Method for manufacturing semiconductor adhesive films, dicing die bonding films, and semiconductor devices.

Abstract

To provide an adhesive film for semiconductor for forming a cured product which shows a high tensile fracture strength at a high temperature.SOLUTION: An adhesive film 10 is used for gluing a semiconductor chip to a substrate while burying another semiconductor chip mounted on the substrate, or gluing a semiconductor chip to another semiconductor chip while burying part or whole of a wire connected to the other semiconductor chip. The adhesive film 10 comprises a thermosetting component, an elastomer and an inorganic filler. In the adhesive film, the content of the elastomer is 10-30 mass% to a mass of the adhesive film 10, and the content of the inorganic filler is 40-50 mass% to the mass of the adhesive film 10.SELECTED DRAWING: Figure 4

Description

Technical Field

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[0001] The present disclosure relates to an adhesive film for semiconductors, a dicing die bonding film, and a method for manufacturing a semiconductor device using these.

Background Art

[0002] There may be a need to embed wires connected to other semiconductor chips with an adhesive film for bonding a semiconductor chip to a substrate (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One aspect of the present disclosure relates to an adhesive film for semiconductors that forms a cured product exhibiting high tensile fracture strength at high temperatures.

Means for Solving the Problems

[0005] One aspect of this disclosure relates to an adhesive film used for bonding a semiconductor chip to a substrate while embedding other semiconductor chips mounted on the substrate, or for bonding a semiconductor chip to another semiconductor chip while embedding some or all of the wires connected to the other semiconductor chip. In other words, one aspect of this disclosure relates to an application or use of the adhesive film for bonding a semiconductor chip to a substrate while embedding other semiconductor chips mounted on the substrate, or for bonding a semiconductor chip to another semiconductor chip while embedding some or all of the wires connected to the other semiconductor chip. The adhesive film contains a thermosetting component, an elastomer, and an inorganic filler. The elastomer content is 10 to 30% by mass based on the mass of the adhesive film. The inorganic filler content is 40 to 50% by mass based on the mass of the adhesive film.

[0006] Adhesive films used to bond semiconductor chips to substrates while embedding other semiconductor chips are sometimes called FOD (Film Over Die) adhesive films and are embedded adhesive films. Adhesive films used to bond semiconductor chips to other semiconductor chips while embedding part or all of the wires connected to those chips are sometimes called FOW (Film Over Wire) adhesive films and are embedded adhesive films.

[0007] Another aspect of this disclosure relates to a method for manufacturing a semiconductor device, which includes bonding a second semiconductor chip to a substrate on which a first semiconductor chip is mounted using the adhesive film. The first semiconductor chip is embedded by the adhesive film.

[0008] Another aspect of this disclosure relates to a method for manufacturing a semiconductor device, comprising bonding a second semiconductor chip to a first semiconductor chip with the adhesive film. The first semiconductor chip is embedded by the adhesive film. [Effects of the Invention]

[0009] A semiconductor adhesive film is provided that forms a cured product exhibiting high tensile breaking strength at temperatures exceeding 100°C. By using this adhesive film, for example, as a FOW film or FOD film, it is possible to manufacture a semiconductor device that suppresses the decrease in reliability associated with the embedding of wires and / or semiconductor chips and has high resistance to thermal shock. Semiconductor devices manufactured using FOW films or FOD films are prone to a decrease in reliability due to effects such as warping or cracks in the adhesive film, but this decrease in reliability can be effectively suppressed by using an adhesive film according to one aspect of this disclosure. By using an adhesive film with excellent embedding properties, the occurrence of warping caused by insufficient embedding can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic cross-sectional view showing an example of an adhesive film. [Figure 2] This is a schematic cross-sectional view showing an example of a laminated sheet having an adhesive film. [Figure 3] This is a schematic cross-sectional view showing an example of a laminated sheet having an adhesive film. [Figure 4] This is a schematic cross-sectional view showing an example of a semiconductor device. [Figure 5] This is a process diagram showing an example of a method for manufacturing a semiconductor device. [Figure 6] This is a process diagram showing an example of a method for manufacturing a semiconductor device. [Figure 7] This is a process diagram showing an example of a method for manufacturing a semiconductor device. [Figure 8] This is a process diagram showing an example of a method for manufacturing a semiconductor device. [Figure 9] This is a process diagram showing an example of a method for manufacturing a semiconductor device. [Figure 10] This is a schematic cross-sectional view showing another example of a semiconductor device. [Figure 11] This is a schematic cross-sectional view showing another example of a semiconductor device. [Modes for carrying out the invention]

[0011] The present invention is not limited to the following examples. In the following examples, the components (including steps, etc.) are not essential unless specifically stated. The sizes of the components in each figure are conceptual, and the relative size relationships between the components are not limited to those shown in each figure. The numerical values and ranges exemplified below also do not limit the present disclosure.

[0012] In this specification, the numerical range indicated by "~" represents a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described stepwise in this specification, the upper limit value or lower limit value described in one numerical range may be replaced with the upper limit value or lower limit value of another stepwise numerical range. In the numerical ranges described in this specification, the upper limit value or lower limit value of the numerical range may be replaced with the value shown in the examples.

[0013] In this specification, (meth)acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl group, (meth)acrylic copolymer, etc.

