Semiconductor film adhesives, methods for manufacturing semiconductor film adhesives, adhesive tapes, methods for manufacturing semiconductor devices, and semiconductor devices.

Abstract

A semiconductor film adhesive (1) has a first adhesive region (2) and a second adhesive region (3) along the thickness direction. The first adhesive region (2) has photocurability and thermosetting properties, while the second adhesive region (3) has thermosetting properties but no photocurability.

Description

Technical Field

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

[0002] Previously, wire bonding, using fine metal wires such as gold wires, was widely used to connect semiconductor wafers to substrates. On the other hand, in order to meet the requirements of high functionality, high integration, and high speed of semiconductor devices, flip chip bonding (FC bonding) is expanding, which involves forming conductive bumps called bumps on the semiconductor wafer or substrate to directly connect the semiconductor wafer and the substrate.

[0003] For example, regarding the connection between semiconductor wafers and substrates, the COB (Chip On Board) type connection widely used in BGA (Ball Grid Array) and CSP (Chip Size Package) is equivalent to the FC (Front-Chip) connection. Furthermore, the FC connection is also widely used in the COC (Chip On Chip) type connection, which connects semiconductor wafers by forming interconnects (e.g., bumps and wiring) on ​​the semiconductor wafer.

[0004] Furthermore, in the context of strong demands for further miniaturization, thinning, and high-functionality packaging, the aforementioned connection methods are increasingly being used to stack chips and create multi-level chip stacking packages, POP (Package On Package), and TSV (Through-Silicon Via). Because this stacking / multi-level technology arranges semiconductor chips in three dimensions, it can reduce package size compared to two-dimensional methods. Moreover, it is effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, thus attracting significant attention as a new era of semiconductor wiring technology.

[0005] Furthermore, from the perspective of improving productivity, COW (Chip on Wafer) technology, which involves bonding (connecting) semiconductor wafers onto a semiconductor wafer and then monolithically fabricating semiconductor packages, has also attracted considerable attention. In addition, from the same perspective, gang bonding, a method that involves aligning and temporarily bonding multiple semiconductor wafers on a semiconductor wafer or board map, followed by a comprehensive final bonding of these multiple semiconductor wafers to ensure connection, has also garnered significant attention.

[0006] When connecting components such as semiconductor wafers as described above are joined together, thermosetting film adhesives are used (for example, see Patent Document 1). Although the film adhesive is cured by heating during joining (pressing), if the film adhesive is cured before the connecting parts of the connected components come into contact with each other by pressing, the cured product of the adhesive will interfere with the state between the connecting parts and cause poor connection. Therefore, the adhesive needs to exhibit appropriate fluidity during joining.

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2008-294382

[0008] In recent years, due to the increasing functionality and integration of packaging, the gaps between layers and the spacing between wirings have become narrower. As a result, the adhesive flowing during connection has become more prone to overflowing from the ends of the connecting components (e.g., semiconductor wafers), easily forming overflow portions known as fillets. Since these fillets can cause damage to the connecting components, there is a need to develop methods to ensure conductivity (connection reliability) between connecting components and to reduce the amount of fillets generated. Summary of the Invention

[0009] Therefore, the main objective of this disclosure is to provide a semiconductor film adhesive that can ensure sufficient connection reliability and suppress the amount of rounded corners generated.

[0010] This disclosure provides the following [1]~

[18] .

[0011] [1] A semiconductor film adhesive has a first adhesive region and a second adhesive region along its thickness direction. The aforementioned first adhesive region has both photocurable and thermosetting properties. The aforementioned second adhesive region is thermosetting rather than photocurable.

[0012] [2] As described in [1], a semiconductor film adhesive, wherein The aforementioned first adhesive region contains a photopolymerizable compound, a photopolymerization initiator, a thermosetting resin, and a thermosetting agent.

[0013] [3] As described in [2], a semiconductor film adhesive, wherein The aforementioned photopolymerizable compounds are free radical polymerizable compounds, and the aforementioned photopolymerization initiators are photofree radical polymerization initiators.

[0014] [4] As described in [3], a semiconductor film adhesive, wherein The aforementioned free radical polymerizable compounds include (meth)acrylic acid compounds.

[0015] [5] The semiconductor film adhesive as described in any one of [2] to [4], wherein The aforementioned thermosetting resins include epoxy resins.

[0016] [6] As described in [5], a semiconductor film adhesive, wherein The aforementioned thermosetting agents include imidazole-based curing agents.

[0017] [7] As described in [6], a semiconductor film adhesive, wherein The aforementioned imidazole-based curing agents have a tri-ring structure.

[0018] [8] The semiconductor film adhesive as described in any one of [2] to [7], wherein The ratio of the content of the aforementioned thermosetting resin to the content of the aforementioned photopolymerizable compound in the first adhesive region is 3 to 11 by mass.

[0019] [9] A semiconductor film adhesive as described in any one of [1] to [8], wherein The aforementioned second adhesive region contains a thermosetting resin, a thermosetting agent, and a flux compound.

[0020]

[10] As described in [9], a semiconductor film adhesive, wherein The aforementioned fluxing compound has two or more carboxyl groups.

[0021]

[11] The semiconductor film adhesive as described in any one of [1] to

[10] , wherein The thickness of the second adhesive region is 0.5 to 2 times the thickness of the first adhesive region.

[0022]

[12] A semiconductor film adhesive as described in any one of [1] to

[11] is used to bond a semiconductor wafer and a substrate and to seal the gap between the semiconductor wafer and the substrate.

[0023]

[13] A method for manufacturing a semiconductor film adhesive according to any one of [1] to

[12] , comprising: The step of placing one of a first adhesive layer having photocurability and thermosetting properties, and a second adhesive layer having thermosetting properties but not photocurability, on top of the other.

[0024]

[14] An adhesive tape comprising: The semiconductor film adhesive described in any one of [1] to

[12] ; and The back-abrasion tape is disposed on the side opposite to the side of the first adhesive region when viewed from the second adhesive region on the aforementioned semiconductor film adhesive.

[0025]

[15] A method for manufacturing a semiconductor device, comprising: The photoirradiation step of irradiating light onto the first adhesive region of the semiconductor film adhesive described in any one of [1] to

[12] ; and The step of heating and bonding a semiconductor wafer and a substrate in a state where their connection points are facing each other after being irradiated with light using a semiconductor film adhesive. The aforementioned light irradiation step is performed while the aforementioned semiconductor film adhesive is attached from the first adhesive region side to the bonding surface of the aforementioned semiconductor wafer or its precursor, or the bonding surface of the aforementioned substrate or its precursor.

[0026]

[16] The method for manufacturing a semiconductor device as described in

[15] further includes: The step of preparing an adhesive tape includes the aforementioned semiconductor film adhesive and a backing adhesive tape disposed on the semiconductor film adhesive and on the side opposite to the aforementioned first adhesive region when viewed from the aforementioned second adhesive region; The lamination step of attaching the aforementioned adhesive tape from the semiconductor film adhesive side to the bonding surface of the semiconductor wafer precursor or the substrate precursor; and The back grinding step involves grinding the aforementioned precursor, to which the aforementioned adhesive tape is attached, from the side opposite to the aforementioned adhesive tape.

[0027]

[17] The method for manufacturing a semiconductor device as described in

[17] , wherein The aforementioned light irradiation step is performed after the aforementioned back grinding step, and after the aforementioned back grinding tape is removed.

[0028]

[18] A semiconductor device includes: a semiconductor wafer having a first connection portion; a substrate having a second connection portion electrically connected to the first connection portion; and a sealing portion that joins the semiconductor wafer and the substrate and fills the gap between the semiconductor wafer and the substrate. The aforementioned sealing portion is a cured product of the semiconductor film adhesive described in any one of [1] to

[12] . [Invention Effects]

[0029] According to this disclosure, a semiconductor film adhesive can be provided that can ensure sufficient connection reliability and suppress the amount of rounded corners generated. Simple Explanation of the Diagram

[0030] Figure 1 is a schematic cross-sectional view showing one embodiment of the semiconductor film adhesive disclosed herein. Figure 2 is a schematic cross-sectional view showing one embodiment of the semiconductor device disclosed herein. Figure 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device disclosed herein. Figure 4 is a schematic cross-sectional view illustrating one embodiment of the manufacturing method of the semiconductor device disclosed herein. Figure 5 is a schematic cross-sectional view illustrating one embodiment of the manufacturing method of the semiconductor device disclosed herein. Figure 6 is a schematic cross-sectional view illustrating one embodiment of the manufacturing method of the semiconductor device disclosed herein. Figure 7 is a schematic cross-sectional view illustrating one embodiment of the manufacturing method of the semiconductor device disclosed herein. Figure 8 is a schematic cross-sectional view illustrating one embodiment of the manufacturing method of the semiconductor device disclosed herein. Figure 9 is a schematic cross-sectional view showing one embodiment of the manufacturing method of the semiconductor device disclosed herein. Implementation

[0031] In this specification, "(meth)acrylic acid" refers to at least one of acrylic acid and its corresponding methacrylic acid. The same applies to other similar expressions such as "(meth)acrylamide" and "(meth)acrylate". Furthermore, the numerical range indicated by "~" represents the range encompassed by the values ​​before and after "~" as the minimum and maximum values, respectively. Also, the upper or lower limit of the numerical range described in this specification can be replaced by the values ​​shown in the examples. Furthermore, the individually stated upper and lower limits can be arbitrarily combined. Furthermore, unless otherwise specified, the materials exemplified below can be used individually or in combination of two or more. When there are multiple substances equivalent to each component in the composition, unless otherwise specified, the content of each component in the composition represents the total amount of the multiple substances present in the composition.

[0032] The embodiments disclosed herein will be described in detail below with reference to the accompanying drawings. Furthermore, in the drawings, identical or equivalent parts are labeled with the same symbols, and redundant explanations are omitted. Also, regarding positional relationships such as top, bottom, left, and right, unless otherwise specified, they are assumed to be based on the positional relationships shown in the drawings. In addition, the dimensional ratios in the drawings are not limited to those shown.

[0033] <Film Adhesives for Semiconductors> One embodiment of a semiconductor film adhesive (hereinafter referred to as "film adhesive") is an adhesive used for connecting (bonding) and sealing of connecting components such as semiconductor wafers, for example, for bonding a semiconductor wafer to a substrate and sealing the gap between the semiconductor wafer and the substrate.

