shape stability (stable over time during storage) of the thermosetting resin film (x). Also, having a weight-average molecular weight of the acrylic resin below the upper limit mentioned above makes it easier for the thermosetting resin film (x) to conform to the uneven surface of the adherend, for example, making it easier to suppress the generation of voids between the adherend and the thermosetting resin film (x). Therefore, the coverage of the circuit-forming surface (α) and circuit-forming surface (β) is improved, and the ability to fill grooves that these surfaces may have is also improved.

[0032] The glass transition temperature (Tg) of the acrylic resin is preferably -60 to 70°C, more preferably -40 to 50°C, and even more preferably -30 to 30°C, from the viewpoint of the adhesiveness and handling properties of the thermosetting resin film (x).

[0033] Examples of acrylic resins include polymers of one or more (meth)acrylic acid esters; copolymers of two or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide, etc.

[0034] Examples of (meth)acrylic acid esters that constitute acrylic resins include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, and (meth) Alkyl methacrylates such as isononyl acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl ((meth)acrylate) (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl ((meth)acrylate) (myristyl (meth)acrylate), pentadecyl (meth)acrylate, hexadecyl ((meth)acrylate) (palmityl (meth)acrylate), heptadecyl (meth)acrylate, and octadecyl ((meth)acrylate) (stearyl (meth)acrylate), in which the alkyl group constituting the alkyl ester has a chain structure with 1 to 18 carbon atoms; Cycloalkyl esters of (meth)acrylates, such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (meth)acrylate aralkyl esters such as benzyl (meth)acrylate; (meth)acrylate dicyclopentenyl ester and other cycloalkenyl (meth)acrylates; (meth)acrylate cycloalkenyloxyalkyl esters such as (meth)acrylate dicyclopentenyloxyethyl ester; (meth)acrylimide; Glycidyl group-containing (meth)acrylic acid esters such as glycidyl (meth)acrylate; Hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, and other hydroxyl group-containing (meth)acrylate esters; Examples include (meth)acrylic acid esters containing substituted amino groups, such as N-methylaminoethyl (meth)acrylate. In this specification, "substituted amino group" means a group in which one or two hydrogen atoms of an amino group are replaced by a group other than a hydrogen atom. Among these, from the viewpoint of film-forming properties of the thermosetting resin film (x) and adhesion properties of the thermosetting resin film (x) to the circuit-forming surface (α) and circuit-forming surface (β), it is preferable that the alkyl group constituting the alkyl ester is a copolymer of (meth)acrylate alkyl ester having a chain structure with 1 to 18 carbon atoms, glycidyl group-containing (meth)acrylate ester, and hydroxyl group-containing (meth)acrylate ester; it is more preferable that the alkyl group constituting the alkyl ester is a copolymer of (meth)acrylate alkyl ester having a chain structure with 1 to 4 carbon atoms, glycidyl group-containing (meth)acrylate ester, and hydroxyl group-containing (meth)acrylate ester; and it is even more preferable that it is a copolymer of butyl acrylate, methyl acrylate, glycidyl acrylate, and 2-hydroxyethyl acrylate.

[0035] The acrylic resin may be obtained by copolymerizing one or more monomers selected from, for example, (meth)acrylic acid ester, (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide, in addition to (meth)acrylic acid ester.

[0036] The monomers that make up the acrylic resin may be used individually or in combination of two or more. When the monomers that make up the acrylic resin are two or more, their combination and ratio can be arbitrarily selected.

[0037] Examples of polyarylate resins in polymer component (A) include known resins, such as those whose basic structure is the polycondensation of a divalent phenol with a dibasic acid such as phthalic acid or a carboxylic acid. Among these, polycondensates of bisphenol A and phthalic acid, poly-4,4'-isopropylidenediphenylene terephthalate / isophthalate copolymers, and their derivatives are preferred.

[0038] Examples of the acetal resin in polymer component (A) include those that are well known. Among these, preferred acetal resins include, from the viewpoint of easily adjusting the complex viscosity at 80°C, polyvinyl acetal resins such as polyvinyl formal and polyvinyl butyral, with polyvinyl butyral being the most preferred among them. Examples of polyvinyl butyral include those having constituent units represented by the following formulas (i)-1, (i)-2, and (i)-3.

[0039] [ka]

[0040] (In the formula, l, m, and n are each an independent integer greater than or equal to 1.)

[0041] The weight-average molecular weight (Mw) of the polyvinyl acetal resin (preferably polyvinyl butyral) is preferably 5,000 to 200,000, and more preferably 8,000 to 100,000. Having a weight-average molecular weight of the polyvinyl acetal resin (preferably polyvinyl butyral) above the lower limit makes it easier to improve the shape stability (stable over time during storage) of the thermosetting resin film (x). Furthermore, having a weight-average molecular weight of the polyvinyl acetal resin (preferably polyvinyl butyral) below the upper limit makes it easier for the thermosetting resin film (x) to conform to the uneven surface of the adherend, for example, making it easier to suppress the generation of voids between the adherend and the thermosetting resin film (x). Therefore, the coverage of the circuit-forming surface (α) and circuit-forming surface (β) is improved, and the embedding ability into the irregularities that the first and second members may have is also improved.

[0042] The glass transition temperature (Tg) of the polyvinyl acetal resin (preferably polyvinyl butyral) is preferably 40 to 80°C, and more preferably 50 to 70°C, from the viewpoint of the film-forming properties of the thermosetting resin film (x) and the protrusion of the tops of the protruding electrodes on at least one of the circuit-forming surfaces (α) and (β). Herein, in this specification, "the ability of the top of the protruding electrode to penetrate the thermosetting resin film (x) when the thermosetting resin film (x) is attached to the circuit forming surface" refers to the ability of the top of the protruding electrode to penetrate the thermosetting resin film (x), and is also referred to as "the ability of the top of the protruding electrode to penetrate".

[0043] The ratio of three or more monomers that make up the polyvinyl acetal resin (preferably polyvinyl butyral) can be arbitrarily selected.

[0044] In the thermosetting resin film (x) and the thermosetting resin composition (x1), the content of polymer component (A) is preferably 2 to 30% by mass, more preferably 3 to 25% by mass, and even more preferably 3 to 15% by mass, based on the total amount of active ingredients.

[0045] Polymer component (A) may also correspond to thermosetting component (B). In this embodiment, if thermosetting resin composition (x) and thermosetting resin composition (x1) contain components that correspond to both polymer component (A) and thermosetting component (B), thermosetting resin composition (x) and thermosetting resin composition (x1) are considered to contain both polymer component (A) and thermosetting component (B).

[0046] (Thermosetting component (B)) The thermosetting resin film (x) and the thermosetting resin composition (x1) contain a thermosetting component (B). The thermosetting component (B) is a component that cures the thermosetting resin film (x) to form a hard, cured resin film. The thermosetting component (B) may be used alone or in combination of two or more types. If there are two or more types of thermosetting component (B), their combination and ratio can be arbitrarily selected.

[0047] Examples of thermosetting component (B) include epoxy thermosetting resins, thermosetting polyimides, polyurethanes, unsaturated polyesters, and silicone resins. Among these, epoxy thermosetting resins are preferred. When thermosetting component (B) is an epoxy thermosetting resin, the protective properties of the cured resin film and the protrusion of the top of the protruding electrode are improved, and warping of the cured resin film can be suppressed.

[0048] Epoxy thermosetting resins consist of an epoxy resin (B1) and a thermosetting agent (B2). Epoxy thermosetting resins may be used individually or in combination of two or more types. When two or more epoxy thermosetting resins are used, their combination and ratio can be arbitrarily selected.

[0049] -Epoxy resin (B1)- While there are no particular limitations on the epoxy resin (B1), it is preferable to use a combination of an epoxy resin that is solid at room temperature (hereinafter also referred to as a solid epoxy resin) and an epoxy resin that is liquid at room temperature (hereinafter also referred to as a liquid epoxy resin) from the viewpoint of making it easier to appropriately adjust the complex viscosity at 80°C. In this specification, "room temperature" refers to 25°C.

[0050] The liquid epoxy resin is not particularly limited as long as it is liquid at room temperature. Examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin, and phenylene skeleton type epoxy resin. Among these, bisphenol A type epoxy resin is preferred. Liquid epoxy resin may be used alone or in combination of two or more types. When two or more types of liquid epoxy resin are used, their combination and ratio can be arbitrarily selected.

[0051] The epoxy equivalent of the liquid epoxy resin is preferably 200 to 600 g / eq, more preferably 250 to 550 g / eq, and even more preferably 300 to 500 g / eq. The epoxy equivalent in this embodiment can be measured in accordance with JIS K 7236:2009.

[0052] The solid epoxy resin is not particularly limited as long as it is solid at room temperature. Examples include biphenyl-type epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, orthocresol novolac epoxy resin, dicyclopentadiene-type epoxy resin, naphthalene-type epoxy resin, anthracene-type epoxy resin, and fluorene-based epoxy resin. Among these, naphthalene-type epoxy resin, dicyclopentadiene-type epoxy resin, and fluorene-based epoxy resin are preferred, with dicyclopentadiene-type epoxy resin being more preferred. Solid epoxy resins may be used individually or in combination of two or more types. When two or more solid epoxy resins are used, their combination and ratio can be arbitrarily selected.

[0053] The epoxy equivalent of the solid epoxy resin is preferably 150 to 450 g / eq, and more preferably 150 to 400 g / eq.

[0054] The ratio of liquid epoxy resin (xe) to solid epoxy resin (ye) [(xe) / (ye)] is preferably 0.01 to 10.0 by mass, more preferably 0.02 to 8.0, and even more preferably 0.03 to 6.0, from the viewpoint of easily adjusting the complex viscosity at 80°C. When the above ratio [(xe) / (ye)] is within the above range, it is possible to suppress the generation of cutting chips and the like when cutting the cured resin film with a dicing blade after curing, thereby improving processability.

[0055] The number-average molecular weight of the epoxy resin (B1) is not particularly limited, but from the viewpoint of the curability of the thermosetting resin film (x) and the strength and heat resistance of the cured resin film after curing, it is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000.