[0014] FIG. 1 is a schematic cross-sectional view showing an example of an adhesive film. The adhesive film 10 shown in FIG. 1 can be a film formed from a thermosetting adhesive containing a thermosetting component, an elastomer, and an inorganic filler. The adhesive film 10 may be in a semi-cured (B-stage) state.

[0015] (a) Thermosetting component The thermosetting component is a compound having a functional group that forms a crosslinked structure by a thermosetting reaction and includes (a1) a thermosetting resin. The thermosetting component may further include (a2) a curing agent that reacts with the thermosetting resin. From the viewpoint of adhesiveness, the thermosetting resin may include an epoxy resin which is a compound having an epoxy group. In that case, the curing agent may include a phenol resin which is a compound having a phenolic hydroxyl group.

[0016] The content of the thermosetting component (total content of the thermosetting resin and the curing agent) may be 20 to 45% by mass based on the mass of the adhesive film 10. The content of the thermosetting component may be 21% by mass or more, 22% by mass or more, 23% by mass or more, 24% by mass or more, 25% by mass or more, 26% by mass or more, 27% by mass or more, or 28% by mass or more, and may be 44% by mass or less, 43% by mass or less, 42% by mass or less, 41% by mass or less, 40% by mass or less, 39% by mass or less, 38% by mass or less, 37% by mass or less, 36% by mass or less, or 35% by mass or less based on the mass of the adhesive film 10.

[0017] Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin, stilbene type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, triphenol phenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, and diglycidyl ether compounds derived from polyfunctional phenol compounds or polycyclic aromatic compounds (such as anthracene). These may be used alone or in combination of two or more. From the viewpoints of the tackiness and flexibility of the adhesive film, the epoxy resin may be a cresol novolac type epoxy resin, bisphenol F type epoxy resin, bisphenol A type epoxy resin, or a combination thereof.

[0018] The thermosetting resin may include a liquid epoxy resin that is liquid at 25°C. The liquid epoxy resin content may be 5 to 15% by mass based on the mass of the adhesive film 10. The thermosetting resin may also include an epoxy resin that has a softening point of less than 30°C. Adhesive films containing these epoxy resins tend to have good flexibility, and the embedding of semiconductor chips and wires by the adhesive film is further improved. The thermosetting resin may also include an epoxy resin that has a softening point of 50°C or higher.

[0019] Examples of phenolic resins used as curing agents include novolac-type phenolic resins obtained by condensing or co-condensing phenols such as phenol, cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and / or naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthalene with compounds having an aldehyde group such as formaldehyde under an acidic catalyst; phenolic aralkyl resins and naphthol aralkyl resins synthesized from phenols such as allylated bisphenol A, allylated bisphenol F, allylated naphthalenediol, phenol novolac, and / or naphthols with dimethoxyp-xylene or bis(methoxymethyl)biphenyl. These may be used individually or in combination of two or more. The phenolic resin may be a phenolic aralkyl resin, a naphthol aralkyl resin, or a combination thereof.

[0020] The hydroxyl group equivalent of the phenolic resin may be 70 g / eq or more, or 70 to 300 g / eq. When the hydroxyl group equivalent of the phenolic resin is 70 g / eq or more, the storage modulus of the adhesive film tends to increase further. When the hydroxyl group equivalent of the phenolic resin is 300 g / eq or less, foaming and outgassing can be further suppressed.

[0021] When a thermosetting resin contains an epoxy resin and a curing agent contains a phenolic resin, the ratio of the epoxy equivalent of the epoxy resin to the hydroxyl group equivalent of the phenolic resin (epoxy equivalent:hydroxyl group equivalent) may be 0.30 / 0.70 to 0.70 / 0.30, 0.35 / 0.65 to 0.65 / 0.35, 0.40 / 0.60 to 0.60 / 0.40, or 0.45 / 0.55 to 0.55 / 0.45 from the viewpoint of curability. When the equivalent ratio is 0.30 / 0.70 or higher, more sufficient curability tends to be obtained. When the equivalent ratio is 0.70 / 0.30 or lower, it is possible to prevent the viscosity from becoming too high and obtain more sufficient fluidity.

[0022] The softening point of the curing agent may be 50 to 200°C, or 60 to 150°C. Curing agents with a softening point of 200°C or lower tend to have good compatibility with thermosetting resins.

[0023] (b) Elastomer The elastomer can be, for example, a polymer compound exhibiting a glass transition temperature (Tg) of 55°C or lower. Examples of component (b) include acrylic resins, polyester resins, polyamide resins, polyimide resins, silicone resins, butadiene resins, acrylonitrile resins, and modified versions thereof.

[0024] The elastomer content may be 10 to 30% by mass based on the mass of the adhesive film 10. The elastomer content may be 11% or more by mass, 12% or more by mass, 13% or more by mass, 14% or more by mass, 15% or more by mass, 16% or more by mass, 17% or more by mass, 18% or more by mass, 19% or more by mass, 20% or more by mass, or 21% or more by mass, and may be 29% or less by mass, 28% or less by mass, 27% or less by mass, 26% or less by mass, 25% or less by mass, or 24% or less by mass. If the adhesive film contains two or more types of elastomers, their total amount is the elastomer content.