[0034] Figure 1 is a schematic cross-sectional view showing one embodiment of the film-like adhesive. The film-like adhesive 1 shown in the figure has, along its thickness direction (vertical direction in Figure 1), a first adhesive region 2, which is photocurable and thermosetting; and a second adhesive region 3, which is thermosetting but not photocurable. Hereinafter, the adhesive constituting the first adhesive region 2 will be referred to as the first adhesive, and the adhesive constituting the second adhesive region 3 will be referred to as the second adhesive.

[0035] The first adhesive region 2 and the second adhesive region 3 have a predetermined thickness, for example, as shown in FIG1, extending along the main surface direction of the film adhesive 1 (the left-right direction of FIG1). The boundary between the first adhesive region 2 and the second adhesive region 3 is not necessarily clear and is sometimes difficult to distinguish visually. In addition, in FIG1, although the first adhesive region 2 and the second adhesive region 3 are adjacent to each other, there may be a region between the first adhesive region 2 and the second adhesive region 3 that is different from the first adhesive region 2 and the second adhesive region 3 (for example, a region containing a mixture of the first adhesive and the second adhesive).

[0036] Regarding the film adhesive 1, since the first adhesive region 2 is photocurable, it can easily achieve localized low flowability upon light irradiation. Specifically, for example, by applying the film adhesive 1 to one of the two connecting members (or its precursor) and then irradiating it with light, the flowability of the first adhesive region 2 can be reduced. Therefore, the film adhesive 1 can suppress excessive flow of the adhesive when connecting the connecting members and can suppress the amount of fillet formation. On the other hand, since the second adhesive region 3 of the film adhesive 1 is not photocurable, by applying the film adhesive 1 to one of the connecting members from the side of the first adhesive region 2 (the side opposite to the side of the second adhesive region 3) and then irradiating it with light, the flowability of the other connecting member side (i.e., the side of the second adhesive region 3) can be maintained after light irradiation. Therefore, the film adhesive 1 can also ensure sufficient connection reliability.

[0037] Furthermore, the first adhesive region 2 is designed to be both photocurable and thermosetting, maintaining appropriate fluidity after photocuring and further curing by heating (thermosetting). Therefore, even when the adhesive covers the surface of the joint when the film adhesive 1 is applied, the adhesive is removed during the joining process, making it difficult for cured adhesive residue to remain between the joints after joining. This design of the first adhesive is one of the reasons why sufficient joining reliability is achieved through the film adhesive 1. The overall fluidity of the adhesive during joining can be changed not only by adjusting the thickness, composition, and light irradiation of the first adhesive region 2, but also by adjusting the thickness and composition of the second adhesive region 3. This, for example, ensures good sealing performance (adhesive filling) by reducing the amount of voids generated.

[0038] Furthermore, when using only adhesives with low fluidity, gaps or other problems may occur because the adhesive is not sufficiently embedded between the joints of the connecting members. However, in the above method, since the film adhesive 1 is applied to the connecting members before reducing the fluidity of the first adhesive region 2 (i.e., before light irradiation), the occurrence of such problems can also be suppressed by the film adhesive 1.

[0039] However, from the viewpoint of ensuring sufficient connection reliability (e.g., insulation reliability), metal bonding is typically used when connecting connecting components to each other. The main metals used in the connecting parts (e.g., bumps and wiring) of the connecting components include solder, tin, gold, silver, copper, nickel, etc., and conductive materials containing several of these are also used. On the surface of the connecting parts, impurities such as oxide films formed by the oxidation of the aforementioned metals and oxides adhere, resulting in impurities. If such impurities remain, the connection reliability between the connecting components decreases, leading to the loss of the advantages of the aforementioned connection method. Therefore, to remove the aforementioned oxide films and impurities, a flux compound can be included in the film adhesive 1. As described above, since the film adhesive 1 is attached to one of the connecting components from the first adhesive region 2 side and flows onto the connecting surface of the other connecting component from the second adhesive region 3 side, it is preferable that the second adhesive region 3 contains a flux compound.

[0040] (First adhesive area) The first adhesive region, for example, contains a photopolymerizable compound, a photopolymerization initiator, a thermosetting resin, and a thermosetting agent. Here, "photopolymerizable compound" refers to a compound that polymerizes with active species (free radicals, cations, or anions) generated by a photopolymerization initiator under the influence of light (e.g., ultraviolet light), and "thermosetting resin" refers to a compound that is cured by reacting with a thermosetting agent under heat.

[0041] [Photopolymerizable compounds] Photopolymerizable compounds can be free radical polymers, cationic polymers, or anionic polymers. The polymerizability of a photopolymerizable compound can be selected based on the relationship between the curing properties of the thermosetting resin and the thermosetting agent, ensuring that the reaction does not hinder the reaction. For example, if the thermosetting resin exhibits cationic or anionic curing properties, a free radical polymerizable compound is preferable as the photopolymerizable compound.

[0042] From the perspective of reaction rate, free radical polymerizable compounds are preferred for photopolymerization. In this case, a photofree radical polymerization initiator is used as the photopolymerization initiator.

[0043] Examples of free radical polymerizable compounds include (meth)acrylic acid compounds and vinyl compounds. From the viewpoint of excellent durability, electrical insulation, and heat resistance, (meth)acrylic acid compounds are preferred as free radical polymerizable compounds. Any (meth)acrylic acid compound can be a compound having one or more (meth)acrylic acid groups within its molecule. Examples of (meth)acrylic acid compounds that can be used include bisphenol A type, bisphenol F type, naphthyl type, phenolic varnish type, cresolic varnish type, phenolic alkyl type, biphenyl type, triphenylmethane type, dicyclopentadiene type, fumonisin type, and (meth)acrylic acid compounds containing adamantane or isocyanuric acid backbones; various polyfunctional (meth)acrylic acid compounds (excluding (meth)acrylic acid compounds containing the aforementioned backbones), etc. Examples of polyfunctional (meth)acrylate compounds include neopentyl terephthalol tri(meth)acrylate, dinepentyl terephthalol poly(meth)acrylate (dinepentyl terephthalol penta(meth)acrylate, dinepentyl terephthalol hexa(meth)acrylate, etc.), and trimethylolpropane di(meth)acrylate. Among these, polyfunctional (meth)acrylate compounds are preferred, and dinepentyl terephthalol poly(meth)acrylate is more preferred. The number of functional groups (the number of (meth)acrylic acid groups) in the polyfunctional (meth)acrylate compound is preferably 2 to 8, more preferably 3 to 7, and even more preferably 4 to 6.

[0044] The molecular weight of photopolymerizable compounds is, for example, 400-2000. A molecular weight less than 2000 is preferred, and below 1000 is even better. The smaller the molecular weight of the photopolymerizable compound, the easier it is to react, and the higher the curing rate.

[0045] Photopolymerizable compounds can be used alone or in combination of two or more.

[0046] From the viewpoint of further reducing the amount of fillet formation, the content of the photopolymerizable compound in the first adhesive region 2 is preferably 1% by mass or more, more preferably 3% by mass or more, and more preferably 5% by mass or more, based on the total amount of the first adhesive. From the viewpoint of improving sealing performance and suppressing void formation, the content of the photopolymerizable compound is preferably 10% by mass or less, more preferably 7% by mass or less, and more preferably 5% by mass or less, based on the total amount of the first adhesive. From these viewpoints, the content of the photopolymerizable compound is preferably 1 to 10% by mass, more preferably 3 to 7% by mass, and more preferably 3 to 5% by mass, based on the total amount of the first adhesive.

[0047] [Photopolymerization initiator] Photopolymerization initiators can be photoradical polymerization initiators, cationic polymerization initiators, or anionic polymerization initiators. The choice of photopolymerization initiator depends on the type of photopolymerizable compound; for the same reasons as with photopolymerizable compounds, using photoradical polymerization initiators is preferable.

[0048] Photoradical polymerization initiators are, for example, compounds that decompose and generate free radicals upon irradiation with light (e.g., ultraviolet light), wherein the light has a wavelength in the range of 150-750 nm, preferably in the range of 254-405 nm, and even more preferably in the range of 365 nm. As photoradical polymerization initiators, a single compound can be used alone, or a combination of multiple compounds can be used.

[0049] Examples of photoradical polymerization initiators include those having structures such as oxime ester, diimidazole, acridine, α-aminoalkylphenyl ketone, aminobenzophenone, N-phenylglycine, phosphine oxide, benzyl dimethyl ketal, α-hydroxyalkylphenyl ketone, and α-hydroxyacetophenone. Among these, from the viewpoint of reactivity and further reducing the amount of rounded corners, it is preferable to use a compound having at least one structure selected from the group consisting of phosphine oxide, α-hydroxyalkylphenyl ketone, and α-hydroxyacetophenone; more preferably, a compound having at least one structure selected from the group consisting of phosphine oxide and α-hydroxyacetophenone; and even more preferably, a compound having phosphine oxide.

[0050] Specific examples of compounds having a phosphine oxide structure include bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

[0051] Specific examples of compounds having an α-hydroxyalkylphenyl ketone structure include 1-hydroxycyclohexylphenyl ketone.

[0052] Specific examples of compounds having the α-hydroxyacetophenone structure include 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionic acid)benzyl)phenyl)-2-methylpropane-1-one, etc.

[0053] In the above, it is preferable to use at least one compound selected from the group consisting of 1-hydroxycyclohexylphenyl ketone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionic acid)benzyl)phenyl)-2-methylpropane-1-one, more preferably to use at least one compound selected from the group consisting of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionic acid)benzyl)phenyl)-2-methylpropane-1-one, and even more preferably to use phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0054] From the perspective of suppressing volatilization caused by heat during film formation and adhesion, it is preferable for the molecular weight of the photoradical polymerization initiator to be 400 or higher (e.g., 300-600).

[0055] From the viewpoint of facilitating thorough curing, the content of the photoradical polymerization initiator in the first adhesive region 2 is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and more than 1 part by mass relative to 100 parts by mass of the photopolymerizable compound. From the viewpoint of suppressing the shortening of molecular chains and the residue of unreacted groups due to rapid curing reaction, the content of the photoradical polymerization initiator is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and more preferably 1.5 parts by mass or less, relative to 100 parts by mass of the photopolymerizable compound. From these viewpoints, the content of the photoradical polymerization initiator is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, and more preferably 0.5 to 1.5 parts by mass relative to 100 parts by mass of the photopolymerizable compound.