[0056] -Thermosetting agent (B2)- The thermosetting agent (B2) functions as a curing agent for the epoxy resin (B1). Examples of the thermosetting agent (B2) include compounds having two or more functional groups capable of reacting with epoxy groups in one molecule. Examples of the above functional groups include phenolic hydroxyl groups, alcoholic hydroxyl groups, amino groups, carboxyl groups, and groups in which an acid group has been converted into an anhydride. It is preferable that the functional group is a phenolic hydroxyl group, an amino group, or a group in which an acid group has been converted into an anhydride, and it is more preferable that the functional group is a phenolic hydroxyl group or an amino group.

[0057] Examples of thermosetting agents (B2) that include phenolic curing agents having phenolic hydroxyl groups include polyfunctional phenolic resins, biphenols, novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkylphenolic resins. Among the thermosetting agents (B2), examples of amine-based curing agents having an amino group include dicyandiamide (hereinafter sometimes abbreviated as "DICY"). Among these, phenolic curing agents having phenolic hydroxyl groups are preferred, and novolac-type phenolic resins are more preferred.

[0058] Among the thermosetting agents (B2), the number average molecular weight of the resin components, such as polyfunctional phenolic resins, novolac-type phenolic resins, dicyclopentadiene-based phenolic resins, and aralkylphenolic resins, is preferably 300 to 30,000, more preferably 400 to 10,000, and even more preferably 500 to 3,000. The molecular weight of the non-resin component of the thermosetting agent (B2), such as biphenol or dicyandiamide, is not particularly limited, but is preferably 60 to 500.

[0059] The thermosetting agent (B2) may be used alone or in combination of two or more types. If there are two or more types of thermosetting agent (B2), their combination and ratio can be arbitrarily selected.

[0060] In the thermosetting resin film (x) and thermosetting resin composition (x1), the content of the thermosetting agent (B2) is preferably 0.010 to 200 parts by mass, more preferably 0.020 to 150 parts by mass, even more preferably 0.050 to 100 parts by mass, and even more preferably 0.10 to 77 parts by mass, based on the content of 100 parts by mass of epoxy resin (B1). When the content of the thermosetting agent (B2) is above the lower limit, the curing of the thermosetting resin film (x) proceeds more easily. Furthermore, when the content of the thermosetting agent (B2) is below the upper limit, the moisture absorption rate of the thermosetting resin film is reduced, and the reliability of the package obtained using the thermosetting resin film (x) is further improved.

[0061] In the thermosetting resin film (x) and the thermosetting resin composition (x1), the content of the thermosetting component (B) (total content of epoxy resin (B1) and thermosetting agent (B2)) is preferably 200 to 10,000 parts by mass, more preferably 300 to 5,000 parts by mass, and even more preferably 400 to 1,000 parts by mass, per 100 parts by mass of the polymer component (A), from the viewpoint of enhancing the protective properties of the cured resin film.

[0062] -Curing accelerator (C)- The thermosetting resin film (x) and the thermosetting resin composition (x1) may contain a curing accelerator (C). The curing accelerator (C) is an ingredient used to adjust the curing rate of the thermosetting resin film (x). Preferred curing accelerators (C) include, for example, tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted with groups other than hydrogen atoms); organophosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with organic groups); and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. Among these, imidazoles are preferred, and 2-phenyl-4,5-dihydroxymethylimidazole is more preferred, from the viewpoint of making it easier to exhibit the effects of the present invention.

[0063] The curing accelerator (C) may be used alone or in combination of two or more types. If there are two or more types of curing accelerator (C), their combination and ratio can be arbitrarily selected.

[0064] In the thermosetting resin film (x) and thermosetting resin composition (x1), when a curing accelerator (C) is used, the content of the curing accelerator (C) is preferably 0.001 to 10 parts by mass, and more preferably 0.01 to 5 parts by mass, per 100 parts by mass of the content of the thermosetting component (B). When the content of the curing accelerator (C) is above the lower limit, the effects of using the curing accelerator (C) are more easily obtained. Furthermore, when the content of the curing accelerator (C) is below the upper limit, for example, the effect of suppressing the migration and segregation of highly polar curing accelerators (C) to the adhesive interface side with the adherend in the thermosetting resin film (x) under high temperature and high humidity conditions is enhanced, and the reliability of the package obtained using the thermosetting resin film (x) is further improved.

[0065] -Filling material (D)- The thermosetting resin film (x) and the thermosetting resin composition (x1) may contain a filler (D). The inclusion of filler (D) makes it easier to appropriately adjust the complex viscosity at 80°C. Furthermore, it becomes easier to adjust the coefficient of thermal expansion of the cured resin film obtained by curing the thermosetting resin film (x) to an appropriate range, thereby improving the reliability of the package obtained using the thermosetting resin film (x). Additionally, the inclusion of filler (D) in the thermosetting resin film (x) can reduce the moisture absorption rate of the cured resin film and improve its heat dissipation.

[0066] The filler (D) may be either an organic filler or an inorganic filler, but it is preferably an inorganic filler or an organic / inorganic hybrid filler. Preferred inorganic fillers include, for example, powders such as silica, talc, calcium carbonate, and boron nitride; beads formed from these inorganic fillers in a spherical shape; surface modified products of these inorganic fillers; single crystal fibers of these inorganic fillers; and glass fibers. Preferred organic / inorganic hybrid fillers include, for example, component-mixed fillers such as silica-acrylic composite particles (e.g., Soliostar manufactured by Nippon Shokubai); and composite fillers incorporating inorganic fine particles with organic materials. Among these, inorganic fillers are preferred, and among inorganic fillers, silica is preferred.

[0067] The filler (D) may be used alone or in combination of two or more types. If there are two or more types of filler (D), their combination and ratio can be selected arbitrarily.

[0068] In thermosetting resin films (x) and thermosetting resin compositions (x1), when a filler (D) is used, the content of the filler (D) is preferably 5 to 50% by mass, more preferably 7 to 40% by mass, and even more preferably 10 to 30% by mass, based on the total amount of active ingredients, from the viewpoint of making it easier to appropriately adjust the complex viscosity at 80°C and from the viewpoint of suppressing peeling of the cured resin film from the chip due to thermal expansion and contraction.

[0069] The average particle size of the filler (D) is preferably 500 nm or less, more preferably 5 to 300 nm, and particularly preferably 10 to 100 nm. In this specification, the particle size of the filler (D) refers to the arithmetic mean particle size obtained by randomly selecting and measuring the particle sizes of multiple (e.g., 5) primary particles of the filler (D) observed with an electron microscope, and calculating the average value.

[0070] -Energy ray curable resin (E)- The thermosetting resin film (x) and the thermosetting resin composition (x1) may contain an energy ray curable resin (E). The thermosetting resin film (x) contains an energy-ray curable resin (E), allowing its properties to be altered by irradiation with energy rays.

[0071] Energy-ray curable resin (E) is obtained by polymerizing (curing) an energy-ray curable compound. Examples of energy-ray curable compounds include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth)acryloyl group are preferred.

[0072] Examples of acrylate compounds include chain-like trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples include aliphatic skeleton-containing (meth)acrylates; cyclic aliphatic skeleton-containing (meth)acrylates such as dicyclopentanyl di(meth)acrylate; polyalkylene glycol (meth)acrylates such as polyethylene glycol di(meth)acrylate; oligoester (meth)acrylates; urethane (meth)acrylate oligomers; epoxy-modified (meth)acrylates; polyether (meth)acrylates other than the above-mentioned polyalkylene glycol (meth)acrylates; itaconic acid oligomers, etc.

[0073] The weight-average molecular weight of the energy-ray curable compound is preferably 100 to 30,000, and more preferably 300 to 10,000.

[0074] The energy-ray-curable compound used in polymerization may be used alone or in combination of two or more types. When two or more energy-ray-curable compounds are used in polymerization, their combination and ratio can be arbitrarily selected.

[0075] In thermosetting resin films (x) and thermosetting resin compositions (x1), when an energy-ray curable resin (E) is used, the content of the energy-ray curable resin (E) is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and even more preferably 10 to 85% by mass, based on the total amount of active ingredients in the thermosetting resin composition (x1).

[0076] -Photopolymerization initiator (F)- If the thermosetting resin film (x) and thermosetting resin composition (x1) contain an energy ray curable resin (E), the thermosetting resin film (x) and thermosetting resin composition (x1) may contain a photopolymerization initiator (F) in order to efficiently advance the polymerization reaction of the energy ray curable resin (E).

[0077] Examples of photopolymerization initiators (F) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2-chloroanthraquinone.

[0078] The photopolymerization initiator (F) may be used alone or in combination of two or more types. If there are two or more types of photopolymerization initiator (F), their combination and ratio can be arbitrarily selected.

[0079] In the thermosetting resin film (x) and thermosetting resin composition (x1), when a photopolymerization initiator (F) is used, the content of the photopolymerization initiator (F) is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass, based on 100 parts by mass of the energy ray curable resin (E).

[0080] -Additive (G)- The thermosetting resin film (x) and the thermosetting resin composition (x1) may contain additive (G) as long as the effects of the present invention are not impaired. Additive (G) may be any known additive and can be arbitrarily selected depending on the purpose, and is not particularly limited. Preferred additives (G) include, for example, rheology control agents, coupling agents, crosslinking agents, surfactants, plasticizers, antistatic agents, antioxidants, leveling agents, gettering agents, and silicone oils.

[0081] Additive (G) may be used alone or in combination of two or more types. If there are two or more types of additive (G), their combination and ratio can be arbitrarily selected. The amount of additive (G) is not particularly limited and should be selected as appropriate depending on the purpose.

[0082] -solvent- The thermosetting resin composition (x1) preferably further contains a solvent. The thermosetting resin composition (x1) containing the solvent has good handling properties. The solvent is not particularly limited, but preferred solvents include, for example, hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutyl alcohol (2-methylpropan-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; and amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone. The solvent may be used alone or in combination of two or more types. If two or more solvents are used, their combination and ratio can be arbitrarily selected. The solvent is preferably methyl ethyl ketone or the like, as it allows for more uniform mixing of the components in the thermosetting resin composition (x1).

[0083] -Method for preparing a thermosetting resin composition (x1)- A thermosetting resin composition (x1) is prepared by blending the components that make it up. The order in which each component is added during formulation is not particularly limited, and two or more components may be added simultaneously. When using a solvent, the solvent may be used after pre-diluting the formulation by mixing it with any of the other components, or the solvent may be used by mixing it with the other components without pre-diluting them. The method of mixing each component during formulation is not particularly limited; it can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. The temperature and time during the addition and mixing of each component are not particularly limited as long as the components do not deteriorate, and can be adjusted as appropriate, but a temperature of 15 to 30°C is preferred.