[0025] From the viewpoint of fluidity, the elastomer may contain an acrylic resin. Here, acrylic resin means a polymer containing monomer units derived from (meth)acrylic acid ester. The content of constituent units derived from (meth)acrylic acid ester in the acrylic resin may be, for example, 70% or more by mass, 80% or more by mass, or 90% or more by mass, based on the total amount of acrylic resin. The acrylic resin may contain monomer units derived from (meth)acrylic acid ester having crosslinkable functional groups such as epoxy groups, alcoholic or phenolic hydroxyl groups, and carboxyl groups. The acrylic resin may also be acrylic rubber, which is a copolymer containing (meth)acrylic acid ester and acrylonitrile as monomer units.

[0026] The glass transition temperature (Tg) of an elastomer (e.g., acrylic resin) may be -50°C or higher, -30°C or higher, 0°C or higher, or 3°C or higher, and may be 50°C or lower, 45°C or lower, 40°C or lower, 35°C or lower, 30°C or lower, or 25°C or lower. A low Tg of the elastomer tends to result in adhesive films with good flexibility. Adhesive films with good flexibility are easier to bond to semiconductor wafers while sufficiently eliminating voids, and chipping during dicing due to reduced adhesion can also be suppressed. The glass transition temperature (Tg) refers to the value measured using a DSC (Differential Scanning Calorimeter) (e.g., Rigaku Corporation's "Thermo Plus 2"). The Tg of the elastomer can be adjusted to a desired range by adjusting the type and content of the constituent units that make up the elastomer (in the case of acrylic resin, constituent units derived from (meth)acrylic acid ester).

[0027] The weight-average molecular weight (Mw) of an elastomer (e.g., acrylic resin) may be 100,000 or more, 200,000 or more, or 300,000 or more, and may be 3,000,000 or less, 2,000,000 or less, or 1,000,000 or less. When the Mw of the elastomer is within this range, the film-forming properties and the strength, flexibility, and tackiness of the adhesive film can be appropriately controlled, and the reflowability and embedding properties can be improved. Mw refers to the value calculated using a calibration curve based on standard polystyrene, measured by gel permeation chromatography (GPC).

[0028] Examples of commercially available acrylic resins include SG-70L, SG-708-6, WS-023 EK30, SG-280 EK23, HTR-860P-3CSP, HTR-860P-3CSP-30B (all manufactured by Nagase ChemteX Corporation), and H-CT-865 (manufactured by Showa Denko Materials Corporation).

[0029] (c) Inorganic filler The inorganic filler may be at least one selected from, for example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, boron nitride, and silica. From the viewpoint of adjusting the melt viscosity, the inorganic filler may also contain silica.

[0030] The average particle size of the inorganic filler may be 0.01 μm or larger, or 0.03 μm or larger, from the viewpoint of fluidity, and may also be 1.5 μm or smaller, 1.0 μm or smaller, 0.8 μm or smaller, 0.08 μm or smaller, or 0.06 μm or smaller. Two or more inorganic fillers with different average particle sizes may be combined. Here, the average particle size refers to the particle size with a cumulative frequency of 50% in the particle size distribution determined by the laser diffraction-scattering method. The average particle size of the inorganic filler can also be determined by using an adhesive film containing the inorganic filler. In this case, the residue obtained by heating the adhesive film to decompose the resin components is dispersed in a solvent to prepare a dispersion, and the average particle size of the inorganic filler can be determined from the particle size distribution obtained by applying the laser diffraction-scattering method to this dispersion.

[0031] The adhesive film may contain (c1) a first inorganic filler and (c2) a second inorganic filler that satisfy all of the following conditions. By containing components (c1) and (c2) in the adhesive film, embeddability can be improved, and furthermore, tensile strength can be improved after curing. The average particle size of component (c1) is 300-1000 nm. The average particle size of component (c2) is 0.05 to 0.70 times that of component (c1). The total content of components (c1) and (c2) is 30-60% by mass, based on the total amount of adhesive film.

[0032] The average particle size of component (c1) is 300 to 1000 nm, and may be 350 nm or more, 400 nm or more, or 450 nm or more, and may be 900 nm or less, 800 nm or less, 700 nm or less, or 600 nm or less.

[0033] The average particle size of component (c2) may be less than 300 nm, and may be 250 nm or less, 220 nm or less, or 200 nm or less. The average particle size of component (C2) may be, for example, 10 nm or more, 50 nm or more, or 100 nm or more.

[0034] In this specification, the average particle sizes of components (c1) and (c2) refer to the particle size at which the cumulative frequency is 50% in the particle size distribution determined by laser diffraction-scattering. The average particle sizes of components (c1) and (c2) can also be determined by using an adhesive film containing components (c1) and (c2). In this case, a dispersion is prepared by dispersing the residue obtained by heating the adhesive film to decompose the resin components in a solvent, and from the particle size distribution obtained by applying laser diffraction-scattering to this dispersion, the value of the peak in the range of 300 to 1000 nm can be taken as the average particle size of component (c1), and the value of the peak in the range of less than 300 nm can be taken as the average particle size of component (c2).

[0035] The average particle size of component (c2) is 0.05 to 0.70 times that of component (c1). The average particle size of component (c2) may be 0.10 times or more, 0.20 times or more, or 0.30 times or more, and may be 0.60 times or less, 0.50 times or less, or 0.40 times or less, compared to the average particle size of component (c1).