[0056] [Thermosetting resins] Examples of thermosetting resins include epoxy resins, phenolic resins (except where they are contained as curing agents), and acrylic resins. Among these, epoxy resins are preferred. In thermosetting resins, the epoxy resin content, based on the total amount of thermosetting resin, is preferably 80% by mass or more, and more preferably 90% by mass or more. The epoxy resin content, based on the total amount of thermosetting resin, can be 100% by mass.

[0057] Epoxy resin is a compound having two or more epoxy groups within its molecule. Examples of epoxy resins that can be used include bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, phenolic varnish type epoxy resin, cresolic varnish type epoxy resin, phenolic alkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, pyrrolidone type epoxy resin, dicyclopentadiene type epoxy resin, and various multifunctional epoxy resins. These can be used alone or as a mixture of two or more. Among these, the use of pyrrolidone type epoxy resin (an epoxy resin containing a triphenolic methane backbone) tends to further reduce the amount of fillet radius produced.

[0058] Regarding epoxy resins, from the viewpoint of suppressing the decomposition and generation of volatile components during high-temperature bonding, it is preferable to use epoxy resins with a thermal weight loss rate of less than 5% at 250°C when the bonding temperature is 250°C, and it is preferable to use epoxy resins with a thermal weight loss rate of less than 5% at 300°C when the bonding temperature is 300°C.

[0059] From the viewpoint of easily suppressing the formation of cracks and fissures on the film surface, epoxy resins that are liquid at 25°C (hereinafter referred to as "liquid epoxy resins") can be used as epoxy resins. "Liquid at 25°C" means that the viscosity at 25°C, measured using an E-type viscometer, is 400 Pa·s or less. Examples of liquid epoxy resins include bisphenol A glycidyl ether, bisphenol AD ​​glycidyl ether, bisphenol S glycidyl ether, bisphenol F glycidyl ether, hydrogenated bisphenol A glycidyl ether, ethylene oxide adduct bisphenol A glycidyl ether, propylene oxide adduct bisphenol A glycidyl ether, glycidyl ether of naphthalene resin, and trifunctional or tetrafunctional glycidylamines.

[0060] From the perspective of easily suppressing the formation of cracks and fissures on the film surface, the content of liquid epoxy resin in the thermosetting resin is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, based on the total amount of thermosetting resin. From the perspective of easily suppressing excessive increase in film viscosity and edge fusion, the content of liquid epoxy resin is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, based on the total amount of thermosetting resin.

[0061] The reactive functional group equivalent of thermosetting resins (e.g., the epoxy equivalent of epoxy resins) can be 100~3000 g / eq, 100~2000 g / eq, or 100~1500 g / eq. If the reactive functional group equivalent is within the above range, the balance between reactivity and flowability during heating can easily become good.

[0062] From the viewpoint of easily suppressing the formation of rounded corners, the content of thermosetting resin in the first adhesive region 2 is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more, based on the total amount of the first adhesive. From the viewpoint of easily obtaining good sealing performance and easily suppressing the formation of voids, the content of thermosetting resin is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less, based on the total amount of the first adhesive.

[0063] The content of the aforementioned thermosetting resin can also be set based on its relationship with the content of the photopolymerizable compound. If the ratio of the content of the thermosetting resin to the content of the photopolymerizable compound in the first adhesive region 2 is 3 to 11 by mass, it tends to easily obtain high bonding reliability and further reduce the amount of fillet formation. From the viewpoint of further reducing the amount of fillet formation, the above ratio can be 5 or more, 7 or more, or 9 or more. In addition to the above effects, from the viewpoint of easily obtaining good sealing performance and easily suppressing the formation of voids, it can be 10 or less.

[0064] [Thermosetting agent] As a thermosetting agent, well-known curing agents known as curing agents for thermosetting resins can be used. Thermosetting agents also include materials commonly known as curing accelerators. When epoxy resin is used as the thermosetting resin, phenolic resin-based curing agents, anhydride-based curing agents, amine-based curing agents, imidazole-based curing agents, phosphine-based curing agents, etc., can be used as thermosetting agents. Among these, phenolic resin-based curing agents, anhydride-based curing agents, amine-based curing agents, and imidazole-based curing agents exhibit flux activity that inhibits the formation of an oxide film at the joint; therefore, by using these thermosetting agents, the reliability of the joint can be improved. From the viewpoint of being able to cure rapidly under heating conditions at low temperatures, the use of imidazole-based curing agents is preferable.

[0065] Examples of imidazole-based curing agents include, for example, 2-phenylimidazolium, 2-phenyl-4-methylimidazolium, 1-benzyl-2-methylimidazolium, 1-benzyl-2-phenylimidazolium, 1-cyanoethyl-2-undecylimidazolium, 1-cyano-2-phenylimidazolium, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-tris-triazine, 2,4-diamino-6-[ [2'-Undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanate adduct, 2-phenylimidazolyl isocyanate adduct, 2-phenyl-4,5-dihydroxymethylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, and epoxy resin adducts with imidazoles. Furthermore, latent curing agents that microencapsulate these compounds can also be used. These compounds can be used alone or in combination of two or more. Among these, from the viewpoint of easily obtaining better sealing performance and easily suppressing the formation of voids, compounds having a triazine ring are preferred.

[0066] From the viewpoint of improving curability upon heating, it is preferable that the content of the thermosetting agent in the first adhesive region 2 is 1 part by weight or more relative to 100 parts by weight of the thermosetting resin, more preferably 2 parts by weight or more, and even more preferably 3 parts by weight or more. From the viewpoint of making it more difficult for the first adhesive to intervene between the joints, it is preferable that the content of the thermosetting agent is 10 parts by weight or less relative to 100 parts by weight of the thermosetting resin, more preferably 7 parts by weight or less, and even more preferably 5 parts by weight or less.

[0067] [Other ingredients] Other components besides those mentioned above in the first adhesive region 2 can be, for example, thermoplastic resins, fillers (fillers), etc.

[0068] Thermoplastic resins contribute to improved heat resistance and film-forming properties. Examples of thermoplastic resins include phenoxy resins, polyimide resins, polyamide resins, polycarbodiimide resins, cyanate ester resins, acrylic resins, polyester resins, polyethylene resins, polyether resins, polyetherimide resins, polyvinyl acetal resins, urethane resins, and acrylic rubbers. Among these, phenoxy resins, polyimide resins, acrylic rubbers, cyanate ester resins, and polycarbodiimide resins are preferred from the viewpoint of readily obtaining excellent heat resistance and film-forming properties; phenoxy resins, polyimide resins, and acrylic rubbers are even more preferred. These thermoplastic resins can also be used alone or as mixtures or copolymers of two or more.

[0069] The weight-average molecular weight of the thermoplastic resin is, for example, 10,000 or more, or 20,000 or more, or 30,000 or more. Based on this thermoplastic resin, the heat resistance and film-forming properties of the first adhesive can be further improved. From the viewpoint of easily obtaining improved heat resistance, the weight-average molecular weight of the thermoplastic resin can be 1,000,000 or less, or 500,000 or less. Furthermore, in this specification, the weight-average molecular weight refers to the weight-average molecular weight measured using a high-performance liquid chromatography (HPLC) instrument (manufactured by SHIMADZU CORPORATION, product name: C-R4A) converted to polystyrene. During the measurement, for example, the following conditions can be used. Detector: LV4000 UV Detector (manufactured by Hitachi, Ltd., product name) Pump: L6000 Pump (manufactured by Hitachi, Ltd., product name) Column: Gelpack GL-S300MDT-5 (2 in total) (manufactured by Showa Denko Materials Co., Ltd.) Solution: THF / DMF = 1 / 1 (volume ratio) + LiBr (0.03 mol / L) + H3PO4 (0.06 mol / L) Flow rate: 1 mL / min

[0070] From the viewpoint of excellent adhesion of the film adhesive to the connecting component (e.g., semiconductor wafer), a glass transition temperature (Tg) of 120°C or lower for the thermoplastic resin is preferred, 100°C or lower is more preferred, and 85°C or lower is further preferred. The aforementioned Tg refers to the Tg measured using a DSC (manufactured by PerkinElmer Co., Ltd., product name: DSC-7) under the conditions of a sample volume of 10 mg, a heating rate of 10°C / min, and an air atmosphere.

[0071] From the viewpoint of easily improving the heat resistance and film-forming properties of the first adhesive, the content of thermoplastic resin in region 2 of the first adhesive is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the first adhesive. From the viewpoint of easily suppressing the formation of rounded corners, the content of thermoplastic resin is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the first adhesive.

[0072] The filler is effective in controlling the viscosity of the first adhesive and the physical properties of the cured first adhesive. Specifically, by using the filler, it is possible to suppress voids generated during bonding and reduce the moisture absorption rate of the cured first adhesive. The filler can be an inorganic filler (inorganic particles) or an organic filler (organic particles). Examples of inorganic fillers include insulating inorganic fillers such as glass, silica, alumina, titanium dioxide, mica, and boron nitride. Among these, it is preferable to use at least one selected from the group consisting of silica, alumina, titanium dioxide, and boron nitride, and even more preferable to use at least one selected from the group consisting of silica, alumina, and boron nitride. Examples of organic fillers include resin fillers (resin particles). Examples of resin fillers include polyurethane and polyimide. Depending on the resin filler, flexibility at high temperatures such as 260°C can be imparted. In addition, organic fillers made of thermoplastic resins do not conform to the above-mentioned thermoplastic resins.

[0073] From the perspective of superior insulation reliability, it is preferable for the filler to have insulating properties. It is also preferable that the first adhesive does not contain fillers containing conductive materials such as silver, solder, or carbon black (conductive fillers).

[0074] The physical properties of fillers can be appropriately adjusted through surface treatment. From the viewpoint of improving dispersibility or adhesion, fillers that have undergone surface treatment can be used. Examples of surface treatment agents include glycidyl (epoxy), amine, phenyl, phenylamine, (meth)acrylic, and ethylene compounds.

[0075] The average particle size of the filler is, for example, 0.5 to 1.5 μm. From the viewpoint of preventing biting during flip chip bonding, an average particle size of 1.5 μm or less is preferred, and from the viewpoint of excellent visual discrimination (transparency), 1.0 μm or less is even better. In addition, the average particle size of the filler is the particle size at the point corresponding to 50% of the volume when the cumulative frequency distribution curve based on particle size is obtained with 100% of the total particle volume, and can be measured using a particle size distribution measuring device such as a laser diffraction scattering method.

