Adhesives for semiconductors, adhesive tapes, methods for manufacturing semiconductor devices, and semiconductor devices.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- RESONAC CORP
- Filing Date
- 2024-12-19
- Publication Date
- 2026-07-01
AI Technical Summary
The challenge in semiconductor manufacturing is the need for adhesives with low minimum melt viscosity and slow curing properties to ensure reliable connections between components with narrow gaps and pitches, as traditional thermosetting adhesives can trap hardened material between connecting parts if curing occurs prematurely.
A semiconductor adhesive composed of a thermosetting resin, a curing agent, a thermoplastic resin, and a filler, incorporating epoxy resins that are solid or liquid at 30°C, with specific ring structures and glycidyloxy groups, and optionally a flux compound, to achieve low melt viscosity and controlled curing.
The adhesive provides reliable connections by preventing trapped cured material and reducing voids, improving sealing and connectivity while maintaining low viscosity and slow curing, enhancing the reliability of semiconductor devices.
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Abstract
Description
[Technical Field]
[0001] This disclosure relates to adhesives for semiconductors, adhesive tapes, methods for manufacturing semiconductor devices, and semiconductor devices. [Background technology]
[0002] Traditionally, wire bonding, which uses thin metal wires such as gold wires, has been widely applied to connect semiconductor chips and substrates. On the other hand, in order to meet the demands for higher functionality, higher integration, and higher speed for semiconductor devices, the flip-chip connection method (FC connection method), which directly connects the semiconductor chip and substrate by forming conductive protrusions called bumps on the semiconductor chip or substrate, is becoming widespread.
[0003] For example, the COB (Chip On Board) connection method, which is widely used in BGA (Ball Grid Array) and CSP (Chip Size Package) for connecting semiconductor chips and substrates, also falls under the category of FC connection methods. Furthermore, FC connection methods are also widely used in COC (Chip On Chip) connection methods, which connect semiconductor chips by forming connection points (e.g., bumps and wiring) on the semiconductor chip.
[0004] Furthermore, in packages where further miniaturization, thinning, and high functionality are strongly demanded, chip stack packages, POP (Package On Package), and TSV (Through-Silicon Via), which stack chips in multiple layers using the aforementioned connection methods, are beginning to become widely adopted. Such stacking and multi-layering technologies allow for smaller packages compared to two-dimensional arrangement methods because semiconductor chips are arranged three-dimensionally. In addition, they are effective in improving semiconductor performance, reducing noise, reducing mounting area, and saving power, and are attracting attention as next-generation semiconductor wiring technologies.
[0005] Furthermore, from the perspective of improving productivity, COW (Chip On Wafer), which involves crimping (connecting) semiconductor chips onto a semiconductor wafer and then separating them to create a semiconductor package, is also attracting attention. In addition, from a similar perspective, the gang bonding method, which involves aligning and temporarily crimping multiple semiconductor chips onto a semiconductor wafer or map substrate, and then permanently crimping these multiple semiconductor chips together to secure the connection, is also attracting attention.
[0006] Thermosetting adhesives are sometimes used to connect connecting members as described above (for example, connecting a semiconductor chip to a substrate, or connecting semiconductor chips to each other) (see, for example, Patent Document 1). Thermosetting adhesives harden when heated during connection (pressure), but if the adhesive hardens before the connecting parts of the connecting members come into contact due to pressure, hardened adhesive material will get trapped between the connecting parts, resulting in a faulty connection. Therefore, the adhesive needs to exhibit sufficient fluidity at the time of connection. [Prior art documents] [Patent Documents]
[0007] [Patent Document 1] Japanese Patent Publication No. 2008-294382 [Overview of the project] [Problems that the invention aims to solve]
[0008] In recent years, with the increasing functionality and integration of packaging, the gaps between connecting components and the pitch between wiring have become narrower. Therefore, there is a need for the development of adhesives that have a sufficiently low minimum melt viscosity and slow curing properties.