[0036] (c1) The content of component may be 5 to 40% by mass based on the total amount of adhesive film, and may be 6% or more by mass, 8% or more by mass, or 10% or more by mass, and may be 35% or less by mass, 32% or less by mass, or 30% or less by mass.

[0037] (c2) The content of component may be 10 to 50% by mass, based on the total amount of adhesive film, and may be 15% or more by mass, 18% or more by mass, or 20% or more by mass, and may be 45% or less by mass, 42% or less by mass, or 40% or less by mass.

[0038] The total content of component (c1) and component (c2) is 30 to 60% by mass based on the total amount of adhesive film, and may be 35% or more by mass, 40% or more by mass, or 45% or more by mass, and may be 55% or less by mass, 52% or less by mass, or 50% or less by mass.

[0039] The content of component (c1) may be 10 to 70% by mass, based on the total content of components (c1) and (c2), and may be 15% by mass or more, 18% by mass or more, or 20% by mass or more, and may be 65% by mass or less, 62% by mass or less, or 60% by mass or less.

[0040] The content of component (c2) may be 30 to 90% by mass, based on the total content of component (c1) and component (c2), and may be 35% by mass or more, 38% by mass or more, or 40% by mass or more, and may be 85% by mass or less, 82% by mass or less, or 80% by mass or less.

[0041] The inorganic filler content may be 40 to 50% by mass, based on the total mass of the adhesive film 10. The inorganic filler content may be 41% or more by mass, or 42% or more by mass, or 49% or less by mass, based on the total mass of the adhesive film 10.

[0042] (d) Coupling agent The adhesive film 10 may further contain a coupling agent. The coupling agent may be a silane coupling agent. Examples of silane coupling agents include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane. These may be used individually or in combination of two or more.

[0043] (e) Curing accelerator The adhesive film 10 may further contain a curing accelerator that promotes the curing reaction of the thermosetting component. Examples of curing accelerators include imidazole and its derivatives, organophosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used individually or in combination of two or more. From the viewpoint of reactivity, the curing accelerator may be imidazole or its derivatives. Examples of imidazole derivatives include 2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-methylimidazole. These may be used individually or in combination of two or more.

[0044] The adhesive film 10 may further contain other components as needed. Examples of other components include pigments, ion capture agents, and antioxidants.

[0045] The thickness of the adhesive film 10 may be, for example, 1 μm or more, 3 μm or more, 20 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 50 μm or more, or 60 μm or more, and may also be 200 μm or less, 150 μm or less, 120 μm or less, 80 μm or less, or 60 μm or less. If the adhesive film 10 is an adhesive film for FOW, it may be, for example, 20 to 120 μm, 30 to 80 μm, or 50 to 60 μm in order to embed the wires so that they do not come into contact with the semiconductor chip. If the adhesive film 10 is an adhesive film for FOD, the thickness of the adhesive film 10 may be, for example, 40 to 200 μm, 60 to 150 μm, or 100 to 120 μm in order to properly embed the entire semiconductor chip (e.g., controller chip).

[0046] The adhesive film 10 may have a minimum melt viscosity of 2000 Pa·s or more in the range of 60 to 150°C. If the minimum melt viscosity is 20000 Pa·s or more, the overflow (bleed) of the adhesive film from the semiconductor chip edge can be effectively suppressed. The adhesive film 10 may have a minimum melt viscosity of 200000 Pa·s or less in the range of 60 to 150°C. Here, the minimum melt viscosity is the lowest value of the shear viscosity measured under the conditions in the examples described later, in the range of 60 to 150°C.

[0047] The adhesive film 10 may have a shear viscosity of 35,000 Pa·s or less at 60°C. A shear viscosity of 35,000 Pa·s or less at 60°C tends to improve the embedding properties of the adhesive film. Similarly, the shear viscosity of the adhesive film 10 at 60°C may be 34,000 Pa·s or less, 33,000 Pa·s or less, 32,000 Pa·s or less, 31,000 Pa·s or less, or 30,000 Pa·s or less. It may also be 10,000 Pa·s or more. The shear viscosity here refers to the value measured under the conditions described in the examples below.

[0048] The adhesive film 10 cured by heating may exhibit a tensile breaking strength of 7 MPa or more at 125°C. An adhesive film exhibiting a high tensile breaking strength at 125°C after curing can provide a semiconductor device with high resistance to thermal shock. The tensile breaking strength of the cured adhesive film 10 at 125°C may be 100 MPa or less. The tensile modulus here can be a value measured using a test specimen of adhesive film 10 cured by heating at 110°C for 1 hour, followed by heating at 175°C for 5 hours.

[0049] The storage modulus of the cured adhesive film 10 at 150°C may be 1000 MPa or less, 500 MPa or less, or 300 MPa or less, and may be 10 MPa or more, 15 MPa or more, or 20 MPa or more. When the storage modulus of the adhesive film 10 at 150°C after curing is 1000 MPa or less, it tends to adequately embed the chip, wire, or semiconductor substrate and suppress warping. When the storage modulus of the adhesive film at 150°C after curing is 10 MPa or more, it tends to suppress overhang from the edges of the semiconductor chip during bonding.

[0050] The adhesive film 10 may be used, for example, as a protective sheet to protect the back surface of a semiconductor element in a flip-chip semiconductor device, or as a sealing sheet to seal the space between the surface of a semiconductor element in a flip-chip semiconductor device and the adherend.