[0076] From the perspective of suppressing the reduction of exothermic properties and easily suppressing the formation of voids and the increase of moisture absorption, the filler content in the first adhesive region 2 is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more, based on the total amount of the first adhesive. From the perspective of suppressing filler trapping into the joint, the filler content is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less, based on the total amount of the first adhesive.

[0077] When the filler includes both inorganic and organic fillers, the content of inorganic filler in the first adhesive region 2 is based on the total amount of filler in the first adhesive region 2, and can be 60% or more by mass, 70% or more by mass, or 80% or more by mass, or 98% or less by mass, 95% or less by mass, or 90% or less by mass, or 60 to 98% by mass, 70 to 95% by mass, or 80 to 90% by mass.

[0078] In the first adhesive region 2, additives such as antioxidants, silane coupling agents, titanium coupling agents, leveling agents, and ion scavengers may be further included. These can be used individually or in combination of two or more. The content of these additives can be appropriately adjusted to exhibit the effects of each additive. Although the first adhesive region 2 may contain flux compounds (described later), the content of the flux compounds is preferably less than 0.5% by mass, more preferably less than 0.01% by mass, and further preferably 0% by mass, based on the total amount of the second adhesive. Especially when the first adhesive has free radical polymerization properties (free radical curing properties), since the curing of the first adhesive is easily hindered by the flux compounds, it is preferable that the first adhesive does not contain flux compounds.

[0079] The thickness of the first adhesive region 2 (the length in the thickness direction of the film-like adhesive 1) can be appropriately set according to the relationship with the height of the connection part in the connection member to which the film-like adhesive 1 is attached before light irradiation. When the height of the above connection part is set as y1 and the thickness of the first adhesive region 2 is set as x1, from the viewpoint that it is difficult for the cured product of the first adhesive to intervene between the connection parts and the connection reliability can be further improved, the relationship between x1 and y1 preferably satisfies x1 < y1, and more preferably satisfies 1.0x1 < y1 ≤ 1.5x1. Specifically, the thickness of the first adhesive region 2 can be 1 to 50 μm, and can also be 3 to 50 μm, 4 to 30 μm or 5 to 20 μm.

[0080] (The second adhesive region) The second adhesive region 3 contains, for example, a thermosetting resin, a thermosetting agent, and a flux compound.

[0081] As the thermosetting resin and the thermosetting agent, the same ones as those exemplified as the thermosetting resin and the thermosetting agent contained in the first adhesive region 2 can be used. The preferred examples of the thermosetting resin and the thermosetting agent are also the same as those in the first adhesive region 2. The thermosetting resin and the thermosetting agent in the first adhesive region 2 and the thermosetting resin and the thermosetting agent in the second adhesive region 3 can be the same or different.

[0082] From the viewpoint of easily suppressing the generation of rounded corners, the content of the thermosetting resin in the second adhesive region 3 is preferably 25% by mass or more, more preferably 30% by mass or more, and further preferably 35% by mass or more based on the total amount of the second adhesive. From the viewpoint of easily obtaining good sealing performance and adhesiveness, the content of the thermosetting resin is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less based on the total amount of the second adhesive.

[0083] From the viewpoint of improving the curability during heating, the content of the thermosetting agent in the second adhesive region 3 is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 3 parts by mass or more relative to 100 parts by mass of the thermosetting resin. From the viewpoint of making it more difficult for the second adhesive to intervene between the connection parts, the content of the thermosetting agent is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and further preferably 5 parts by mass or less relative to 100 parts by mass of the thermosetting resin. In addition, the above thermosetting resin is the thermosetting resin in the second adhesive region 3.

[0084] [Flux compound] Flux compounds are compounds with fluxing activity. As a flux compound, there are no particular restrictions as long as it reduces and removes the oxide film on the surface of solder or similar materials, thereby facilitating metal bonding; known flux compounds can be used. One flux compound can be used alone or in combination of two or more.

[0085] From the viewpoint of obtaining sufficient flux activity and superior bonding reliability, flux compounds with carboxyl groups are preferred, those with two or more carboxyl groups are even better, and those with two carboxyl groups are further preferred. Compared to compounds with one carboxyl group (monocarboxylic acid), compounds with two or more carboxyl groups are less prone to volatilization due to the high temperatures during bonding. Therefore, based on this compound, the formation of voids can be further suppressed. Furthermore, when comparing compounds with two carboxyl groups with compounds with three or more carboxyl groups, compounds with two carboxyl groups show superior performance in suppressing the viscosity increase of the film adhesive 1 during storage / bonding operations.

[0086] As a fluxing compound having a carboxyl group, it is preferable to use a compound having a group represented by the following formula (1). [Chemistry 1]

[0087] In formula (1), R1 represents a hydrogen atom or an electron-donating group.

[0088] From the viewpoints of superior reflow resistance and better connection reliability, it is preferable that R1 is an electron-donating group. In this embodiment, the second adhesive contains epoxy resin, and it is even more preferable that it contains a compound in which R1 is an electron-donating group among the compounds having the group represented by formula (1). In this case, even in flip-chip interconnection, it is easier to fabricate semiconductor devices with superior reflow resistance and connection reliability.

[0089] Examples of electron-donating groups include alkyl, hydroxy, amino, alkoxy, and alkylamino groups. Groups that are less likely to react with other components (e.g., epoxy resins) are preferred as electron-donating groups; specifically, alkyl, hydroxy, or alkoxy groups are preferred, with alkyl groups being even more preferred.

[0090] Alkyl groups can be straight-chain or branched, with straight-chain being preferred. Alkyl groups with 1 to 10 carbon atoms are preferred, and those with 1 to 5 carbon atoms are even more preferred. The more carbon atoms an alkyl group has, the greater its electron-donating ability and steric hindrance tends to be. Alkyl groups with the above-mentioned number of carbon atoms exhibit an excellent balance between electron-donating ability and steric hindrance.

[0091] As a flux compound having two carboxyl groups, the compound represented by the following formula (2) can be used more preferably. According to the compound represented by the following formula (2), the reflow resistance and connection reliability of semiconductor devices can be further improved.

[0092] [Chemistry 2]

[0093] In equation (2), R1 has the same meaning as in equation (1). R2 represents a hydrogen atom or an electron-donating group, and n represents an integer greater than or equal to 0 or 1.

[0094] The electron-donating property represented by R2 is the same as that of the electron-donating group described above as R1. R2 can be the same as or different from R1. There can be multiple R2s that can be the same as or different from each other.

[0095] In Equation (2), n is preferably 1 or more. If n is 1 or more, compared with the case where n is 0, the flux compound is less likely to volatilize even at high temperatures during connection, which can further suppress the formation of voids. Also, in Equation (2), n is preferably 15 or less, 11 or less is even better, and it can also be 6 or less or 4 or less. If n is 15 or less, even better connection reliability can be obtained.

[0096] Specific examples of flux compounds as described above include dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid, as well as compounds in which an electron-donating group is substituted at the second position of the dicarboxylic acid (e.g., 2-methylglutaric acid).

[0097] The flux compound preferably has a melting point below 150°C, more preferably below 140°C, and further preferably below 130°C. This flux compound readily exhibits its fluxing activity before the curing reaction between the epoxy resin and the curing agent. Therefore, by using this flux compound, semiconductor devices with superior connection reliability can be obtained. The flux compound is preferably solid at room temperature (25°C). The flux compound preferably has a melting point above 25°C, and more preferably above 50°C. Furthermore, in this specification, a melting point below 150°C indicates that the upper limit of the melting point is below 150°C, and a melting point above 25°C indicates that the lower limit of the melting point is above 25°C.

[0098] From the viewpoint of achieving better flux performance, the flux compound content in the second adhesive region 3 is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more, based on the total amount of the second adhesive. From the viewpoint of reducing wafer warpage during semiconductor device fabrication, the flux compound content is preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 2% by mass or less, based on the total amount of the second adhesive.

[0099] Similar to the first adhesive region 2, the second adhesive region 3 may further include fillers, thermoplastic resins, etc. These can use the same components as those exemplified as fillers and thermoplastic resins that can be contained in the first adhesive region 2. These preferred examples are also the same as those for the first adhesive region 2. The fillers in the first adhesive region 2 and the fillers in the second adhesive region 3 may be the same or different. The same applies to the thermoplastic resin.

[0100] From the viewpoint of easily improving the heat resistance and film-forming properties of the second adhesive, the content of thermoplastic resin in region 3 of the second adhesive is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass or more, based on the total amount of the second adhesive. From the viewpoint of easily suppressing the formation of rounded corners, the content of thermoplastic resin is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on the total amount of the second adhesive.

[0101] From the perspective of suppressing the reduction of exothermic properties and easily suppressing the formation of voids and the increase of moisture absorption, the filler content in the second adhesive region 3 is preferably 25% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more, based on the total amount of the second adhesive. From the perspective of suppressing filler biting (entrapment) into the joint, the filler content is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less, based on the total amount of the second adhesive.

[0102] The second adhesive region 3 may further include additives exemplified as those that can be included in the first adhesive region 2. The amounts of these additives can be appropriately adjusted to exhibit their respective effects.

[0103] The second adhesive region 3 does not contain a combination of photopolymerizable compounds and photopolymerization initiators. Without using a photopolymerization initiator, the second adhesive region 3 may contain compounds that can be included as photopolymerizable compounds in the first adhesive region 2. However, from the viewpoint of preventing reactions with active species generated during the curing of the first adhesive region 2, it is preferable that the second adhesive region 3 does not contain compounds that polymerize with active species generated by the photopolymerization initiator contained in the first adhesive region. The content of compounds that polymerize with active species generated by the aforementioned photopolymerization initiator is preferably 0.5% by mass or less, more preferably 0.05% by mass or less, and further preferably 0% by mass, based on the total amount of the second adhesive.

[0104] As described above, due to the presence of free radical deactivators and free radical polymerizable compounds in the flux compound, the curing reaction proceeds rapidly upon heating, and the cured product easily integrates into the joints. Therefore, it is preferable that the second adhesive region 3 does not contain free radical polymerizable compounds. The content of free radical polymerizable compounds, based on the total amount of the second adhesive, is preferably 0.5% by mass or less, more preferably 0.05% by mass or less, and further preferably 0% by mass.

[0105] The thickness of the second adhesive region 3 (the length of the film adhesive 1 in the thickness direction) can be 1~50μm, or it can be 3~50μm, 4~30μm or 5~20μm.