[0084] (Preparation of thermosetting resin film (x)) The thermosetting resin film (x) can be manufactured, for example, by coating the surface to be formed with the thermosetting resin composition (x1) of this embodiment and drying it as necessary. The thermosetting resin composition (x1) may be applied by known methods, such as using various coaters including an air knife coater, blade coater, bar coater, gravure coater, roll coater, roll knife coater, curtain coater, die coater, knife coater, screen coater, Meyer bar coater, and kiss coater. The drying conditions after applying the thermosetting resin composition (x1) are not particularly limited, but for example, the drying temperature can be set to 70 to 130°C and the drying time to 10 seconds to 5 minutes.

[0085] (Requirement (I)) In this embodiment, the thermosetting resin film (x) preferably satisfies the following requirement (I) from the viewpoint of improving the ability to follow irregularities on the circuit-forming surface (α) and the circuit-forming surface (β), and from the viewpoint of making it easier for air bubbles that may form at the interface when the first and second substrates are bonded to escape from the system. Requirement (I): Under conditions of a temperature of 90°C and a frequency of 1Hz, strain is generated in a test specimen of the above thermosetting resin film with a diameter of 25 mm and a thickness of 1 mm, and the storage modulus of the test specimen is measured. When the storage modulus of the test specimen is 1% strain, Gc1 is defined as the storage modulus of the test specimen when the strain is 300%, and Gc300 is defined as the storage modulus of the test specimen when the strain is 300%, the X value calculated by the following formula (i) is less than 10,000. X=Gc1 / Gc300...Formula (i)

[0086] The upper limit of the X value specified in requirement (I) above is preferably 5,000 or less, more preferably 2,000 or less, even more preferably 1,000 or less, even more preferably 500 or less, even more preferably 400 or less, even more preferably 300 or less, even more preferably 100 or less, and particularly preferably 70 or less, from the viewpoint of further improving the ability to follow irregularities on the circuit formation surface (α) and the circuit formation surface (β), and from the viewpoint of making it easier for air bubbles that may form at the interface when the first and second bodies to be bonded to be released from the system. Furthermore, from the viewpoint of making it easier to prevent bleeding when the thermosetting resin film (x) is applied, the lower limit of the X value specified in requirement (I) above is preferably 19 or higher, more preferably 20 or higher, even more preferably 30 or higher, and even more preferably 40 or higher.

[0087] In the thermosetting resin film (x) described above, Gc1 is not particularly limited as long as the X value specified in requirement (I) above is less than 10,000. However, from the viewpoint of making it easier to form a thermosetting resin film (x) with excellent coverage, Gc1 is 1 × 10 2 ~1 × 10 6 It is preferable that it be Pa, which is 2 × 10 3 ~7×10 5 It is more preferable that it be Pa, 3 × 10 3 ~5×10 5 It is even more preferable that it be Pa.

[0088] In the above thermosetting resin film (x), Gc300 is not particularly limited as long as the X value is less than 10,000. However, after the protruding electrode penetrates the thermosetting resin film (x), from the viewpoint of improving the embedding of the thermosetting resin film (x) into the base of the protruding electrode, Gc300 is preferably 10 to 15,000 Pa, more preferably 30 to 10,000 Pa, and even more preferably 60 to 5,000 Pa.

[0089] Furthermore, when adjusting the X value specified in requirement (I) above, it is necessary to adjust the storage modulus of the thermosetting resin film (x). However, the storage modulus of the thermosetting resin film (x) can be easily adjusted not only in the cases of Gc1 and Gc300, but also by adjusting one or both of the types and content of the components contained in the thermosetting resin film (x). To do this, one or both of the types and content of the components contained in the composition for forming the thermosetting resin film (x) should be adjusted. For example, the storage modulus of the thermosetting resin film (x) can be easily adjusted by adjusting one or both of the types and content of the main components, such as polymer components (A) and fillers (D), and by adjusting one or both of the types and content of one or more additives (G) selected from rheology control agents, surfactants, and silicone oils. For example, increasing the content of one or both of the filler (D) and additive (G) in the thermosetting resin film (x) makes it easier to adjust Gc1 to a larger value, and as a result, it becomes easier to adjust the X value to an appropriate value.

[0090] <Structure of a composite sheet> The thermosetting resin film (x) in this embodiment may be a single layer film or may be formed on the release surface of a release film, but from the viewpoint of improving handling and other aspects, it is preferable to be a composite sheet with a support sheet. The following describes the configuration examples of the composite sheet of this embodiment, specifically the first to third embodiments. However, the configuration examples of the composite sheet of this embodiment are not limited to the first to third embodiments. For example, the first to third embodiments may of course have other layers, as long as they do not significantly impair the effects of the present invention.

[0091] (First aspect) Figure 1 shows a first embodiment of the composite sheet of this embodiment. The composite sheet 1a shown in Figure 1 comprises a base material 10 and a thermosetting resin film (x). In the first embodiment, the support sheet is the base material 10. Although not shown, a release film or the like may be provided on the side of the thermosetting resin film (x) opposite to the base material 10.

[0092] (Second aspect) A second embodiment of the composite sheet of this embodiment is shown in Figure 2. The composite sheet 1b shown in Figure 2 comprises a base material 10, a buffer layer 11, and a thermosetting resin film (x) in that order. In the second embodiment, the support sheet is a laminate of the base material 10 and the buffer layer 11. Although not shown, a release film or the like may be provided on the side of the thermosetting resin film (x) opposite to the buffer layer 11.

[0093] (Third aspect) A third embodiment of the composite sheet of this embodiment is shown in Figure 3. The composite sheet 1c of the third embodiment has an intermediate release layer between the buffer layer 11 and the thermosetting resin film (x) in the composite sheet of the second embodiment. That is, as shown in Figure 3, the composite sheet 1c of the third embodiment has a base material 10, a buffer layer 11 laminated on one surface 10a of the base material 10, an intermediate release layer 13 laminated on the surface of the buffer layer 11 opposite to the base material 10, and a thermosetting resin film (x) laminated on the surface of the intermediate release layer 13 opposite to the buffer layer 11. In the second embodiment, the support sheet is a laminate of the base material 10, the buffer layer 11, and the intermediate release layer 13. Although not shown, a release film or the like may be provided on the surface of the thermosetting resin film (x) opposite to the intermediate release layer 13.

[0094] (buffer layer) As described above, the composite sheet of this embodiment may have a buffer layer between the substrate and the thermosetting resin film (x). The buffer layer is a layer that has a buffering effect against forces applied to the buffer layer and layers directly or indirectly adjacent to it. Here, "layers directly or indirectly adjacent to the buffer layer" mainly refers to the thermosetting resin film (x) of this embodiment.

[0095] The buffer layer may consist of only one layer or two or more layers. If the buffer layer consists of multiple layers, these layers may be identical or different from each other, and there are no particular limitations on the combination of these layers.

[0096] The thickness of the buffer layer can be appropriately adjusted according to the height of the protruding electrode provided on at least one of the circuit forming surface (α) and the circuit forming surface (β). However, from the viewpoint of making it easier to exert the effects of the present invention on relatively tall protruding electrodes, it is preferably 100 to 1,000 μm, more preferably 150 to 600 μm, and even more preferably 200 to 400 μm.

[0097] -Storage modulus (G') of the buffer layer at 80°C- In the composite sheet of this embodiment, the storage modulus (G') of the buffer layer at 80°C is preferably 0.08 MPa or higher. If the storage modulus (G') of the buffer layer at 80°C is 0.08 MPa or higher, it becomes easier to ensure the penetration of the protruding electrode into the thermosetting resin film (x), and thus easier to ensure the reliability of the connection between the chip with the protruding electrode and the substrate. Here, from the viewpoint of making it easier to ensure the penetration of the protruding electrode of the thermosetting resin film (x), the storage modulus (G') of the buffer layer at 80°C is more preferably 0.10 MPa or higher, even more preferably 0.12 MPa or higher, even more preferably 0.14 MPa or higher, and still more preferably 0.16 MPa or higher. Furthermore, the storage modulus (G') of the buffer layer at 80°C is preferably 0.4 MPa or less, from the viewpoint of making it easier to adjust the loss tangent (tanδ) of the buffer layer at 80°C (described later) to 1.02 or more, thereby making it easier to ensure the embedding ability of the protruding electrode of the thermosetting resin film (x). The storage modulus (G') of the buffer layer at 80°C refers to the value measured by the method described in the examples below.

[0098] -Loss tangent (tanδ) of the buffer layer at 80°C- In the composite sheet of this embodiment, the loss tangent (tanδ) of the buffer layer at 80°C is preferably 1.02 or greater. If the loss tangent (tanδ) of the buffer layer at 80°C is 1.02 or higher, it is easier to ensure the embedding ability of the thermosetting resin film (x) into the area around the base of the protruding electrode (penetration of the thermosetting resin film (x) into the area around the base of the protruding electrode). Here, from the viewpoint of making it easier to ensure the embedding ability of the protruding electrode of the thermosetting resin film (x), the loss tangent (tanδ) of the buffer layer at 80°C is more preferably 1.05 or higher, even more preferably 1.08 or higher, even more preferably 1.12 or higher, and still most preferably 1.16 or higher. Furthermore, the loss tangent (tanδ) of the buffer layer at 80°C is preferably 2.00 or less, from the viewpoint of making it easier to adjust the storage modulus (G') of the buffer layer at 80°C to 0.08 or higher, thereby making it easier to ensure the penetration of the protruding electrode of the thermosetting resin film (x). The loss tangent (tanδ) of the buffer layer at 80°C refers to the value measured by the method described in the examples below.

[0099] In this embodiment, the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C can be appropriately adjusted by adjusting the composition of the buffer layer, etc. The details of the buffer layer will be explained below, taking into account the method for adjusting the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C.