[0051] The adhesive film 10 may be supplied in the form of a laminated sheet as illustrated in Figure 2 or Figure 3. The laminated sheet 100 shown in Figure 2 comprises a base material 20 and an adhesive film 10 provided on the base material 20. The laminated sheet 110 shown in Figure 3 further comprises a protective film 30 provided on the side of the adhesive film 10 opposite to the base material 20.

[0052] The base material 20 may be a resin film, and examples include films of polytetrafluoroethylene, polyethylene, polypropylene, polymethylpentene, polyethylene terephthalate, or polyimide. The thickness of the resin film used as the base material 20 may be, for example, 60 to 200 μm or 70 to 170 μm.

[0053] The base material 20 may be a dicing film. A laminated sheet in which the base material 20 is a dicing film can be used as a dicing die bonding film. The dicing die bonding film may be in tape form.

[0054] Examples of dicing films include resin films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. The dicing film may be a resin film whose surface has been treated by primer application, UV treatment, corona discharge treatment, polishing treatment, or etching treatment as needed. The dicing film may be adhesive. An adhesive dicing film may be, for example, a resin film to which adhesiveness has been imparted, or a laminate having a resin film and an adhesive layer provided on one side thereof. The adhesive layer can be formed from a pressure-sensitive or UV-curable adhesive. A pressure-sensitive adhesive is an adhesive that exhibits a certain level of adhesiveness with short-term pressure. A radiation-curable adhesive is an adhesive that has the property of decreasing adhesiveness upon irradiation with radiation (e.g., ultraviolet light). The thickness of the adhesive layer can be appropriately set according to the shape and dimensions of the semiconductor device, but may be, for example, 1 to 100 μm, 5 to 70 μm, or 10 to 40 μm. The thickness of the substrate 20, which is the dicing film, may be 60 to 150 μm or 70 to 130 μm, from the viewpoint of economy and ease of handling of the film.

[0055] The protective film 30 may be a resin film similar to the base material 20. The thickness of the protective film 30 may be, for example, 15 to 200 μm or 70 to 170 μm.

[0056] Semiconductor device and method for manufacturing the same Figure 4 is a schematic cross-sectional view showing an example of a semiconductor device manufactured using an adhesive film. The semiconductor device 200 mainly consists of a substrate 14, a first semiconductor chip Wa and a second semiconductor chip Waa mounted on the substrate 14, a sealing layer 42 that seals the second semiconductor chip Waa, and an adhesive film 10 that adheres the second semiconductor chip Waa to the substrate 14. The substrate 14 has an organic substrate 90 and circuit patterns 84, 94 provided on the organic substrate 90. The first semiconductor chip Wa is bonded to the substrate 14 by adhesive 41. A first wire 88 is connected to the first semiconductor chip Wa, and the first semiconductor chip Wa is electrically connected to the circuit pattern 84 via the first wire 88. The entire first semiconductor chip Wa and the entire first wire 88 are embedded in the adhesive film 10. A second wire 98 is connected to the second semiconductor chip Waa, and the second semiconductor chip Waa is electrically connected to the circuit pattern 84 via the second wire 98. The entirety of the second semiconductor chip Waa and the entirety of the second wire 98 are embedded in the encapsulation layer 42.

[0057] Figures 5, 6, 7, 8, and 9 are process diagrams showing an example of a method for manufacturing the semiconductor device 200 shown in Figure 4. The method shown in Figures 5 to 9 includes bonding a first semiconductor chip Wa to a substrate 14 via an adhesive 41, providing a first wire 88 to connect the first semiconductor chip Wa to the substrate 14 (circuit pattern 84), preparing an adhesive-coated chip having a second semiconductor chip Wbb and an adhesive film 10 attached thereto, pressing the adhesive-coated chip to the substrate 14, thereby bonding the second semiconductor chip Waa to the substrate 14 such that the first semiconductor chip Wa and the first wire 88 are embedded by the adhesive film 10, and providing a second wire 98 to connect the second semiconductor chip Waa to the substrate 14 (circuit pattern 84). Subsequently, by forming a sealing layer 44, the semiconductor device 200 shown in Figure 4 is obtained.

[0058] The thickness of the first semiconductor chip Wa may be 10 to 170 μm. The first semiconductor chip Wa may be a controller chip for driving the semiconductor device 200. The first semiconductor chip Wa may be a flip-chip type chip. The size of the first semiconductor chip Wa is usually less than or equal to the size of the second semiconductor chip Waa. The adhesive 41 interposed between the first semiconductor chip Wa and the substrate 14 can be a standard semiconductor adhesive.

[0059] The adhesive-bonded chip, consisting of a second semiconductor chip Waa and an adhesive film 10, can be prepared, for example, using a dicing die bonding film having a similar configuration to the laminated sheet 100 illustrated in Figure 2. In this case, for example, the laminated sheet 100 (dicing die bonding film) is attached to one side of a semiconductor wafer with the adhesive film 10 facing the semiconductor wafer. The side to which the adhesive film 10 is attached may be the circuit side of the semiconductor wafer or the opposite back side. By dividing the semiconductor wafer to which the laminated sheet 100 (dicing die bonding film) is attached by dicing, individual pieces of the second semiconductor chip Waa are formed. Examples of dicing include blade dicing using a rotary blade and a method of cutting the adhesive film 10 together with the semiconductor wafer using a laser. After dicing, the adhesive strength of the dicing film may be reduced by ultraviolet irradiation. The second semiconductor chip Waa is picked up together with the divided adhesive film 10.