[0106] The thickness of the second adhesive region 3 can be 0.5 to 2 times, or 0.5 to 2.5 times or 0.5 to 3 times the thickness of the first adhesive region 2.

[0107] The thickness of the film adhesive 1 (e.g., the sum of the thicknesses of the first adhesive region 2 and the second adhesive region 3) can be appropriately set according to its relationship with the connection portions of the connecting member. When the sum of the heights of the connection portions is set as x, and the total thickness of the film adhesive is set as y, from the viewpoint of adhesion during pressing and adhesive filling, the relationship between x and y is preferably 0.70x ≤ y ≤ 1.3x, and more preferably 0.80x ≤ y ≤ 1.2x. From the viewpoint of preventing the cured product of the first adhesive from easily interfering with the connection portions and further improving connection reliability, it is preferable that y > x. Specifically, the thickness of the film adhesive 1 can be 2~100μm, or 6~100μm, 8~60μm, or 10~40μm.

[0108] The film-like adhesive 1 may have a substrate such as a support film or a protective film on the surface of the first adhesive region 2 (the side opposite to the second adhesive region 3) and / or on the surface of the second adhesive region 3 (the side opposite to the first adhesive region 2). In this disclosure, the laminate having a substrate and the film-like adhesive disposed on the substrate is referred to as an adhesive tape.

[0109] As a substrate, the substrate exemplified as used in the manufacturing method of the film adhesive described later can be used; however, it is preferable that the substrate disposed on the second adhesive region 3 side of the film adhesive 1 is a back-abrasion tape. The back-abrasion tape typically forms an adhesive layer on one main side, but in this case, the back-abrasion tape is disposed on the film adhesive 1 with the adhesive layer side facing the film adhesive 1 (e.g., the adhesive layer is in contact with the film adhesive). The thickness of the substrate 3 (e.g., the thickness of the back-abrasion tape) can be 20~300 μm.

[0110] The adhesive tape can be a laminate of substrate and film adhesive obtained by the manufacturing method of film adhesive described later, that is, by coating a coating liquid onto a substrate to form a film and drying it. Alternatively, it can be a laminate obtained by attaching a substrate (e.g., laminating film adhesive 1 and substrate) to film adhesive 1. When the substrate is a back-abrasion tape, if the coating liquid is applied and dried on the adhesive layer of the back-abrasion tape, problems such as damage to the adhesive layer and component transfer between the adhesive and the bonding agent may occur. Therefore, it is better to obtain the adhesive tape by attaching the back-abrasion tape to film adhesive 1.

[0111] <Manufacturing Method of Film Adhesives for Semiconductors> One embodiment of the manufacturing method of the film adhesive 1 includes the step of placing one of a first adhesive layer having photocurability and thermosetting properties, and a second adhesive layer having thermosetting properties but not photocurability, on top of the other. The first adhesive layer is a layer composed of the aforementioned first adhesive, forming a first adhesive region 2 in the film adhesive 1. The second adhesive layer is a layer composed of the aforementioned second adhesive, forming a second adhesive region 3 in the film adhesive 1.

[0112] In one embodiment, the above steps may include, for example, bonding a first adhesive film having the first adhesive layer to a second adhesive film having the second adhesive layer. In this embodiment, the method for manufacturing the film-like adhesive 1 may further include the steps of preparing the first adhesive film and the second adhesive film.

[0113] The steps for preparing the first adhesive film may include forming a first adhesive layer on a substrate (e.g., a film-like substrate). When forming the first adhesive layer on the substrate, for example, firstly, a photopolymerizable compound, a photopolymerization initiator, a thermosetting resin, a thermosetting agent, and other components (fillers, thermoplastic resins, additives, etc.) as needed are added to an organic solvent, and dissolved or dispersed by stirring, mixing, or kneading to prepare a coating liquid containing the first adhesive. Subsequently, the coating liquid is applied to a substrate that has undergone a demolding treatment using a blade coater, roller coater, or applicator to form a coating film, and then the organic solvent is reduced from the coating film by heating. This allows the first adhesive layer to be formed on the substrate.

[0114] Organic solvents used in the preparation of the coating solution are preferably those capable of uniformly dissolving or dispersing the various components. Examples include dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellulose solvent acetate, butyl cellosolve, dimethyl ether, cyclohexanone, and ethyl acetate. These organic solvents can be used alone or in combination of two or more. The stirring, mixing, and kneading during the preparation of the coating solution can be performed using, for example, a mixer, pounder, three-roll mill, ball mill, bead mill, or homogenizer.

[0115] As a substrate, there are no particular limitations as long as it possesses heat resistance that allows the organic solvent to evaporate under heating conditions. Examples include polypropylene films, polyolefin films such as polymethylpentene films, polyester films such as polyethylene terephthalate films and polyethylene naphthalate films, polyimide films, and polyetherimide films. The substrate is not limited to a single layer composed of such films, but can also be a multilayer film composed of two or more materials. The substrate can be a film with a release treatment applied to its surface.

[0116] The drying conditions for allowing the organic solvent to evaporate from the coating on the substrate are preferably set to conditions that allow the organic solvent to evaporate sufficiently. Specifically, heating at 50–200°C for 0.1–90 minutes is preferable. It is preferable to remove the organic solvent to below 1.5% by mass relative to the total amount of the first adhesive, provided it does not affect the gaps or viscosity adjustment after installation.

[0117] The steps for preparing the second adhesive film may include forming a second adhesive layer on a substrate. Except for the use of thermosetting resins, thermosetting agents, flux compounds, and other components (fillers, thermoplastic resins, additives, etc.) as needed, the second adhesive layer can be formed on the substrate using the same method as that used for forming the first adhesive layer.

[0118] Methods for bonding the first adhesive film and the second adhesive film include, for example, hot pressing, roller lamination, and vacuum lamination. Lamination can be performed, for example, under heating conditions of 30 to 120°C.

[0119] The film-like adhesive 1 can be obtained, for example, by forming one of a first adhesive layer and a second adhesive layer on a substrate, and then forming the other of the first adhesive layer and the second adhesive layer on the obtained first adhesive layer or second adhesive layer. The first adhesive layer and the second adhesive layer can be formed by the above method.

[0120] The film-like adhesive 1 can be obtained, for example, by substantially forming the first adhesive and the second adhesive simultaneously on a substrate. As a method for simultaneously applying the first adhesive and the second adhesive, examples include coating methods such as sequential coating and multilayer coating.

[0121] Semiconductor Devices Next, a semiconductor device manufactured using the semiconductor film adhesive described above will be explained.

[0122] Figure 2 is a schematic cross-sectional view showing one embodiment of a semiconductor device. The semiconductor device 100 shown in Figure 2(a) includes: a semiconductor wafer 20 and a substrate 25 facing each other; wiring (first connection portion and second connection portion) 15 respectively disposed on the facing surfaces of the semiconductor wafer 20 and the substrate 25; connecting bumps 30 connecting the wiring 15 of the semiconductor wafer 20 and the substrate 25 to each other; and a sealing portion 40 composed of a cured adhesive (first adhesive and second adhesive) filling the gap between the semiconductor wafer 20 and the substrate 25. The semiconductor wafer 20 and the substrate 25 are flip-chip connected by the wiring 15 and the connecting bumps 30. The wiring 15 and the connecting bumps 30 are sealed and isolated from the external environment by the cured adhesive. The sealing portion 40 has an upper portion 40a containing the cured first adhesive and a lower portion 40b containing the cured second adhesive.

[0123] The semiconductor device 200 shown in Figure 2(b) includes: a semiconductor wafer 20 and a substrate 25 facing each other; bumps (first connecting portion and second connecting portion) 32 respectively disposed on the facing surfaces of the semiconductor wafer 20 and the substrate 25; and a sealing portion 40 composed of a cured adhesive (first adhesive and second adhesive) filling the gap between the semiconductor wafer 20 and the substrate 25. The semiconductor wafer 20 and the substrate 25 are connected to each other by the facing bumps 32 and are flip-chip connected. The bumps 32 are sealed by the cured adhesive and isolated from the external environment. The sealing portion 40 has an upper portion 40a containing the cured first adhesive and a lower portion 40b containing the cured second adhesive.

[0124] There are no particular limitations on the semiconductor chip 20. Semiconductor chips made of elemental semiconductors such as silicon and germanium, or semiconductor chips made of compound semiconductors such as gallium arsenide and indium phosphide, can be used.

[0125] There are no restrictions on the substrate 25 as long as it is used to mount the semiconductor chip 20. Examples include semiconductor chips, semiconductor wafers, wiring circuit boards, etc.

[0126] The example of a semiconductor wafer that can be used as substrate 25 is the same as the example of semiconductor wafer 20 described above. As substrate 25, the same semiconductor wafer as semiconductor wafer 20 can be used.

[0127] There is no particular limitation on the semiconductor wafer that can be used as the substrate 25; it can be a semiconductor wafer having a plurality of semiconductor wafers exemplified above 20 connected to it.

[0128] There are no particular limitations on the circuit board that can be used as the substrate 25. It can be used on the surface of an insulating substrate with glass epoxy resin, polyimide, polyester, ceramic, epoxy resin, dicis-butene diimide trioxide, etc., to form a circuit board with wiring (wiring pattern) 15 formed by etching away unwanted parts of the metal film, a circuit board with wiring 15 formed on the surface of the insulating substrate by metal plating, etc., or a circuit board with wiring 15 formed by printing conductive material on the surface of the insulating substrate.

[0129] The connecting parts such as wiring 15 and bump 32 contain gold, silver, copper, solder (the main components of which are tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.), nickel, tin, lead, etc., and may contain multiple metals.

[0130] Among the aforementioned metals, from the viewpoint of creating a package with excellent electrical and thermal conductivity at the connection points, gold, silver, and copper are preferred, with silver and copper being even better. From the viewpoint of creating a package with reduced costs, low-cost materials, namely silver, copper, and solder, are preferred, with copper and solder being even better, and solder being even better. If an oxide film forms on the surface of the metal at room temperature, productivity may decrease and costs may increase. Therefore, from the viewpoint of suppressing oxide film formation, gold, silver, copper, and solder are preferred, with gold, silver, and solder being even better, and gold and silver being even better.