[0100] -Urethane (meth)acrylate- The buffer layer may contain urethane (meth)acrylate. Urethane (meth)acrylate is a compound having at least a (meth)acryloyl group and a urethane bond, and has the property of polymerizing upon energy ray irradiation. By using urethane (meth)acrylate, flexibility can be provided to the buffer layer, and the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C can be easily adjusted to the above range. The urethane (meth)acrylate may be monofunctional or polyfunctional. In this embodiment, polyfunctional urethane (meth)acrylate is preferred, and bifunctional urethane (meth)acrylate is preferred from the viewpoint of easily adjusting the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C to the above range. The urethane (meth)acrylate may be an oligomer, a polymer, or a mixture thereof. In this embodiment, a urethane (meth)acrylate oligomer is preferred. Urethane (meth)acrylate can be obtained, for example, by reacting a terminal isocyanate urethane prepolymer, which is obtained by reacting a polyol compound with a polyvalent isocyanate compound, with a (meth)acrylate having a hydroxyl group. Note that one or more types of urethane (meth)acrylate may be used. The content of urethane (meth)acrylate in the buffer layer forming composition is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more, from the viewpoint of easily adjusting the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C to the above range. Furthermore, the content of urethane (meth)acrylate in the intermediate layer composition is preferably 70% by mass or less, more preferably 65% ​​by mass or less, and even more preferably 50% by mass or less.

[0101] -Polymerizable monomer- The polymerizable monomer is preferably a polymerizable compound other than the urethane (meth)acrylate mentioned above, and is a compound that can be polymerized with other components by irradiation with energy rays. Specifically, the polymerizable monomer is preferably a compound having at least one (meth)acryloyl group. Examples of polymerizable monomers include (meth)acrylates having alkyl groups with 1 to 30 carbon atoms; (meth)acrylates having functional groups such as hydroxyl groups, amide groups, amino groups, and epoxy groups; (meth)acrylates having an alicyclic structure; (meth)acrylates having an aromatic structure; (meth)acrylates having a heterocyclic structure; and vinyl compounds such as styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N-vinylformamide, N-vinylpyrrolidone, and N-vinylcaprolactam. Examples of (meth)acrylates having alkyl groups with 1 to 30 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, octadecyl (meth)acrylate, and eicosyl (meth)acrylate. Examples of functional group-containing (meth)acrylates include hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, and N-methylol (meth)acrylamide. Examples include amide group-containing compounds such as lylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, and N-butoxymethyl(meth)acrylamide; amino group-containing (meth)acrylates such as primary amino group-containing (meth)acrylates, secondary amino group-containing (meth)acrylates, and tertiary amino group-containing (meth)acrylates; and epoxy group-containing (meth)acrylates such as glycidyl(meth)acrylate, methylglycidyl(meth)acrylate, and allylglycidyl ether. Examples of (meth)acrylates having an alicyclic structure include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxy (meth)acrylate, cyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, and adamantane (meth)acrylate. Examples of (meth)acrylates having an aromatic structure include phenylhydroxypropyl (meth)acrylate, benzyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate. Examples of (meth)acrylates having a heterocyclic structure include tetrahydrofurfuryl(meth)acrylate and morpholine(meth)acrylate. In this embodiment, the polymerizable monomer preferably includes (meth)acrylates having an alkyl group with 1 to 30 carbon atoms and (meth)acrylates having an alicyclic structure. From the viewpoint of easily adjusting the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C to the above range, (meth)acrylates having an alkyl group with 4 to 14 carbon atoms are preferred, and as (meth)acrylates having an alicyclic structure, isobornyl (meth)acrylate and trimethylcyclohexyl (meth)acrylate are preferred. Furthermore, if a buffer layer-forming composition contains a crosslinking agent, (meth)acrylates having functional groups that can react with the crosslinking agent are undesirable. This is because the crosslinked structure formed by the crosslinking reaction may increase the residual stress in the buffer layer. For example, a buffer layer-forming composition containing a polyisocyanate-based crosslinking agent and a (meth)acrylate having hydroxyl groups is undesirable. The content of polymerizable monomers in the buffer layer forming composition is preferably 20% by mass or more, and more preferably 30% by mass or more, from the viewpoint of easily adjusting the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C to the above range. Furthermore, the content of polymerizable monomers in the buffer layer forming composition is preferably 80% by mass or less, and more preferably 70% by mass or less. Furthermore, the mass ratio of urethane (meth)acrylate to polymerizable monomer (urethane (meth)acrylate / polymerizable monomer) in a total of 100 parts by mass of urethane (meth)acrylate and polymerizable monomer is preferably 20 / 80 to 80 / 20, and more preferably 30 / 70 to 70 / 30, from the viewpoint of easily adjusting the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C to the above range.

[0102] -Photopolymerization initiator- When the buffer layer forming composition contains the above-mentioned urethane (meth)acrylate and polymerizable monomer, it is preferable that the buffer layer forming composition also contains a photopolymerization initiator. By including a photopolymerization initiator, polymerization proceeds reliably, and the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C can be easily adjusted to the above range. Examples of photopolymerization initiators include benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds, as well as photosensitizers such as amines and quinones. Specifically, examples include 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and 2,2-dimethoxy-1,2-diphenylethane-1-one. These photopolymerization initiators may be used individually or in combination of two or more. The amount of photopolymerization initiator added is preferably 0.05 parts by mass or more and 15 parts by mass or less, and more preferably 0.5 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the total of urethane (meth)acrylate and polymerizable monomer.

[0103] -Chain Transfer Agent- The buffer layer forming composition preferably contains a chain transfer agent. The chain transfer agent can induce a chain transfer reaction and regulate the progress of the curing reaction of the buffer layer forming composition. By including a chain transfer agent, components with relatively short molecular chains can remain even after curing, so that the cured polymer has a relatively flexible structure. As a result, the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C can be easily adjusted to the above range. Examples of chain transfer agents include thiol group-containing compounds. Examples of thiol group-containing compounds include nonyl mercaptan, 1-dodecanethiol, 1,2-ethanedithiol, 1,3-propanedithiol, triazinethiol, triazinedithiol, triazinetrithiol, 1,2,3-propanetrithiol, tetraethylene glycol-bis(3-mercaptopropionate), trimethylolpropanetris(3-mercaptopropionate), pentaerythritoltetrakis(3-mercaptopropionate), and pentaerythritol. Examples include thritol tetrakisthioglucolate, dipentaerythritol hexakis(3-mercaptopropionate), tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, 1,4-bis(3-mercaptobutyryloxy)butane, pentaerythritol tetrakis(3-mercaptobutyrate), and 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione. The chain transfer agent may be used individually or in combination of two or more types. From the viewpoint of easily adjusting the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C to the above range, the amount of chain transfer agent is preferably 1.0 to 2.5 parts by mass, more preferably 1.2 to 2.0 parts by mass, and even more preferably 1.3 to 1.8 parts by mass, per 100 parts by mass of the total of urethane (meth)acrylate and polymerizable monomer.

[0104] -Other ingredients- The buffer layer may contain other components. These other components are not particularly limited and can be appropriately selected depending on the purpose.

[0105] -Preparation of a buffer layer- As a composition for forming a buffer layer, for example, a buffer layer-forming composition containing the above-mentioned components, or a composition obtained by diluting the buffer layer-forming composition with a solvent or the like, can be prepared. Examples of solvents include organic solvents such as methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, and isopropanol. Then, a buffer layer-forming composition or the like is applied to a release film or substrate by a known method such as spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, or gravure coating to form a coating film, and this coating film is cured to form an intermediate layer on the substrate. In this embodiment, it is preferable to cure the coating film by irradiation with energy rays. Examples of energy rays include ultraviolet rays and electron beams, with ultraviolet rays being preferred. Furthermore, in this embodiment, it is preferable to cure the coating film by irradiating it with energy rays multiple times. By doing so, the degree of curing of the buffer layer can be controlled, and the storage modulus (G') and loss tangent (tanδ) of the buffer layer at 80°C can be easily adjusted to the above range. If the energy source is ultraviolet light, the ultraviolet irradiation conditions are preferably such that the ultraviolet irradiance is 30-500 mW / cm². 2 More preferably 50-340 mW / cm² 2 The ultraviolet radiation dose (cumulative light dose) is preferably 100 to 2,500 mJ / cm². 2 More preferably 150 to 2,000 mJ / cm² 2 That is the case. When irradiating with ultraviolet light multiple times, it is preferable that the illuminance and irradiation dose are greater than those of the previous irradiation. Alternatively, the coated film may be exposed to oxygen and irradiated with energy rays, and then the coated film may be shielded from oxygen and irradiated with energy rays again.

[0106] (Intermediate delamination layer) As described above, the composite sheet of this embodiment may have an intermediate release layer between the buffer layer and the thermosetting resin film (x). The intermediate release layer is provided to easily peel off the buffer layer from the thermosetting resin film (x) after the thermosetting resin film (x) has been attached to the protruding electrode forming surface of the member with protruding electrodes by attaching the composite sheet to the protruding electrode forming surface.

[0107] The intermediate delamination layer is in the form of a sheet or film, and its constituent material is not particularly limited. The intermediate delamination layer preferably contains ethylene-vinyl acetate copolymer (EVA). The intermediate peeling layer may contain other components besides those mentioned above. These other components are not particularly limited and can be appropriately selected depending on the purpose.

[0108] The delamination layer may be a single layer or a multi-layer structure (two or more layers). If the delamination layer consists of multiple layers, these layers may be identical or different, and there are no particular limitations on the combination of these layers.

[0109] The thickness of the interlayer is not particularly limited, but is preferably 5 to 30 μm, more preferably 6 to 25 μm, and even more preferably 7 to 20 μm.

[0110] (base material) The base material is in the form of a sheet or film, and its constituent materials include, for example, the following various resins. Examples of resins constituting the base material include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polyolefins other than polyethylene such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resin; ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-norbornene copolymer (polymers obtained using ethylene as a monomer); and vinyl chloride-based resins such as polyvinyl chloride and vinyl chloride copolymer (using vinyl chloride as a monomer). Examples of resins obtained from this process include: polystyrene; polycycloolefin; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene-2,6-naphthalenedicarboxylate, and all aromatic polyesters having aromatic cyclic groups as all constituent units; copolymers of two or more of the above polyesters; poly(meth)acrylic acid esters; polyurethane; polyurethane acrylate; polyimide; polyamide; polycarbonate; fluororesin; polyacetal; modified polyphenylene oxide; polyphenylene sulfide; polysulfone; polyether ketone; and the like. Furthermore, examples of resins constituting the base material include polymer alloys such as mixtures of the above-mentioned polyester and other resins. It is preferable that the polymer alloy of polyester and other resins contains a relatively small amount of the resin other than polyester. Furthermore, examples of resins constituting the base material include crosslinked resins obtained by crosslinking one or more of the above-mentioned resins; and modified resins such as ionomers using one or more of the above-mentioned resins. The resins that make up the base material may be used individually or in combination of two or more types.