[0060] The second semiconductor chip Waa may have a width of 20 mm or less. The width (or length of one side) of the second semiconductor chip Waa may be 3 to 15 mm, or 5 to 10 mm.

[0061] The semiconductor wafer used to form the second semiconductor chip Waa may be, for example, a thin semiconductor wafer having a thickness of 10 to 100 μm. The semiconductor wafer may be made of single-crystal silicon, polycrystalline silicon, various ceramics, or compound semiconductors such as gallium arsenide. The second semiconductor chip Waa can also be formed from a similar semiconductor wafer.

[0062] As shown in Figure 7, an adhesive chip consisting of an adhesive film 10 and a second semiconductor chip Waa is placed such that the first wire 88 and the first semiconductor chip Waa are covered by the adhesive film 10. Next, as shown in Figure 8, the second semiconductor chip Waa is fixed to the substrate 14 by pressing it onto the substrate 14. The heating temperature for pressing may be 50 to 200°C or 100 to 150°C. Higher heating temperatures for pressing tend to improve embeddability as the adhesive film 3 becomes softer. The pressing time may be 0.5 to 20 seconds or 1 to 5 seconds. The pressure for pressing may be 0.01 to 5 MPa or 0.02 to 2 MPa.

[0063] After pressing, the structure including the adhesive film 10 may be further heated to cure the adhesive film 10. The temperature and time for this can be appropriately set depending on the curing temperature of the adhesive film 10, etc. The temperature may be changed in stages. The heating temperature may be, for example, 40 to 300°C or 60 to 200°C. The heating time may be, for example, 30 to 300 minutes.

[0064] As shown in Figure 9, the substrate 14 and the second semiconductor chip Waa are electrically connected via the second wire 98. The second wire 98 may be, for example, a gold wire, an aluminum wire, or a copper wire. The heating temperature for connecting the second wire 98 may be in the range of 80 to 250°C or 80 to 220°C. The heating time for connecting the second wire 98 may be several seconds to several minutes. For connecting the second wire 98, vibration energy by ultrasound and crimping energy by applied pressure may be applied. The type and connection method of the first wire 88 may be the same as that of the second wire 98.

[0065] Subsequently, a sealing layer 42 is formed from the sealing material to enclose the circuit pattern 84, the second wire 98, and the second semiconductor chip Waa. The sealing layer 42 can be formed, for example, by a conventional method using a mold. After the sealing layer 42 is formed, the adhesive film 10 and the sealing layer 42 may be further heat-cured by heating. The heating temperature for this purpose may be, for example, 165 to 185°C, and the heating time may be about 0.5 to 8 hours.

[0066] Figure 10 is a schematic cross-sectional view showing another example of a semiconductor device manufactured using an adhesive film. The semiconductor device 201 shown in Figure 10 mainly consists of a substrate 14, a first semiconductor chip Wa and a second semiconductor chip Waa mounted on the substrate 14, a sealing layer 42 that seals the first semiconductor chip Wa and the second semiconductor chip Waa, and an adhesive film 10 that adheres the second semiconductor chip Waa to the first semiconductor chip Wa. The substrate 14 has an organic substrate 90, a circuit pattern 84 provided on the organic substrate 90, and connection terminals 95 provided on the surface of the organic substrate 90 opposite to the circuit pattern 84. The first semiconductor chip Wa is bonded to the substrate 14 by adhesive 41. A first wire 88 is connected to the first semiconductor chip Wa, and the first semiconductor chip Wa is electrically connected to the circuit pattern 84 via the first wire 88. A portion of the first wire 88 is embedded in the adhesive film 10. The second semiconductor chip Waa is connected to the second wire 98, and the second semiconductor chip Waa is electrically connected to the circuit pattern 84 via the second wire 98.

[0067] The semiconductor device 201 shown in Figure 10 can be manufactured by a method similar to that used for manufacturing the semiconductor device 200, which includes bonding a second semiconductor chip Waa to a first semiconductor chip Wa using an adhesive film 10.

[0068] Figure 11 is a schematic cross-sectional view showing another example of a semiconductor device manufactured using an adhesive film. The semiconductor device 202 shown in Figure 11 mainly consists of a substrate 14 (organic substrate 90), a first semiconductor chip Wa and a second semiconductor chip Waa mounted on the substrate 14, a sealing layer 42 that seals the first semiconductor chip Wa and the second semiconductor chip Waa, and an adhesive film 10 that adheres the second semiconductor chip Waa to the substrate 14 while embedding the entire first semiconductor chip Wa. The first semiconductor chip Wa is a flip-chip type chip and is electrically connected to the substrate 14 via a plurality of electrodes 96. An underfill 50 is filled between the first semiconductor chip Wa and the substrate 14. [Examples]

[0069] The present invention is not limited to the following embodiments.