[0131] The surfaces of the aforementioned wiring 15 and bump 32 can be plated to form a metal layer with gold, silver, copper, solder (main components such as tin-silver, tin-lead, tin-bismuth, tin-copper, etc.), tin, nickel, etc., as the main components. This metal layer can be composed of a single component or multiple components. Furthermore, the aforementioned metal layer can be a single layer or a stacked structure of multiple metal layers.

[0132] Semiconductor devices can be stacked in multiple layers as shown in semiconductor devices 100 and 200 (packages). In this case, semiconductor devices 100 and 200 can be electrically connected to each other by bumps, wiring, etc., including gold, silver, copper, solder (the main components of which are, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.), tin, nickel, etc.

[0133] As shown in FIG3, a method for stacking multiple semiconductor devices can be exemplified by, for example, TSV (Through-Silicon Via) technology. In the semiconductor device 500 shown in FIG3, wiring 15 formed on the interposer 50 is connected to wiring 15 of the semiconductor wafer 20 via connecting bumps 30, thereby flip-chip bonding of the semiconductor wafer 20 and the interposer 50. The gap between the semiconductor wafer 20 and the interposer 50 is filled with a cured adhesive (first adhesive and second adhesive) to form a sealing portion 40. On the surface of the semiconductor wafer 20 opposite to the interposer 50, the semiconductor wafer 20 is repeatedly stacked via wiring 15, connecting bumps 30, and sealing portion 40. The wiring 15 on the patterned surfaces of the front and back sides of the semiconductor wafer 20 are connected to each other by through electrodes 34 filling the holes penetrating the interior of the semiconductor wafer 20. Furthermore, copper, aluminum, etc., can be used as the material for the through electrodes 34.

[0134] This TSV technology enables signal acquisition even on the back side of a semiconductor wafer that is not normally used. Furthermore, since the through electrode 34 vertically penetrates the semiconductor wafer 20, the distance between opposing semiconductor wafers 20 and between the semiconductor wafer 20 and the interposer 50 can be shortened, and flexible connections can be achieved. The semiconductor film adhesive of this embodiment can be used as a semiconductor film adhesive between opposing semiconductor wafers 20 and between the semiconductor wafer 20 and the interposer 50 in this TSV technology.

[0135] Furthermore, in high-degree-of-freedom bump formation methods such as regional bump wafer technology, semiconductor wafers can be directly mounted onto a motherboard without the need for an interposer. The semiconductor film adhesive of this embodiment can also be applied to situations where semiconductor wafers are directly mounted onto a motherboard. Additionally, the semiconductor film adhesive of this embodiment can also be used to seal the gap (void) between two wiring circuit substrates in the case of stacking two circuit boards.

[0136] <Semiconductor Device Manufacturing Methods> Next, a method for manufacturing a semiconductor device using the semiconductor film adhesive described above will be explained.

[0137] One embodiment of a semiconductor device manufacturing method includes, for example, a light irradiation step of irradiating light onto a first adhesive region 2 of a film adhesive 1; and a step of heating and bonding a semiconductor wafer and a substrate in a state where the semiconductor film adhesive, after light irradiation, is arranged with their connection portions facing each other. The light irradiation step is performed with the film adhesive 1 attached from the first adhesive region 2 side to the connection surface of the semiconductor wafer or its precursor, or the connection surface of the substrate or its precursor. Here, the semiconductor wafer precursor refers to a component that is processed to become a semiconductor wafer. A specific example of a semiconductor wafer precursor is a semiconductor wafer. The same applies to the substrate precursor.

[0138] The method for manufacturing a semiconductor device further includes: a step of preparing an adhesive tape comprising a semiconductor film adhesive and a back-abrasion tape disposed on the semiconductor film adhesive and, when viewed from a second adhesive region, on a side opposite to the first adhesive region; a lamination step of attaching the adhesive tape from the semiconductor film adhesive side to the bonding surface of a precursor or substrate of a semiconductor wafer; and a back-abrasion step of grinding the precursor to which the adhesive tape is attached from the side opposite to the adhesive tape. While light irradiation in the light irradiation step can be performed through the back-abrasion tape, it is preferable to perform it after removing the back-abrasion tape following the back-abrasion step.

[0139] The following are examples of using semiconductor wafers as precursors for semiconductor chips, and the manufacturing method of semiconductor devices will be explained.

[0140] Figures 4 to 9 are schematic cross-sectional views illustrating one embodiment of a semiconductor device manufacturing method. One embodiment of the manufacturing method includes the steps (a) to (e) shown below. Step (a): The step of preparing the laminate 6, which includes: a semiconductor wafer A having a connection portion (first connection portion) 5 on a main surface (connection surface); and a film-like adhesive 1 formed on the surface of the semiconductor wafer A as the side of the first adhesive region 2 (see Figure 4). Step (b): A back-grinding step is performed on the side of the laminate 6 opposite to the side where the film-like adhesive 1 is provided (the side of the semiconductor wafer A opposite to the side where the connector 5 is provided) (see Figure 5). Step (c): Irradiating the laminate 6 after step (b) with light so that the light illuminates the first adhesive region 2 of the film adhesive 1 (see Figure 6). Step (d): The laminate 6 after step (b) is monolithized to obtain a semiconductor wafer 8 with a film-like adhesive and a connecting portion 5 (see Figure 7). Step (e): The step of picking up the semiconductor wafer 8 with the film adhesive from the monolithized film adhesive 1a side (see Figure 8). Step (f): On the main surface of a substrate 9 having a connecting portion ((second connecting portion) 10) on a main surface (connecting surface), a semiconductor wafer 8 with a film adhesive is disposed from the side of the film adhesive 1a and heated, thereby electrically connecting the connecting portion 5 of the semiconductor wafer 8 with the film adhesive and the connecting portion 10 of the substrate 9 (see FIG9). Alternatively, if a semiconductor wafer with pre-adjusted thickness is used, step (b) may be omitted. Furthermore, step (c) can be performed before step (f), either before step (b) or after step (d).

[0141] (Step (a)) Step (a) can be either the step of preparing the pre-made laminate 6 or the step of making the laminate 6. The laminate 6 can be made, for example, by the following method.

[0142] First, an adhesive tape with a substrate 4 disposed on the second adhesive region 3 side of the film adhesive 1 is prepared and placed in a prescribed device (see Figure 4(a)). The substrate 4 is, for example, a back-abrasion adhesive tape. Next, a semiconductor wafer A having a connection portion 5 (wire, bump, etc.) on its main surface is prepared, and the film adhesive 1 is attached to the main surface of the semiconductor wafer A (the surface where the connection portion 5 is disposed, the connection surface). Thereby, a laminate 6 is obtained in which the semiconductor wafer A, the first adhesive region 2, and the second adhesive region 3 are sequentially stacked (see Figure 4(b)).

[0143] The film adhesive 1 can be applied by hot pressing, roll lamination, vacuum lamination, etc. The supply area and thickness of the film adhesive 1 are appropriately set according to the size of the semiconductor wafer and substrate, the height of the connection portion, etc. In addition, in Figure 4, although the thickness of the film adhesive 1 is greater than the height of the connection portion 5 of the semiconductor wafer A, and the connection portion 5 is covered by the film adhesive 1, the thickness of the film adhesive 1 can be less than the height of the connection portion 5.

[0144] (Step (b)) In step (b), for example, a grinding machine G is used to grind the semiconductor wafer A of the stack 6 (see Figures 5(a) and 5(b)). This thins the semiconductor wafer A. The thickness of the ground semiconductor wafer can be, for example, 10 μm to 300 μm. From the viewpoint of miniaturization and thinning of semiconductor devices, a semiconductor wafer thickness of 20 μm to 100 μm is preferred.

[0145] (Step (c)) In step (c), the first adhesive region 2 is photocured by irradiating the laminate 6 with light (see Figures 6(a) and 6(b)). In Figure 6(b), the first adhesive region after photocuring is indicated by the symbol "2'". For example, irradiation can be performed by irradiating light (e.g., ultraviolet light) with a wavelength in the range of 150 to 750 nm from a light source L disposed on the side of the film adhesive 1. As the light source L, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an LED light source, etc. can be used. The amount of light irradiation can be appropriately adjusted; for example, the cumulative light intensity of light with a wavelength of 365 nm can be 100 mJ / cm² or more, 200 mJ / cm² or more, or 300 mJ / cm² or more. The amount of light irradiation, for example, based on the cumulative amount of light with a wavelength of 365 nm, can be less than 1000 mJ / cm², less than 700 mJ / cm², or less than 500 mJ / cm². As shown in Figure 6, when the substrate 4 is transparent, light irradiation can be performed while the substrate 4 is attached to the laminate 6, or after the substrate 4 has been peeled off. When the substrate 4 is a material that can be peeled off by light irradiation, step (c) can also be performed as a step of peeling off the substrate 4.

[0146] (Step (d)) In step (d), for example, firstly, a dicing tape 7 is attached to the semiconductor wafer A side of the stacked body 6 and positioned in a predetermined apparatus (see FIG. 7(a)). If step (c) is performed with the substrate 4 attached to the stacked body 6, the substrate 4 can be peeled off before or after attaching the stacked body 6 to the dicing tape 7. Next, the stacked body 6 is cut using a dicing saw D. Thus, the stacked body 6 is monolithized, resulting in a semiconductor wafer 8 with a film-like adhesive 1a on the semiconductor wafer A' (see FIG. 7(b)). A connecting portion 5 is provided on the surface of the semiconductor wafer A' on the side of the film-like adhesive 1a. The film-like adhesive 1a has a first adhesive region (a region composed of the photocured product of the first adhesive) 2a after photocuring and a second adhesive region (a region composed of the second adhesive) 3a.

[0147] (Step (e)) In step (e), for example, the semiconductor wafers 8 with film-like adhesive obtained by the above-described cutting are separated from each other by extending (expanding) the cutting strip 7, and the semiconductor wafers 8 with film-like adhesive pushed up from the cutting strip 7 side by the needle N are picked up from the film-like adhesive 1a side by the pick-up tool P (see FIG. 8). The picked-up semiconductor wafers 8 with film-like adhesive are transferred to the bonding tool for bonding in step (f).