[0111] The base material may consist of only one layer or two or more layers. If the base material consists of multiple layers, these layers may be identical or different from each other, and there are no particular limitations on the combination of these layers.

[0112] The thickness of the substrate is not particularly limited, but is preferably 5 to 1,000 μm, more preferably 10 to 500 μm, even more preferably 15 to 300 μm, and even more preferably 20 to 150 μm.

[0113] The base material should preferably have high thickness accuracy, that is, thickness variation should be suppressed regardless of the location. Among the constituent materials mentioned above, examples of materials with high thickness accuracy that can be used to construct such a base material include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, polybutylene terephthalate, polyesters other than polyethylene terephthalate and polybutylene terephthalate, and ethylene-vinyl acetate copolymers.

[0114] In addition to the main constituent materials such as the resin mentioned above, the base material may also contain various known additives such as fillers, colorants, antioxidants, organic lubricants, catalysts, and plasticizers.

[0115] The substrate may be transparent or opaque, may be colored depending on the purpose, or may have other layers deposited on it.

[0116] The substrate can be manufactured by known methods. For example, a substrate containing a resin can be manufactured by molding a resin composition containing the above-mentioned resin.

[0117] (Method of manufacturing composite sheets) The composite sheet of this embodiment can be manufactured by sequentially stacking the above-mentioned layers in corresponding positional relationships. For example, a composite sheet having a laminated structure of a substrate and a thermosetting resin film (x) can be manufactured by the method shown below. The thermosetting resin composition (x1) of this embodiment is applied to the release surface of the release film, and a thermosetting resin film (x) is formed on the release film by drying as necessary. Next, the substrate and the exposed surface of the thermosetting resin film (x) opposite to the release film are bonded together. This yields a composite sheet having a laminated structure of the substrate and the thermosetting resin film (x). The release film provided on the thermosetting resin film (x) in the composite sheet can be removed at any stage between the time of manufacture of the composite sheet and the time of use. Furthermore, a composite sheet having a laminated structure of a substrate and a thermosetting resin film (x) can also be manufactured by coating one side of the substrate with a thermosetting resin composition (x1) and drying it as necessary.

[0118] Furthermore, for example, a composite sheet having a base material, a buffer layer, and a thermosetting resin film (x) in this order can be manufactured by the method shown below. A buffer layer-forming composition is applied to one surface of a substrate and cured to obtain a first laminated sheet in which the substrate and the buffer layer are laminated together. A release film may be provided on the surface of the buffer layer in the first laminated sheet opposite to the substrate, if necessary. Separately, the thermosetting resin composition (x1) of this embodiment is applied to the release surface of the release film and dried as necessary to form the thermosetting resin composition (x1) on the release film. Next, the exposed surface of the buffer layer in the first laminated sheet opposite to the substrate is bonded to the exposed surface of the thermosetting resin film (x) opposite to the release film. This results in a composite sheet having a structure in which the substrate, buffer layer, thermosetting resin film (x), and release film are laminated in this order. The release film provided on the thermosetting resin film (x) in the composite sheet can be removed at any stage between the time of manufacture of the composite sheet and the time of use.

[0119] A composite sheet comprising layers other than those described above can be manufactured by adding or omitting steps as appropriate in the manufacturing method described above, so that the stacking positions of each layer are at desired positions.

[0120] [Details of the manufacturing method of the semiconductor device according to this embodiment] The details of each step in the semiconductor device manufacturing method of this embodiment will be described below. In the following explanation, we will use the example where both the first and second members are semiconductor chips with protruding electrodes on their circuit-forming surfaces. However, as previously mentioned, the first and second members are not limited to these, and may be substrates with wiring on their circuit-forming surfaces, or substrates with protruding electrodes on their circuit-forming surfaces.

[0121] <Step (S1): Preparation process for the first and second objects to be bonded> In step (S1), the circuit-forming surface (α) of the first member and the circuit-forming surface (β) of the second member are each given a complex viscosity of 1 × 10 at 80°C. 4 Prepare a first and a second workpiece, each having a thermosetting resin film (x) with a curing rate of less than Pa·s attached, and at least one of the thermosetting resin films (x) being in an uncured state.

[0122] The following describes in detail the application process (S11) carried out in process (S1), the removal process (S12) which may be carried out in process (S1), the head-exposing process (S13), the individualization process (S14), and the curing process (S15). In step (S1), the procedure for fabricating the first bonded object using a semiconductor wafer having a circuit formation surface (α) will be described. However, since the procedure for fabricating the second bonded object using a semiconductor wafer having a circuit formation surface (β) is almost the same, the explanation of the procedure for fabricating the second bonded object will be omitted. Furthermore, the following explanation will use the case where composite sheet 1b is used as an example, but of course, composite sheets 1a or 1c for forming protective films may also be used, or a thermosetting resin film (x) may be directly applied as a single layer.

[0123] (Process (S11): Pasting process) Figure 4 is a schematic cross-sectional view illustrating the application process. Figures 4(a) and (b) show the process of attaching the composite sheet 1a to the circuit formation surface (α) of the semiconductor wafer 20. In the bonding process, for example, first, as shown in Figure 4(a), the composite sheet 1a is positioned so that the thermosetting resin film (x) faces the circuit formation surface (α) of the semiconductor wafer 20. Next, the thermosetting resin film (x) is brought into contact with the protruding electrode 21 on the semiconductor wafer 20, and the composite sheet 1a is pressed against the semiconductor wafer 20. By pressing, the thermosetting resin film (x) is sequentially pressed onto the surface of the protruding electrode 21 and the circuit formation surface (α) of the semiconductor wafer 20. When the composite sheet 1a is pressed onto the semiconductor wafer 20, the thermosetting resin film (x) is subjected to pressure from the protruding electrode 21 through the buffer layer 11, causing tearing in the thermosetting resin film (x). Finally, as shown in Figure 4(b), the top of the protruding electrode 21 penetrates the thermosetting resin film (x) and protrudes. Furthermore, from the viewpoint of ensuring that the top of the protruding electrode 21 penetrates and protrudes from the thermosetting resin film (x), as described above, it is preferable that the storage modulus (G') of the buffer layer at 80°C is 0.10 MPa or higher. Also, from the viewpoint of improving bump embedding performance, as described above, it is preferable that the loss tangent (tanδ) of the buffer layer at 80°C is 1.05 or higher.

[0124] The height of the protruding electrode 21 is not particularly limited, but is preferably 10 to 300 μm, more preferably 20 to 200 μm, and even more preferably 30 to 100 μm. In this specification, "height of the protruding electrode" means the height of the protruding electrode 21 at the highest position relative to the circuit formation surface.

[0125] The width of the protruding electrode 21 is not particularly limited, but is preferably 5 to 200 μm, more preferably 10 to 100 μm, and even more preferably 10 to 50 μm. In this specification, "width of the protruding electrode" means the maximum length of a line segment obtained by drawing a straight line between two different points on the surface of the protruding electrode when viewed from above in a plan view from a direction perpendicular to the circuit formation surface.

[0126] The distance between adjacent protruding electrodes 21 is not particularly limited, but is preferably 30 to 800 μm, more preferably 40 to 500 μm, and even more preferably 50 to 200 μm. In this specification, "distance between adjacent protruding electrodes" means the minimum distance between the surfaces of adjacent protruding electrodes.

[0127] As a method for pressing the composite sheet 1a onto the semiconductor wafer 20, known methods for pressing and attaching various sheets to an object can be applied, such as using a roller-type laminator. The heating temperature when pressing the composite sheet 1a onto the semiconductor wafer 20 is not particularly limited and may be, for example, 80 to 100°C, and preferably 85 to 95°C. The pressure applied when pressing the composite sheet 1a onto the semiconductor wafer 20 is not particularly limited and may be, for example, 0.1 to 1.5 MPa, and preferably 0.3 to 1 MPa. The speed at which the composite sheet 1a is attached to the semiconductor wafer 20 is not particularly limited, and is usually around 2 to 3 mm / s.

[0128] After the bonding process, the side of the semiconductor wafer 20 opposite to the circuit formation surface (α) (the back side) may be ground as needed, and another sheet (not shown) may be attached to the back side after grinding.

[0129] (Step (S12): Removal step) When a thermosetting resin film (x) is applied using a composite sheet, a removal step (S12) is required. Figure 5 is a schematic cross-sectional view illustrating the removal step. After the bonding process, as shown in Figure 5, layers other than the thermosetting resin film (x) (support sheet) are removed from the composite sheet 1b to obtain a semiconductor wafer with a thermosetting resin film (x), which comprises a semiconductor wafer 20 and a thermosetting resin film (x) provided on the circuit formation surface (α) of the semiconductor wafer 20. The layers other than the thermosetting resin film (x) (support sheet) can be removed by known methods.

[0130] (Process (S13): Heading process) If the top of the protruding electrode 21 is covered with a thermosetting resin film (x), or if there is residue on the top of the protruding electrode 21, it is preferable to perform a head-exposure step (S13) to expose the top of the protruding electrode 21. One or more processing methods selected from plasma processing methods and laser irradiation methods can be used to perform the head-exposure step (S13).

[0131] (Process (S14): singulation process) Figure 6 is a schematic cross-sectional view illustrating the individualization process. After the above process, as shown in Figure 6, in the individualization process, the thermosetting resin film (x) is cut from the side using a dicing blade, and the thermosetting resin film (x) and the semiconductor wafer 20 are cut together. As a result, a semiconductor chip 60 with a cured resin film is obtained as the first component, in which the cut thermosetting resin film (x) is attached to the bump-forming surface of the semiconductor chip 50.

[0132] It should be noted that the individualization step (S14) is not mandatory, and if the first and second joined parts of the desired size can be obtained without performing the individualization step (S14), the individualization step (S14) may be omitted.