[0070] 1. Preparation of adhesive film (1) Raw materials The following ingredients were prepared. (a1) Thermosetting resin (epoxy resin) • N-500P-10 (Product name, manufactured by DIC Corporation, o-cresol novolac type epoxy resin, epoxy equivalent: 204 g / eq, softening point: 75~85°C) EXA-830CRP (product name, manufactured by DIC Corporation, liquid bisphenol F type epoxy resin, epoxy equivalent: 159g / eq) EXA-4816 (product name, manufactured by DIC Corporation, liquid bisphenol A type epoxy resin, epoxy equivalent: 400g / eq) jER YX-7110B80 (product name, manufactured by Mitsubishi Chemical Corporation, liquid epoxy resin, epoxy equivalent: 900~1200g / eq) (a2) Hardener (phenol resin) • MEH-7800M (product name, manufactured by Meiwa Chemical Co., Ltd., phenyl aralkyl type phenolic resin, hydroxyl group equivalent: 174 g / eq, softening point: 80°C) • PSM-4326 (product name, manufactured by Gun-ei Chemical Co., Ltd., phenol novolac resin, hydroxyl group equivalent: 105g / eq) (b) Elastomer • Acrylic resin A (HTR-860P-3CSP (product name, manufactured by Nagase ChemteX Corporation, weight-average molecular weight: 800,000, Tg: 12℃)) • Acrylic resin B (polymer of butyl acrylate / ethyl acrylate / ethyl methacrylate / glycidyl methacrylate / styrene, weight-average molecular weight: 400,000, Tg: 5℃) (c) Inorganic filler • Inorganic filler A (SC2050-HLG (product name), manufactured by Admatex Co., Ltd., silica filler dispersion, average particle size: 0.50 μm) • Inorganic filler B (silica filler dispersion, average particle size: 0.18 μm) (d) Coupling agent • A-189 (product name, manufactured by GE Toshiba Silicone Co., Ltd., γ-mercaptopropyltrimethoxysilane) (e) Curing accelerator • 2PZ-CN (product name, manufactured by Shikoku Chemicals Co., Ltd., 1-cyanoethyl-2-phenylimidazole)

[0071] (2) Adhesive Varnish Adhesive varnishes for the examples or comparative examples were prepared, each containing (a1) a thermosetting resin, (a2) a curing agent, (b) an elastomer, (c) an inorganic filler, (d) a silane coupling agent, and (e) a curing accelerator in the proportions (parts by mass) shown in Table 1 or Table 2. The proportions of the inorganic filler shown in the table represent the amount of solids (silica filler). First, a mixture containing (a1) a thermosetting resin, (a2) a curing agent, (c) an inorganic filler, and cyclohexanone was stirred. Then, (a) an elastomer was added and the mixture was stirred. After that, (d) a coupling agent and (e) a curing accelerator were added and the mixture was stirred until all components were homogeneous to obtain the adhesive varnishes for Examples 1-8 and Comparative Examples 1-3. Each adhesive varnish was filtered through a 100-mesh filter and degassed under vacuum.

[0072] (3) Adhesive film A 38 μm thick polyethylene terephthalate (PET) film with a release treatment was prepared as a support film. Each adhesive varnish was applied to the support film. The coating was dried in two stages by heating at 90°C for 5 minutes, followed by 140°C for 5 minutes, to form a B-stage adhesive film (60 μm thick) on the support film.

[0073] 2. Evaluation (1) Shear viscosity and minimum melt viscosity of the adhesive film Multiple adhesive films were bonded together at 80°C to form a laminate with a thickness of 1 ± 0.05 mm. A measurement sample with a circular surface and a diameter of 9 mm was punched out from the laminate. The measurement sample was mounted on a circular aluminum plate jig with a diameter of 8 mm. The shear viscosity of the measurement sample was measured using an ARES (manufactured by T.A. Instrument Japan Co., Ltd.) under the following conditions. From the measurement results, the shear viscosity at 60°C and the minimum shear viscosity (minimum melt viscosity) within the range of 60 to 150°C were read. Measurement conditions ·Measurement temperature: 35~160℃ • Heating rate: 5°C / min Distortion: 5% • Frequency: 4.4Hz ·Initial load: 10g

[0074] (2) Tensile breaking strength of the cured adhesive film Adhesive films were bonded together at 80°C to form a laminate with a thickness of approximately 120 μm. A dumbbell-shaped test specimen was cut from the laminate and cured by heating at 110°C for 1 hour, followed by 175°C for 5 hours. Tensile tests were performed on the cured test specimens under the following conditions. The tensile breaking strength was determined from the stress at the time the test specimen fractured. Measurement conditions Distance between fixtures: 80mm Measurement temperature: 125℃ Tensile speed: 300 mm / min

[0075] (3) TCT resistance Fabrication of evaluation semiconductor devices The evaluation semiconductor device was fabricated using the following procedure. A dicing die bonding film (adhesive film thickness: 10 μm, dicing adhesive film thickness: 110 μm, manufactured by Showa Denko Materials Co., Ltd.) comprising an adhesive film and a dicing adhesive film was prepared. A 40 μm thick semiconductor wafer was attached to this dicing die bonding film with the adhesive layer in contact with the semiconductor wafer, at a stage temperature of 70°C. The semiconductor wafer attached to the dicing die bonding film was cut using a fully automatic dicer DFD-6361 (manufactured by Disco Corporation) to form a chip with a size of 2 mm x 5 mm (first semiconductor chip). The first semiconductor chip and the adhesive layer attached thereto were picked up using a die bonder DB830Plus+ (manufactured by Fasford Technology Co., Ltd.), and the first semiconductor chip was pressed onto a glass epoxy substrate (organic substrate) having a dummy circuit via the adhesive layer. The position where the first semiconductor chip was pressed was adjusted to the center of the dummy circuit.