[0148] (Step (f)) In step (f), for example, firstly, a semiconductor wafer mounting substrate 9 with a connecting portion 12 (second connecting portion) is prepared, and the semiconductor wafer 8 with a film-like adhesive is aligned with the substrate 9. Next, the semiconductor wafer 8 with the film-like adhesive is placed from the film-like adhesive 1a side onto the main surface of the substrate 9 where the connecting portion 10 (wire, bump, etc.) is provided, and then heated to bond the semiconductor wafer 8 with the film-like adhesive and the substrate 9 (see Figures 9(a) and 9(b)). Here, the connecting portion 5 of the semiconductor wafer 8 with the film-like adhesive is electrically connected to the connecting portion 10 of the substrate 9, and a sealing portion 1a' composed of a cured film-like adhesive 1a is formed between the semiconductor wafer A' and the substrate 9. The connecting portion 5 and the connecting portion 10 are sealed, thereby obtaining a bonding body of the semiconductor wafer 8 with the film-like adhesive and the substrate 9, i.e., a semiconductor device 11. The sealing part 1a' has an upper portion 2a' containing a first adhesive and a lower portion 3a' containing a second adhesive.

[0149] When one of the connecting parts 5 and 10 uses a solder bump (for example, when the connecting part 5 or the connecting part 10 is a wiring provided with a solder bump), the connecting part 5 and the connecting part 10 are electrically connected and mechanically connected by soldering.

[0150] The heating in step (f) can be performed simultaneously with or after the semiconductor wafer is configured. The heating and configuration in step (f) can be thermoforming. Step (f) may include: a temporary fixing step after alignment (temporary fixing step); and a step of melting the bumps (e.g., solder bumps) provided on the connector by heat treatment to join the semiconductor wafer A' and the substrate 9 and seal the connector (sealing step). During the temporary fixing stage, since a metal bond is not necessarily formed, the temporary fixing step can be performed under low load, short time, and low temperature. Therefore, by performing the temporary fixing step and the sealing step in step (f), productivity can be improved and degradation of the connector can be suppressed.

[0151] The load applied for temporary fixation should be appropriately set, taking into account factors such as the number of connecting parts (protrusions), the absorption of height deviations of connecting parts (protrusions), and the amount of deformation of connecting parts (protrusions). From the viewpoint of eliminating gaps to facilitate contact with the connecting parts, a larger load is better. For example, a load of 0.009N to 0.2N per connecting part (e.g., protrusion) is preferred.

[0152] Heating during the sealing process can be performed using a device capable of heating the metal at a temperature above the melting point of the joint. The optimal heating temperature is the temperature at which the film adhesive cures, and even better is the temperature at which it is fully cured. Appropriately set the heating temperature and heating time.

[0153] The heating time during the sealing process varies depending on the type of metal constituting the connection, but from a productivity standpoint, a shorter time is better. When solder bumps are used in the connection, a heating time of 20 seconds or less is preferable, 10 seconds or less is even better, and 5 seconds or less is further preferable. For copper-copper or copper-gold metal connections, a connection time of 60 seconds or less is preferable.

[0154] In the sealing process, a device capable of heating and pressurizing can be used to heat and pressurize simultaneously. That is, the heating in the sealing process can be based on heat pressing. In this case, the load (connection load) is set considering the size of the connecting member, the number of connecting parts, height deviation, and the amount of deformation of the connecting part based on pressurization. The connection load can, for example, be greater than atmospheric pressure but less than 1 MPa. From the viewpoint of suppressing voids and improving connectivity, a larger load is better; from the viewpoint of suppressing rounded corners, a smaller load is better. From these perspectives, a load of 0.05~0.5 MPa is preferred. The pressing time (connection time) varies depending on the type of metal constituting the connecting part, but from the viewpoint of improving productivity, a shorter time is better. When the connecting part is a solder bump, a pressing time of 20 seconds or less is preferred, 10 seconds or less is better, and 5 seconds or less is even better. Furthermore, since the heat from a crimping machine is difficult to transfer to the rounded corners when applying direct pressure, it is better to use air pressure for pressurization, considering that the heat can be transferred to the rounded corners more easily and effectively. From the perspective of one-time sealing and suppressing the rounded corners, it is also better to use air pressure (such as pressurization using a pressurized reflow oven or pressurized drying oven) for pressurization during heating.

[0155] After connecting the semiconductor wafer A' and the substrate 9, heat treatment can be performed using an oven or similar means to further improve the reliability of the connection. [Example]

[0156] The present disclosure will be described in more detail below by way of embodiments, but the present disclosure is not limited to the embodiments.

[0157] The details of the materials used in the embodiments are as follows. (Liquid epoxy resin) YX7110B80: Flexible epoxy resin, manufactured by Mitsubishi Chemical Corporation, product name "jER YX7110B80", "jER" is a registered trademark (the same applies hereinafter). YL983U: Bisphenol F type liquid epoxy resin, manufactured by Mitsubishi Chemical Corporation, product name "jER YL983U" (Solid epoxy resin) EP1032: A multifunctional solid epoxy resin containing a pyroxene backbone, manufactured by Mitsubishi Chemical Corporation, product name "jER1032H60". (Imidazole-based curing agent) .2PHZ-PW: 2-Phenylon-4,5-Dihydroxymethylimidazolium, manufactured by SHIKOKU CHEMICALS CORPORATION, product name .2MAOK-PW: 2,4-Diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-tris(2')isocyanuric acid adduct, manufactured by SHIKOKU CHEMICALS CORPORATION, product name (Phenoxy resin) ZX-1356-2: Phenoxy resin, manufactured by Tohto Kasei Co., Ltd., product name, Tg = approximately 71°C, weight average molecular weight Mw = approximately 63,000 (Acrylic compound) A-DPH: Dipentaerythritol Polyacrylate, manufactured by Shin Nakamura Chemical Industry Co., Ltd. (Product Name) (Photopolymerization initiator) Omnirad 184: 1-Hydroxycyclohexylphenyl ketone, manufactured by IGM RESINS BV, product name ("Omnirad" is a registered trademark. The same applies hereinafter). Ominirad 819: Phenylenol bis(2,4,6-trimethylbenzoyl)phosphine oxide, manufactured by IGM Resins BV. Omnirad 127: 2-Hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionic)benzyl)phenyl)-2-methylpropane-1-one, manufactured by IGM Resins BV. (Organic filler) .EXL-2655: Core-shell organic microparticles, manufactured by Dow AgroSciences LLC. (Silica filler) KE180G-HLA: Silica filler, manufactured by Admatechs Co., Ltd. (Product name) (Fluid compound) 2-Methylglutaric acid: Manufactured by Sigma-Aldrich Co. LLC, melting point = approximately 78°C

[0158] <Examples 1-7> (Preparation of the first adhesive film) In the components shown in Table 1, all components except the photopolymerization initiator were added to the organic solvent (methyl ethyl ketone) until the NV value ([mass of paint after drying] / [mass of paint before drying]×100) reached 60%, thus obtaining a mixture. At this point, the amount of each component added was set as shown in Table 1 (unit: parts by mass). Subsequently, Φ1.0 mm and Φ2.0 mm microspheres were added to the above mixture, and the mixture was stirred for 30 minutes using a bead mill (Fritsch Japan Co., Ltd. planetary micro-milling machine P-7). The amount of microspheres added was the same as the mass of the non-volatile components (total amount of components other than the organic solvent) of the mixture. After stirring, the beads were removed by filtration. Next, the amount of photopolymerization initiator shown in Table 1 (unit: parts by mass) was added to the obtained mixture, and the mixture was stirred to obtain coating solutions 1A to 7A for forming the first adhesive layer.

[0159] Using the obtained coating solutions 1A to 7A, first adhesive films (first adhesive films 1A to 7A) each having a first adhesive layer 1A to 7A were obtained. Specifically, firstly, the coating solution was applied to a substrate film (manufactured by Teijin Dupont Film Co., Ltd., product name "Purex A54") using a small precision coating apparatus (Yasui Seiki Inc.) to make the dried film thickness 4.5 μm. Next, the coating film having a first adhesive layer was obtained by drying it in a clean oven (manufactured by ESPEC) (80°C / 10 min).

[0160] [Table 1] The first layer 1A 2A 3A 4A 5A 6A 7A Liquid epoxy resin YX7110B80 2.3 2.4 2.4 2.4 2.5 2.6 2.7 YL983U - - - - - - 3.1 solid epoxy resin EP1032 27.7 28.9 28.9 28.9 29.7 31.4 29.9 Imidazole-based curing agents 2PHZ-PW 1.4 1.4 1.4 - - - - 2MAOK-PW - - - 1.4 1.5 1.6 1.6 phenoxy resin ZX-1356-2 13.8 14.4 14.4 14.4 14.8 15.7 16.5 acrylic compounds A-DPH 10 7.8 7.8 7.8 6.4 3.4 3.6 Photopolymerization initiator Omnirad 184 0.15 - 0.117 - - - - Omnirad 819 0.03 0.117 0.023 0.117 0.1 0.05 - Omnirad 127 - - - - - - 0.1 Organic fillers EXL-2655 4.6 4.8 4.8 4.8 4.9 5.2 5.5 Silica filler KE-180G-HLA 40.1 40.1 40.1 40.1 40.1 40.1 37.0 Epoxy resin: Acrylic compound 7.5:2.5 8:2 8.5:1.5 9.1:0.9

[0161] (Preparation of the second adhesive film) The components shown in Table 2 were added to an organic solvent (methyl ethyl ketone) until the NV value reached 60%, resulting in a mixture. At this point, the amount of each component added was set as shown in Table 2 (unit: parts by mass). Subsequently, Φ1.0 mm and Φ2.0 mm microspheres were added to the mixture, and the mixture was stirred for 30 minutes using a bead mill (Fritsch Japan Co., Ltd. planetary micro-mill P-7). The amount of microspheres added was the same as the mass of the non-volatile components (total amount of components other than the organic solvent) in the mixture. After stirring, the microspheres were removed by filtration, yielding coating solution 1B and coating solution 2B for forming the second adhesive layer.

[0162] The obtained coating liquid 1B was applied to a substrate film (manufactured by Teijin Dupont Film Co., Ltd., product name "Purex A54") using a small precision coating apparatus (Yasui Seiki Inc.) to achieve a film thickness of 4.5 μm after drying. Next, the coating was dried (80°C / 10 min) in a clean oven (manufactured by ESPEC) to obtain a second adhesive film 1B having a second adhesive layer 1B. Furthermore, a second adhesive film 2B having a second adhesive layer 2B was obtained in the same manner, except that coating liquid 2B was used instead of coating liquid 1B.