[0133] (Process (S15): hardening process) After the above steps, the thermosetting resin film (x) may be thermally cured to form a cured resin film (x)' on the circuit formation surface (α) of the semiconductor wafer 20. This results in a semiconductor wafer 40 with a cured resin film (x)' on the circuit formation surface (α) of the semiconductor wafer 20. The conditions for thermosetting the thermosetting resin film (x) are not particularly limited and can be appropriately adjusted and determined depending on the type of material constituting the thermosetting resin film (x). In step (S1), a first and second workpiece are prepared in which at least one of the thermosetting resin films (x) is in an uncured state. Therefore, at least one of the thermosetting resin films (x) of the first and second workpieces must remain in an uncured state without being heat-cured in step (S1). Preferably, both the thermosetting resin films (x) of the first and second workpieces are left in an uncured state in step (S1).

[0134] <Step (S2): Temporary joined body production process> In step (S2), as shown in Figure 7, the circuit-forming surface (α) of the first object to be joined and the circuit-forming surface (β) of the second object to be joined are brought into opposing contact and bonded to obtain a temporary joint. The first object to be joined and the second object to be joined have a thermosetting resin film (x) attached to at least one of them, which is in an uncured state. The thermosetting resin film (x) in an uncured state has tack, which has the advantage of allowing the first object to be joined and the second object to be joined to be easily temporarily joined. Therefore, after the first object to be joined and the second object to be joined are properly aligned so that they can be electrically connected, this state can be temporarily fixed, preventing misalignment in subsequent processes and improving alignment accuracy.

[0135] In step (S2), it is preferable to remove the metal oxide film from the top of the protruding electrode before performing temporary bonding. Conventional known methods for removing the metal oxide film include applying a flux. Here, from the viewpoint of eliminating the effort of applying flux and making the manufacturing of semiconductor devices simpler, it is preferable that the flux is incorporated into the thermosetting resin film (x) (in other words, that the flux is incorporated into the thermosetting resin composition (x1)).

[0136] (Flux agent (H)) As the flux (H), any flux that has been conventionally used to remove metal oxide films during mounting can be used as appropriate. Examples of fluxing agents (H) include carboxylic acids, rosin derivatives, nitrogen-containing compounds, phenols, and alcohols. Among these, carboxylic acids and rosin esters are preferred. Examples of carboxylic acids include malonic acid, succinic acid, maleic acid, glutaric acid, suberic acid, adipic acid, and sebacic acid. Furthermore, abietic acid and the like can be used as rosin derivatives. In addition, for example, Pine Crystal KE-604, Pine Crystal KR-120, and Pine Crystal KR-140 manufactured by Arakawa Chemical Industries, Ltd. can also be used as rosin derivatives. Here, from the viewpoint of forming a thermosetting resin film (x), it is preferable to use a rosin derivative (such as a rosin ester), which is a highly viscous fluxing agent. Furthermore, from the viewpoint of making it easier to suppress acid degradation of the cured resin film obtained by curing the thermosetting resin film (x), it is also preferable to use a rosin derivative (such as a rosin ester). This is because rosin derivatives are fluxing agents that are not very acidic, and therefore they make it easier to suppress acid degradation of the cured resin film obtained by curing the thermosetting resin film (x).

[0137] From the viewpoint of ensuring sufficient electrical connection reliability, the content of fluxing agent (H) is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1.0 parts by mass or more, even more preferably 1.5 parts by mass or more, and still more preferably 2.0 parts by mass or more, based on 100 parts by mass of the total solid content in the thermosetting resin film (x) excluding the fluxing agent (H). Furthermore, the content of the fluxing agent (H) is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the total solid content in the thermosetting resin film (x) excluding the fluxing agent (H), in order to make it easier to suppress bleeding when the thermosetting resin film (x) is applied.

[0138] The thermosetting resin film (x) of this embodiment can be formed by blending a fluxing agent (H) with the thermosetting resin composition (x1) described above and molding it into a film. Here, in the thermosetting resin film (x) of this embodiment, the meaning of "containing fluxing agent (H)" is not limited to the embodiment in which the fluxing agent (H) is uniformly dispersed within the thermosetting resin film (x), and the fluxing agent (H) may be non-uniformly dispersed within the thermosetting resin film (x). For example, the fluxing agent (H) may have a concentration gradient in the thickness direction of the thermosetting resin film (x), in which case it is preferable that the concentration gradient is such that the concentration of fluxing agent (H) is higher on the surface of the thermosetting resin film (x) opposite to the surface in contact with the protruding electrode forming surface. Furthermore, the flux agent (H) may be dispersed on the surface of the thermosetting resin film (x) opposite to the surface in contact with the protruding electrode forming surface, or a layer of flux agent (H) may be formed on the surface opposite to the surface in contact with the protruding electrode forming surface. In this embodiment, such a configuration in which the flux agent (H) is retained in the thermosetting resin film (x) is also included in the phrase "contains flux agent (H)".

[0139] <Process (S3): Joint fabrication process> In step (S3), as shown in Figure 8, the complex viscosity of the uncured thermosetting resin film (x) of the temporary joint is 1 × 10⁻⁶. 4 After heating to a temperature below Pa·s, the temperature is further increased to heat-cur the thermosetting resin film (x) and obtain a bonded body. This makes it possible to expel air bubbles that enter the bonding surface in step (S2) as shown in Figure 7. The first and second objects to be joined are each covered with a thermosetting resin film (x) in which at least one is in an uncured state. Therefore, by heating in step (S3), the protruding electrodes of the first and second objects to be joined are electrically connected well, and the thermosetting resin film (x) is thermally crosslinked throughout, including the bonding interface, to form an extremely strong bond. Furthermore, since the protruding electrodes are protected by a thermosetting resin film (x), the shape of the protruding electrodes can be easily maintained without deformation. Therefore, it is possible to prevent short circuits between adjacent electrodes and ensure electrical connection reliability. Furthermore, the complex viscosity of the uncured thermosetting resin film (x) is 1 × 10⁻⁶. 4 By heating the thermosetting resin film (x) to a temperature below Pa·s, the flexibility and fluidity of the film temporarily increase, making it easier for the films to adhere more closely to each other at the bonding surface. As a result, air bubbles that have entered the bonding surface are more easily expelled from the system. Therefore, the incorporation of air bubbles into the bonding surface is suppressed. This allows for a better bonding state. Furthermore, even if foreign matter is incorporated into the bonding interface between the first and second bonded bodies, such foreign matter will be incorporated into the thermoset product of the thermosetting resin film (x). Therefore, the reliability of the electrical connection will not be significantly impaired due to the influence of such foreign matter. Here, the heating of the uncured thermosetting resin film (x) is preferably performed when the complex viscosity of the thermosetting resin film (x) is 5 × 10, from the viewpoint of improving the effects of the present invention. 3 Pa·s or less, futur2×10 3 Pa·s or less, more preferably 1.2 × 10 3 It is preferable to carry out the procedure within a range of Pa·s or less. Furthermore, from the viewpoint of the stability of the thermosetting resin film (x), the complex viscosity of the thermosetting resin film (x) is preferably 1.0 × 10 2 Pa·s or higher, more comfortable 1.3 × 10 2 Pa·s or more, more preferably 1.5 × 10 2 It is preferable to perform the procedure within the range of Pa·s or higher. Specifically, the heating conditions (first firing conditions) are preferably set to a temperature range of 60°C to less than 100°C for 10 minutes to 2 hours. Typical heat curing conditions (second firing conditions) are 100°C to 200°C for 1 to 5 hours.

[0140] In the above-described method for manufacturing a semiconductor device, we have explained the case where both the first and second components are semiconductor chips with protruding electrodes on their circuit-forming surfaces. However, for example, the first component may be a substrate with protruding electrodes on its circuit-forming surface, and the second component may be a substrate with wiring on its circuit-forming surface. In this case as well, a temporary bond as shown in Figure 9 can be obtained by the same process as described above, and a bonded body can be obtained by performing the subsequent process (S3). [Examples]

[0141] The present invention will be specifically described by the following examples, but the present invention is not limited to these examples. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or other reasons, measurements can be taken using other instruments with equivalent performance.

[0142] [Manufacturing of composite sheets comprising a thermosetting resin film (x)] A composite sheet comprising a thermosetting resin film (x) was manufactured by the method described below.

[0143] <Raw materials for thermosetting resin composition (x1)> The raw materials used in the production of the thermosetting resin composition (x1) are shown below. "Polymer component (A)" (A)-1: Polyvinyl butyral having constituent units represented by the following formulas (i)-1, (i)-2, and (i)-3 (Sekisui Chemical Co., Ltd. "S-Rec BL-10", weight-average molecular weight 25,000, glass transition temperature 59°C). [ka] (In the formula, l is approximately 28, m is between 1 and 3, and n is an integer between 68 and 74.) "Epoxy resin (B1)" (B1)-1: Liquid modified bisphenol A type epoxy resin (DIC Corporation's "Epiclon EXA-4850-150", number average molecular weight 900, epoxy equivalent 450 g / eq) (B1)-2: Dicyclopentadiene type epoxy resin (DIC Corporation's "Epiclon HP-7200HH", epoxy equivalent 254-264 g / eq) "Thermosetting agent (B2)" (B2)-1: O-cresol type novolac resin (DIC Corporation's "Phenolite KA-1160") "Curing accelerator (C)" (C)-1:2-phenyl-4,5-dihydroxymethylimidazole (Shikoku Chemicals Co., Ltd. "Curesol 2PHZ-PW") "Filling material (D)" (D)-1: Spherical silica modified with epoxy groups (Admanano YA050C-MKK, manufactured by Admatex, with an average particle size of 50 nm) "Additives (G)" (G)-1: Surfactant (acrylic polymer, BYK Corporation's "BYK-361N") (G)-2: Silicone oil (aralkyl-modified silicone oil, "XF42-334" manufactured by Momentive Performance Materials Japan) "Flux agent (H)" (H)-1: Manufactured by Arakawa Chemical Industries, Ltd., product name "Pine Crystal KE-604", rosin derivative (H)-2: Manufactured by Arakawa Chemical Industries, Ltd., product name "Pine Crystal KR-120", rosin derivative (H)-3: Manufactured by Arakawa Chemical Industries, Ltd., product name "Pine Crystal KR-140", rosin derivative (H)-4: Succinic acid (H)-5: Adipic acid

[0144] <Manufacturing Example 1: Preparation of Thermosetting Resin Film (x)-1 and Composite Sheet (X)-1> (Preparation of thermosetting resin film (x)-1) Polymer component (A)-1 (100 parts by mass), epoxy resin (B1)-1 (290 parts by mass), epoxy resin (B1)-2 (220 parts by mass), (B2)-1 (160 parts by mass), curing accelerator (C)-1 (2 parts by mass), filler (D)-1 (200 parts by mass), additive (G)-1 (25 parts by mass), and additive (G)-2 (3 parts by mass) were blended, and flux agent (H)-1 was further added. The mixture was dissolved or dispersed in methyl ethyl ketone and stirred at 23°C to obtain a thermosetting resin composition in which the total concentration of all components other than the solvent was 45% by mass. Note that all amounts of components other than the solvent shown herein are the amounts of the target product without the solvent. Furthermore, the amount of flux agent (H)-1 added was 5 parts by mass per 100 parts by mass of the total solid content excluding the flux agent. Next, the thermosetting resin composition obtained above was applied to the release surface of a release film (Lintec Corporation's "SP-PET1031"), and dried at 120°C for 1 minute to produce a thermosetting resin film (x)-1 with a thickness of 30 μm on the release film. Furthermore, a composite sheet (X)-1 having a layered structure of release film / thermosetting resin film (x)-1 / substrate was fabricated by laminating a polyethylene multilayer sheet (Gunze Corporation's "Funclear LLB type #110", 110 μm thick) as a base material to a thermosetting resin film (x)-1 with a thickness of 30 μm on a release film.