[0076] Each adhesive film (60 μm thick) from the examples or comparative examples was bonded together to form an adhesive film with a thickness of 120 μm. This was bonded to a dicing adhesive film (110 μm thick, manufactured by Showa Denko Materials Co., Ltd.) to produce a dicing die bonding film. This dicing die bonding film was attached to a semiconductor wafer (180 μm thick). The semiconductor wafer attached to the dicing die bonding film was cut together with the adhesive film to form a chip (second semiconductor chip) with a size of 8 mm x 8 mm. The second semiconductor chip and the adhesive film attached to it were picked up, and the second semiconductor chip was pressed onto an organic substrate via the adhesive film so as to cover the first semiconductor chip. The position of the second semiconductor chip was adjusted so that the first semiconductor chip was located in the center of the bottom of the second semiconductor chip. Subsequently, an adhesive film (20 μm thick) and a dicing adhesive film (110 μm thick, manufactured by Showa Denko Materials Co., Ltd.) were bonded together to produce a dicing die bonding film. This dicing die bonding film was attached to a semiconductor wafer (thickness: 110 μm). The semiconductor wafer attached to the dicing die bonding film was cut together with the adhesive film to form chips measuring 8 mm x 8 mm (the third to sixth semiconductor chips). The third to sixth semiconductor chips and the adhesive film attached to them were picked up, and the third to sixth semiconductor chips were pressed onto the top of the second semiconductor chip in the order starting from the third semiconductor chip, thereby forming a laminate in which the first semiconductor chip, the second semiconductor chip, and the third to sixth semiconductor chips were stacked. The formed laminate was molded using a compression molding machine (PMC1040-S, manufactured by TOWA Corporation) to obtain an evaluation semiconductor device (molding temperature: 175°C, post-molding curing: 175°C (5 hours)).

[0077] The fabricated evaluation semiconductor devices were subjected to a cycle test involving repeated temperature conditions of -65°C for 15 minutes and 150°C for 15 minutes. After 600 cycles, the evaluation semiconductor devices were observed, and their TCT resistance was evaluated according to the following criteria. OK: No cracks have occurred in the adhesive film. NG: Cracks appear in the adhesive film.

[0078] [Table 1]

[0079] [Table 2]

[0080] The evaluation results are shown in Tables 1 and 2. The adhesive films of each example showed significantly higher tensile breaking strength at high temperatures compared to the adhesive film of the comparative example. Furthermore, the semiconductor devices having semiconductor elements bonded using the adhesive films of each example showed excellent TCT resistance. [Explanation of Symbols]

[0081] 10...Adhesive film, 14...Substrate, 20...Base material (dicing film), 30...Protective film, 41...Adhesive, 42...Sealing layer, 84, 94...Circuit pattern, 88...First wire, 90...Organic substrate, 98...Second wire, 100, 110...Laminated sheet, 200, 201, 202...Semiconductor equipment, Wa...First semiconductor chip, Waa...Second semiconductor chip.

Claims

1. A semiconductor adhesive film used for bonding a semiconductor chip to a substrate while embedding other semiconductor chips mounted on the substrate, or for bonding a semiconductor chip to another semiconductor chip while embedding part or all of the wires connected to the other semiconductor chip, The adhesive film contains a thermosetting component, an elastomer, and an inorganic filler. The content of the thermosetting component is 20 to 30% by mass, based on the mass of the adhesive film. The elastomer content is 10 to 24% by mass, based on the mass of the adhesive film. The inorganic filler content is 40 to 50% by mass, based on the mass of the adhesive film. The thermosetting component includes a liquid epoxy resin that is liquid at 25°C, and the content of the liquid epoxy resin is 5 to 15% by mass based on the mass of the adhesive film. Adhesive film for semiconductors.

2. The semiconductor adhesive film according to claim 1, wherein the adhesive film exhibits a minimum melt viscosity of 2000 Pa·s or more in the range of 60 to 150°C, and a shear viscosity of 35000 Pa·s or less at 60°C.

3. The semiconductor adhesive film according to claim 1 or 2, wherein the adhesive film, cured by heating at 110°C for 1 hour and then at 175°C for 5 hours, exhibits a tensile breaking strength of 7 MPa or more at 125°C.

4. Dicing film and A semiconductor adhesive film according to any one of claims 1 to 3 is provided on the dicing film, A dicing die bonding film equipped with [a specific feature].

5. The method includes bonding a second semiconductor chip to a substrate on which a first semiconductor chip is mounted using a semiconductor adhesive film described in any one of claims 1 to 4. The first semiconductor chip is embedded by the adhesive film. A method for manufacturing semiconductor devices.

6. The method includes bonding a second semiconductor chip to a first semiconductor chip using an adhesive film described in any one of claims 1 to 4. A wire is connected to the first semiconductor chip. A portion or all of the wire is embedded by the adhesive film. A method for manufacturing semiconductor devices.

7. The method according to claim 5 or 6, wherein the first semiconductor chip is a controller chip.

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