[0163] [Table 2] The second layer 1B 2B Liquid epoxy resin YX7110B80 6.3 2.9 YL983U 2.8 3.3 solid epoxy resin EP1032 29.9 34.3 Imidazole-based curing agents 2PHZ-PW 1.1 - 2MAOK-PW - 1.2 phenoxy resin ZX-1356-2 13.9 14.4 Organic fillers EXL-2655 5.6 5.8 Silica filler KE-180G-HLA 39.4 37.0 flux compounds 2-Methylglutaric acid 1.1 1.2

[0164] (Preparation of film-like adhesive) The first adhesive layer and the second adhesive layer were laminated by laminating any one of the first adhesive films 1A to 7A and the second adhesive film 1B or 2B prepared above with the combinations shown in Table 3, thus producing film-like adhesives (total thickness 9.0 μm) as described in Examples 1 to 6. The lamination temperature was set to 50°C.

[0165] <Comparative Example 1> After obtaining the second adhesive film 1B having the second adhesive layer 1B in the same manner as the "fabrication of the second adhesive film" in Examples 1 to 6 above, the obtained second adhesive layer 1B was laminated in two layers to obtain the film adhesive of Comparative Example 1 (total thickness 9.0 μm).

[0166] <Evaluation> Using the film-like adhesive obtained in the Examples and Comparative Examples, a connection structure (semiconductor device) was fabricated by following these steps. Furthermore, using the obtained connection structure, connection reliability (initial conductivity), fillet length, voids, and sealing performance were evaluated by the methods shown below. The results are shown in Table 3. Additionally, "-" in the table indicates no evaluation.

[0167] (Construction of connecting structures) The film-like adhesive prepared in the examples and comparative examples was cut to a specified size (8mm length × 8mm width × 9.0μm thickness) to prepare evaluation samples. Next, the evaluation samples were attached to the surface (connection surface) of a semiconductor wafer with solder bumps (wafer dimensions: 7.3mm length × 7.3mm width × 0.15mm thickness, bump height: approximately 40μm for copper pillars + solder, number of bumps: 328) where the solder bumps were located, thus obtaining a laminate of the evaluation sample and the semiconductor wafer with solder bumps. In this example, the semiconductor wafer with solder bumps was attached from the side of the first adhesive layer (the side opposite to the second adhesive layer). Next, using the evaluation sample from the examples, light was irradiated onto the laminate obtained above from the evaluation sample side to photocur the first adhesive layer. The light irradiation was performed using a conveyor belt type ultraviolet irradiation device CS60 (manufactured by GS YUASA). In Examples 1, 3, and 6, the light irradiation dose was set to 500 mJ / cm², and in Examples 2, 4, 5, and 7, the light irradiation dose was set to 250 mJ / cm². Next, using a flip-chip mounting apparatus "FCB3" (manufactured by Panasonic Corporation), the aforementioned laminate (in these examples, the laminate after light irradiation) was mounted from the evaluation sample side onto a glass epoxy substrate (glass epoxy material: 420 μm thick, copper wiring: 9 μm thick). During mounting, the crimping temperature was set to 350°C, the crimping time to 3 seconds, and the crimping pressure to 0.5 MPa. This resulted in a connection structure (semiconductor device) in which a glass epoxy substrate and a semiconductor wafer with solder bumps were daisy-chained together.

[0168] (Connection reliability) The connection reliability (initial conductivity) was evaluated by measuring the connection resistance value of the connection structure obtained above using a multimeter (manufactured by ADVANTEST, product name "R6871E"). A connection resistance value of 60.0Ω or higher but less than 80.0Ω was designated as "A", a connection resistance value greater than 80.0Ω but less than 100Ω was designated as "B", and all cases with connection resistance values ​​greater than 100Ω, less than 60.0Ω, and no resistance value displayed due to poor connection were designated as "C". A rating of B indicates sufficient connection reliability, and a rating of A indicates good connection reliability.

[0169] (Corner radius measurement) Using a VHX-6000 digital microscope (manufactured by KEYENCE CORPORATION), the connection structure obtained above was observed from the semiconductor wafer side, and the lengths of the adhesive overflowing from the four sides of the semiconductor wafer (rounded corners) were measured. The maximum value of the shortest distance from the end of the overflowing adhesive to the semiconductor wafer was used as the rounded corner length for each side. The rounded corner amount was evaluated by averaging the rounded corner lengths measured on each of the four sides. When the average value was less than 100 μm, it was determined that the amount of rounded corners generated was sufficiently reduced. The values ​​in the table represent the average values ​​of the rounded corner lengths.

[0170] (gap) For the connection structure obtained above, appearance images were captured using an ultrasonic imaging diagnostic device (product name "Insight-300", manufactured by INSIGHT INC.), and images of the adhesive layer (a layer composed of a cured film of semiconductor adhesive) on the chip were captured using a GT-9300UF scanner (manufactured by Epson Corp.). Tone correction and dichroism conversion were performed using image processing software Adobe Photoshop (registered trademark) to identify void areas, and the proportion of void areas was calculated using histograms. The area of ​​the adhesive portion on the chip was set to 100%, and the void generation rate was categorized as follows: "A" for less than 5%, "B" for more than 5% but less than 10%, and "C" for more than 10%.

[0171] (Sealing) Using a semiconductor / FPD inspection microscope MX63 (manufactured by OLYMPUS CORPORATION), the connection structure obtained above was observed from the semiconductor wafer side, and the lengths of the unfilled portions at the four corners of the wafer were measured. The length of the unfilled portion was the maximum value of the shortest distance from the four corners of the wafer to the filled area. Regarding sealing performance, a length of less than 500 μm for the unfilled portion was rated as "A", and a length of less than 1,000 μm was rated as "B".

[0172] [Table 3] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 Adhesive 1 1A 2A 3A 4A 5A 6A 7A - Second adhesive 1B 1B 1B 1 B 1B 1B 2B - Corner radius (μm) 57.7 90.7 80.8 69.7 74.6 83.5 85.5 143.9 gap - - - - - A A C Sealing - - - - - A A A

[0173] 1,1a: Film adhesives for semiconductors 2,2a: First adhesive region 3,3a: Second adhesive region 4: Substrate 5: Connecting part (first connecting part) 9: Matrix 10: Connecting part (first connecting part) 11: Semiconductor Devices 15: Wiring (First and Second Connections) 20: Semiconductor wafers 25: Matrix 30: Connecting bump 32: Protrusion (first connecting part and second connecting part) 40: Sealing part 100, 200, 500: Semiconductor devices A: Semiconductor wafer A': Semiconductor wafer

Claims

1. A film-like adhesive for semiconductors, having a first adhesive region and a second adhesive region along its thickness direction, wherein the first adhesive region is photocurable and thermosetting, and the second adhesive region is thermosetting but not photocurable.

2. The semiconductor film adhesive as claimed in claim 1, wherein the first adhesive region contains a photopolymerizable compound, a photopolymerization initiator, a thermosetting resin, and a thermosetting agent.

3. The semiconductor film adhesive as described in claim 2, wherein the aforementioned photopolymerizable compound is a free radical polymerizable compound, and the aforementioned photopolymerization initiator is a photofree radical polymerization initiator.

4. The semiconductor film adhesive as claimed in claim 3, wherein the aforementioned free radical polymerizable compound comprises a (meth)acrylic acid compound.

5. The semiconductor film adhesive as described in claim 2, wherein the aforementioned thermosetting resin comprises an epoxy resin.

6. The semiconductor film adhesive as described in claim 5, wherein the aforementioned thermosetting agent comprises an imidazole-based curing agent.

7. The semiconductor film adhesive as described in claim 6, wherein the aforementioned imidazole-based curing agent has a tri-ring.

8. The semiconductor film adhesive as claimed in claim 2, wherein the ratio of the content of the aforementioned thermosetting resin to the content of the aforementioned photopolymerizable compound in the first adhesive region is 3 to 11 by mass.

9. The semiconductor film adhesive as claimed in claim 1, wherein the aforementioned second adhesive region contains a thermosetting resin, a thermosetting agent, and a flux compound.

10. The semiconductor film adhesive as claimed in claim 9, wherein the aforementioned flux compound has two or more carboxyl groups.

11. The semiconductor film adhesive as claimed in claim 1, wherein the thickness of the second adhesive region is 0.5 to 2 times the thickness of the first adhesive region.

12. The semiconductor film adhesive as claimed in claim 1, used to bond a semiconductor wafer and a substrate, and to seal the gap between the semiconductor wafer and the substrate.

13. A method for manufacturing a semiconductor film adhesive according to any one of claims 1 to 12, comprising: The step of placing one of a first adhesive layer having photocurability and thermosetting properties and a second adhesive layer having thermosetting properties but not photocurability on top of the other.

14. An adhesive tape comprising: a semiconductor film adhesive as described in any one of claims 1 to 12; and a back-abrasion tape disposed on the semiconductor film adhesive and, when viewed from the second adhesive region, on a side opposite to the first adhesive region.

15. A method for manufacturing a semiconductor device, comprising: A photoirradiation step of irradiating light onto the first adhesive region of the semiconductor film adhesive described in any one of claims 1 to 12; The process of heating and bonding a semiconductor wafer and a substrate with their connection portions facing each other, after being irradiated by light, is performed when the aforementioned semiconductor film adhesive is attached from the first adhesive region to the connection surface of the semiconductor wafer or its precursor or the connection surface of the substrate or its precursor.

16. A method for manufacturing a semiconductor device as described in claim 15, further comprising: The steps include: preparing an adhesive tape comprising the aforementioned semiconductor film adhesive and a back-grinding tape disposed on the semiconductor film adhesive and, when viewed from the second adhesive region, on the side opposite to the first adhesive region; a lamination step of attaching the adhesive tape from the semiconductor film adhesive side to the bonding surface of the semiconductor wafer precursor or the substrate precursor; and a back-grinding step of grinding the aforementioned precursor on which the adhesive tape is attached from the side opposite to the adhesive tape.

17. A method for manufacturing a semiconductor device as claimed in claim 16, wherein the aforementioned photoirradiation step is performed after the aforementioned back polishing step and after the aforementioned back polishing tape is removed.

18. A semiconductor device comprising: a semiconductor wafer having a first connection portion; a substrate having a second connection portion electrically connected to the first connection portion; and a sealing portion for joining the semiconductor wafer and the substrate and filling the gap between the semiconductor wafer and the substrate, wherein the sealing portion is a cured product of a semiconductor film adhesive as described in any one of claims 1 to 12.

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