[0145] <Manufacturing Example 2: Preparation of Thermosetting Resin Film (x)-2 and Composite Sheet (X)-2> A thermosetting resin film (x)-2 with a thickness of 30 μm and a composite sheet (X)-2 comprising the thermosetting resin film (x)-2 were prepared by the same method as in Production Example 1, except that flux agent (H)-1 was changed to flux agent (H)-2 and the amount of flux agent (H)-2 was changed to 10 parts by mass.

[0146] <Manufacturing Example 3: Preparation of Thermosetting Resin Film (x)-3 and Composite Sheet (X)-3> A thermosetting resin film (x)-3 with a thickness of 30 μm and a composite sheet (X)-3 comprising the thermosetting resin film (x)-3 were prepared using the same method as in Production Example 1, except that flux agent (H)-1 was changed to flux agent (H)-3.

[0147] <Manufacturing Example 4: Preparation of Thermosetting Resin Film (x)-4 and Composite Sheet (X)-4> Except for changing flux agent (H)-1 to flux agent (H)-4 and changing the amount of flux agent (H)-4 to 2 parts by mass, a thermosetting resin film (x)-4 with a thickness of 30 μm and a composite sheet (X)-4 comprising the thermosetting resin film (x)-4 were prepared by the same method as in Production Example 1.

[0148] <Manufacturing Example 5: Preparation of Thermosetting Resin Film (x)-5 and Composite Sheet (X)-5> A thermosetting resin film (x)-5 with a thickness of 30 μm and a composite sheet (X)-5 comprising the thermosetting resin film (x)-5 were prepared by the same method as in Production Example 1, except that flux agent (H)-1 was changed to flux agent (H)-5 and the amount of flux agent (H)-5 was changed to 2 parts by mass.

[0149] <Manufacturing Example 6: Preparation of Thermosetting Resin Film (x)-6 and Composite Sheet (X)-6> Without incorporating a fluxing agent (H), a thermosetting resin film (x)-6 with a thickness of 30 μm and a composite sheet (X)-6 comprising the thermosetting resin film (x)-6 were prepared by the same method as in Production Example 1.

[0150] <Manufacturing Example 7: Preparation of Thermosetting Resin Film (x)-7 and Composite Sheet (X)-7> A thermosetting resin film (x)-7 with a thickness of 45 μm and a composite sheet (X)-7 comprising the thermosetting resin film (x)-7 were prepared by the same method as in Production Example 1, except that the amount of coating of the thermosetting resin composition was changed.

[0151] <Manufacturing Example 8: Preparation of Thermosetting Resin Film (x)-8 and Composite Sheet (X)-8> A thermosetting resin film (x)-8 with a thickness of 60 μm and a composite sheet (X)-8 comprising the thermosetting resin film (x)-8 were prepared by the same method as in Production Example 1, except that the amount of thermosetting resin composition applied was changed.

[0152] <Manufacturing Example 9: Preparation of Thermosetting Resin Film (x)-9 and Composite Sheet (X)-9> The formulation of the thermosetting resin composition was modified by changing the filler (D) to 640 parts by mass, and a thermosetting resin film (x)-9 with a thickness of 30 μm and a composite sheet (X)-9 comprising the thermosetting resin film (x)-9 were prepared by the same method as in Production Example 1.

[0153] <Manufacturing Example 10: Preparation of Thermosetting Resin Film (x)-10 and Composite Sheet (X)-10> The formulation of the thermosetting resin composition was modified by changing the filler (D) to 40 parts by mass, and a thermosetting resin film (x)-10 with a thickness of 30 μm and a composite sheet (X)-10 comprising the thermosetting resin film (x)-10 were prepared by the same method as in Production Example 1.

[0154] [Examples 1-9 and Comparative Examples 1-11] In Examples 1-9 and Comparative Examples 1-11, thermosetting resin films were used in the following combinations, and the evaluations described later were carried out. Although Examples 1-8 and Comparative Examples 1-8 use the same combination, Examples 1-8 involve two firings after temporary joining, while Comparative Examples 1-8 involve only one firing after temporary joining. Example 1: Thermosetting resin film (x)-1 (uncured) and thermosetting resin film (x)-1 (uncured) • Example 2: Thermosetting resin film (x)-1 (thermosetting) and thermosetting resin film (x)-1 (uncured) Example 3: Thermosetting resin film (x)-2 (uncured) and thermosetting resin film (x)-2 (uncured) • Example 4: Thermosetting resin film (x)-3 (uncured) and thermosetting resin film (x)-3 (uncured) • Example 5: Thermosetting resin film (x)-4 (uncured) and thermosetting resin film (x)-4 (uncured) • Example 6: Thermosetting resin film (x)-5 (uncured) and thermosetting resin film (x)-5 (uncured) Example 7: Thermosetting resin film (x)-6 (uncured) and thermosetting resin film (x)-6 (uncured) • Example 8: Thermosetting resin film (x)-7 (uncured) and thermosetting resin film (x)-7 (uncured) Example 9: Thermosetting resin film (x)-10 (uncured) and thermosetting resin film (x)-10 (uncured) Comparative Example 1: Thermosetting resin film (x)-1 (uncured) and thermosetting resin film (x)-1 (uncured) Comparative Example 2: Thermosetting resin film (x)-1 (thermosetting) and thermosetting resin film (x)-1 (uncured) Comparative Example 3: Thermosetting resin film (x)-2 (uncured) and thermosetting resin film (x)-2 (uncured) Comparative Example 4: Thermosetting resin film (x)-3 (uncured) and thermosetting resin film (x)-3 (uncured) Comparative Example 5: Thermosetting resin film (x)-4 (uncured) and thermosetting resin film (x)-4 (uncured) Comparative Example 6: Thermosetting resin film (x)-5 (uncured) and thermosetting resin film (x)-5 (uncured) Comparative Example 7: Thermosetting resin film (x)-6 (uncured) and thermosetting resin film (x)-6 (uncured) Comparative Example 8: Thermosetting resin film (x)-7 (uncured) and thermosetting resin film (x)-7 (uncured) Comparative Example 9: Thermosetting resin film (x)-9 (uncured) and thermosetting resin film (x)-9 (uncured) Comparative Example 10: Thermosetting resin film (x)-1 (thermosetting) and thermosetting resin film (x)-1 (thermosetting) • Comparative Example 11: Thermosetting resin film (x)-8 (uncured) only

[0155] [evaluation] Shear strength, conductivity, and seepage properties were evaluated using the methods described below.

[0156] <Evaluation of shear force> A roller-type laminator (Lintec Corporation, product name "RAD-3520 F / 12") was used as the lamination device, and the thermosetting resin film (x) side of the composite sheet (X) was attached to the mirror surface of a mirror wafer (8 inches, 250 μm thick) under the following lamination conditions, and the support sheet (substrate) was peeled off. (Attachment conditions) • Table temperature: 90℃ • Application speed: 3m / s • Adhesion pressure: 0.5 MPa • Roller application height: 0 μm Next, the mirror wafer with the thermosetting resin film (x) attached was cut into 2cm x 2cm and 3cm x 3cm squares to produce chips with the thermosetting resin film (x) attached. Then, using a bonding apparatus (Toray Engineering's "FC-3000W"), the thermosetting resin film (x) of a chip with a 2cm x 2cm thermosetting resin film (x) and the thermosetting resin film (x) of a chip with a 3cm x 3cm thermosetting resin film (x) were brought into contact in a desired combination (for example, in Example 1, a combination of thermosetting resin film (x)-1 (uncured) and thermosetting resin film (x)-1 (uncured)) to temporarily bond them, and then thermocured. The temporary joining conditions were a load of 10N and a pressing time of 1 second. The firing conditions (thermosetting conditions) for Examples 1-9 and Comparative Example 9 were 90°C for 1 hour followed by 130°C for 4 hours. For Comparative Examples 1-8 and Comparative Examples 10-11, only 130°C for 4 hours of heating was performed, without the 90°C for 1 hour step. All heating was carried out without pressure. In addition, when using a pre-cured thermosetting resin film (x), as in Example 2 and Comparative Example 10 (thermosetting resin film (x)-1 (thermosetting)), the thermosetting resin film (x) was thermo-cured at 130°C for 4 hours before bonding. The shear force was then measured using the following method. Using a bond tester (Dage Series 4000), a force was applied at a speed of 200 μm / s in a direction parallel to one side of the cured resin film of the thermosetting film (x) obtained in the test specimen, at a aligned portion of the side of the cured resin film. At this time, a stainless steel plate-shaped means was used as the pressing means for applying the force, and the height of the tip of the pressing means was adjusted to half the sum of the tip thickness and the cured resin film thickness (for example, 250 μm + 30 μm in the case of Example 1) so that the pressing means was in contact with the cured resin film alone. The maximum force applied until the cured resin film was destroyed or peeled off at the bonding surface was measured, and this measured value was adopted as the shear strength (N) of the cured resin film. The greater the shear force, the greater the bonding strength between the cured resin films, which are the thermoset products of the thermosetting resin film (x), meaning that the two chips are firmly bonded together. In this example, a shear force of 10N or more was considered acceptable.

[0157] <Evaluation of conductivity> A roller-type laminator (Lintec Corporation, product name "RAD-3520 F / 12") was used as the lamination device, and under the following lamination conditions, the thermosetting resin film (x) side of the composite sheet was attached to the protruding electrode formation surface of a semiconductor wafer having protruding electrodes, and the support sheet (a laminate of the substrate, buffer layer, and intermediate release layer) was peeled off. (Attachment conditions) • Table temperature: 90℃ • Application speed: 3m / s • Adhesion pressure: 0.5 MPa • Roller application height: 0 μm (Specifications of semiconductor wafers with protruding electrodes) • Wafer size: 8 inches • Wafer thickness: 250 μm • Height of protruding electrode: 40 μm ·Distance between protruding electrodes: 100μm • Types of protruding electrodes: Pillar electrodes (electrodes in which a tin-silver solder plating is applied to the top of a columnar-shaped copper column.) Furthermore, when using thermosetting resin films (x)-1 to (x)-9, no leakage of the thermosetting resin film was observed on the edges of the semiconductor wafer after application using the application device.

[0158] Next, the semiconductor wafer with the thermosetting resin film (x) attached was cut into 5mm x 5mm pieces, and chips with the thermosetting resin film (x) attached were fabricated so that there were 144 protruding electrodes per chip. Then, using a bonding device (Toray Engineering's "FC-3000W"), the thermosetting resin films (x) of two 5mm x 5mm thermosetting resin films (x) attached to a chip were brought into contact with each other in a desired combination (for example, in Example 1, a combination of thermosetting resin film (x)-1 (uncured) and thermosetting resin film (x)-1 (uncured)) to temporarily bond them, and then thermocured. The temporary joining conditions were a load of 10N and a pressing time of 1 second. The thermosetting conditions for Examples 1-9 and Comparative Example 9 were heating at 90°C for 1 hour followed by heating at 130°C for 4 hours. For Comparative Examples 1-8 and Comparative Examples 10-11, only heating at 130°C for 4 hours was performed, without the 1-hour heating at 90°C. In addition, when using a pre-cured thermosetting resin film (x)-1, as in Example 2 and Comparative Example 1, the thermosetting resin film (x) was heat-cured at 130°C for 4 hours before bonding. Furthermore, in Example 7, which used thermosetting resin film (x)-6 without flux (a combination of thermosetting resin film (x)-6 (uncured) and thermosetting resin film (x)-6 (uncured)), a flux (succinic acid) was applied to the surface of the thermosetting resin film (x)-6 where the protruding electrodes were exposed, then the above-mentioned temporary bonding was performed and the film was thermocured. Furthermore, in Example 8, which used thermosetting resin film (x)-7 with a film thickness of 45 μm (combination of thermosetting resin film (x)-7 (uncured) and thermosetting resin film (x)-7 (uncured)), since the protruding electrodes were not exposed after the application of thermosetting resin film (x)-7, the surfaces of both chips to which thermosetting resin film (x)-7 was applied were polished using a surface planer to expose the protruding electrodes, and then the above-mentioned temporary bonding was performed and thermocured. Then, a continuity test was performed using a tester (HIOKI "3244 CARD HiTESTER"). A test was deemed to pass (A) if the resistance value was less than ±20% from the blank, and to fail (B) if the resistance value changed by more than ±20% from the blank. Note that if a test is connected to an adjacent protruding electrode, a shortcut occurs in the path, causing the resistance value to decrease. Also, if a crack develops in the protruding electrode, the conductive area decreases, causing the resistance value to increase.

[0159] <Measurement of Gc1 and Gc300 of thermosetting resin film (x), and calculation of X value> A thermosetting resin film (x)-1 with a thickness of 30 μm was prepared in the same manner as in Production Example 1, except that the amount of thermosetting resin composition (x1)-1 applied was changed. Next, the thermosetting resin films (x)-1 were laminated, and the resulting laminated films were cut into discs with a diameter of 25 mm to prepare test specimens of thermosetting resin film (x)-1 with a thickness of 1 mm. In the viscoelasticity measuring device (Anton Paar's "MCR301"), the location where the test specimen was to be placed was preheated to 90°C. The test specimen obtained above was then placed on this location, and the test specimen was fixed to the location by pressing a measuring jig against its upper surface. Next, under conditions of a temperature of 90°C and a measurement frequency of 11Hz, the strain generated in the test specimen was gradually increased in the range of 0.01% to 1000%, and the storage modulus Gc of the test specimen was measured. Then, the X value was calculated from the measured values ​​of Gc1 and Gc300. The same measurements were performed on thermosetting resin films (x)-2 to (x)-10.

[0160] Furthermore, in the conductivity evaluation, the chips with the fabricated thermosetting resin film (x) were heated at 130°C for 4 hours to heat-cur the thermosetting resin film (x). The chips were then observed through the cured resin film using a digital microscope (Keyence VHX-7000) at 100x magnification. The observation area was 2cm x 2cm in the center of the semiconductor wafer. The chips were then evaluated according to the following criteria, with evaluation A being considered a pass. Evaluation A: No air bubbles were generated between the circuit formation surface and the cured resin film, and the unevenness was successfully filled in. Evaluation B: Air bubbles have formed between the circuit formation surface and the cured resin film, and the unevenness has not been properly filled.

[0161] <Measurement of complex viscosity, evaluation of air bubble inclusion at the bonding surface (interface between cured resin films)> A thermosetting resin film (x)-1 with a thickness of 30 μm was prepared in the same manner as in Production Example 1, except that the amount of thermosetting resin composition (x1)-1 applied was changed. Next, the thermosetting resin films (x)-1 were laminated, and the resulting laminated films were cut into discs with a diameter of 25 mm to prepare test specimens of thermosetting resin film (x)-1 with a thickness of 1 mm. The sample was placed in a viscoelasticity measuring device (Anton Paar "MCR301"). The sample was fixed in place by placing it on the device's mounting location and pressing a measuring jig against its upper surface. The complex viscosity was then measured at intervals from room temperature to 150°C under the following measurement conditions: frequency: 11 Hz, heating rate: 10°C / min, and applied strain: 0.1%. The complex viscosity at 80°C was then determined. The same measurements were performed on thermosetting resin films (x)-2 to (x)-10.

[0162] In the conductivity evaluation, the chip side of one side of the fabricated bond was polished using a cross-sectional polishing machine (Refine Polisher HV, manufactured by Refine Tech Co., Ltd.) to expose the cured resin film. Next, the exposed surface of the cured resin film was observed through the cured resin film under a digital microscope (manufactured by KEYENCE, VHX-7000) at a magnification of 100 times. The observation area was set to 2 cm × 2 cm of the chip size. The evaluation criteria were as follows. In this example, evaluation A was regarded as passing. · Evaluation A: No bubbles are generated on the bonding surface (interface between the cured resin films). · Evaluation B: Bubbles are confirmed on the bonding surface (interface between the cured resin films).

[0163] The results are shown in Table 1.

[0164]

Table 1

[0165] From Table 1, the following can be understood. When baking twice after temporary bonding as in Examples 1 to 9, it can be seen that the mixing of air bubbles in the resin is suppressed, the conductivity is good, and the bonding property of the two chips is good. In particular, as in Example 2, even when one of the thermosetting resin films is in a cured state, both the shear force and the conductivity are good. Therefore, if at least one of the thermosetting resin films is in an uncured state, it can be seen that the shear force can be made good and the mixing of air bubbles in the resin can be suppressed. On the other hand, when baking only once after temporary bonding as in Comparative Examples 1 to 8, it can be seen that the mixing of air bubbles in the resin (bonding surface) cannot be suppressed. Also, as in Comparative Example 9, when the complex viscosity at 80 °C is 1 × 10 4 Pa·s or more, it can be seen that even when baking twice after temporary bonding, the mixing of air bubbles in the resin cannot be suppressed. Also, as in Comparative Example 10, when both thermosetting resin films are cured, it can be seen that the shear force is small and the bonding property of the two chips is poor. Also, as in Comparative Example 11, when the thermosetting resin film is attached to only one of the chips, it can be seen that the shear force is small and the bonding property of the two chips is poor. [Explanation of Symbols]

[0166] (x) Thermosetting resin film (x)' Cured resin film 1a, 1b, 1c Composite Sheet 10 Base material 10a One side of the substrate 11 Buffer layer 13 Intermediate delamination layer 20 Semiconductor wafers (α), (β) Circuit formation surface of semiconductor wafer 21 Protruding electrode 50 semiconductor chips 60 Semiconductor chips with thermosetting resin film

Claims

1. A method for manufacturing a semiconductor device, comprising obtaining a joint in which a first member having a circuit forming surface (α) and a second member having a circuit forming surface (β) are electrically connected via a protruding electrode provided on at least one of the circuit forming surface (α) and the circuit forming surface (β), The circuit-forming surface (α) of the first member and the circuit-forming surface (β) of the second member each have a complex viscosity of 1 × 10 at 80°C. ４ Step (S1) of preparing a first and second workpiece to be joined, wherein a thermosetting resin film (x) having a hardness of less than Pa·s is attached to the workpiece, and at least one of the thermosetting resin films (x) is in an uncured state, Step (S2) is to bring the surface of the first workpiece to be joined on the circuit-forming surface (α) side and the surface of the second workpiece to be joined on the circuit-forming surface (β) side into opposing contact and bond them together to obtain a temporary joint, The temporary joint is formed when the complex viscosity of the thermosetting resin film (x) is 1 × 10 ４ The process (S3) involves heating the thermosetting resin film (x) to a temperature below Pa·s, then further increasing the temperature to heat-cur it and obtain the bonded body, A method for manufacturing a semiconductor device, including the method described above.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the thermosetting resin film (x) used in the above step (S1) is a composite sheet comprising a support sheet.

3. A method for manufacturing a semiconductor device according to claim 1 or 2, wherein a fluxing agent is added to the thermosetting resin film (x).

4. The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the thermosetting resin film (x) contains polyvinyl acetal resin.

5. A thermosetting resin film used in the manufacturing method described in claim 1 or 2.

6. A composite sheet comprising a thermosetting resin film and a support sheet, used in the manufacturing method described in claim 1 or 2.

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