[0009] Therefore, the main objective of this disclosure is to provide a semiconductor adhesive that has a sufficiently low minimum melt viscosity and slow curing properties. [Means for solving the problem]
[0010] The present disclosure provides at least the following [1] to
[19] .
[0011] [1] A semiconductor adhesive containing a thermosetting resin, a curing agent, a thermoplastic resin, and a filler, where the thermosetting resin includes an epoxy resin that is solid at 30°C and an epoxy resin that is liquid at 30°C, where the epoxy resin that is solid at 30°C includes a compound having a structure in which two or more rings selected from an aliphatic ring and an aromatic ring are directly bonded, and a monocyclic aromatic ring in which at least one hydrogen atom is substituted with a glycidyloxy group. [2] The semiconductor adhesive according to [1], where the compound has at least one structure selected from the group consisting of a dicyclopentadiene structure, a naphthalene structure, and a biphenyl structure. [3] The semiconductor adhesive according to [1] or [2], where the epoxy resin that is solid at 30°C includes at least one compound represented by the following formulas (1-1) to (1-2). [Chemical formula] [In formula (1-1), X represents a divalent group including a structure in which two or more rings selected from an aliphatic ring and an aromatic ring are directly bonded, L represents a single bond or a methylene group, R 1 represents an alkyl group having 1 to 4 carbon atoms, n1 represents an integer from 1 to 10, and m represents an integer from 0 to 3. A plurality of Xs may be the same as or different from each other, a plurality of Ls may be the same as or different from each other, a plurality of R 1 s may be the same as or different from each other, and a plurality of ms may be the same as or different from each other.] [Chemical formula] [In formula (1-2), X, L, R 1and m has the same meaning as described above, and n2 represents an integer of 1 to 10. A plurality of Xs may be the same as or different from each other, a plurality of Ls may be the same as or different from each other, and a plurality of Rs 1 may be the same as or different from each other, and a plurality of ms may be the same as or different from each other.] [4] The semiconductor adhesive according to any one of [1] to [3], wherein the epoxy resin that is liquid at 30 °C contains a compound represented by the following formula (2-1). [Chemical formula] [In formula (2-1), R 11 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 12 represents a glycidyl group, p represents an integer of 0 to 4, and q represents an integer of 0 or more. A plurality of Rs 11 may be the same as or different from each other, a plurality of Rs 12 may be the same as or different from each other, a plurality of ps may be the same as or different from each other, and a plurality of qs may be the same as or different from each other.] [5] The semiconductor adhesive according to any one of [1] to [4], wherein the content of the epoxy resin that is solid at 30 °C is 30 to 42% by mass based on the total mass of the semiconductor adhesive. [6] The semiconductor adhesive according to any one of [1] to [5], wherein the content of the epoxy resin that is liquid at 30 °C is 1 to 20% by mass based on the total mass of the semiconductor adhesive. [7] The semiconductor adhesive according to any one of [1] to [6], wherein the curing agent contains an imidazole-based curing agent. [8] The semiconductor adhesive according to any one of [1] to [7], wherein the content of the curing agent is 0.5 to 5% by mass based on the total mass of the semiconductor adhesive. [9] The semiconductor adhesive according to any one of [1] to [8], wherein the thermoplastic resin contains a phenoxy resin.
[10] The semiconductor adhesive according to any one of [1] to [9], wherein the filler comprises silica.
[11] A semiconductor adhesive according to any one of [1] to
[10] , further containing a flux compound.
[12] The semiconductor adhesive according to
[11] , comprising the flux compound a carboxylic acid.
[13] A semiconductor adhesive according to any of [1] to
[12] , wherein the melt viscosity at 80°C is less than 20,000 Pa·s.
[14] A non-conductive semiconductor adhesive as described in any of [1] to
[13] .
[15] A semiconductor adhesive according to any one of [1] to
[14] , used for joining a semiconductor chip to a substrate and sealing the gap between the semiconductor chip and the substrate.
[16] A semiconductor adhesive, which is in the form of a film, as described in any of [1] to
[15] .
[17] A film-like adhesive comprising the semiconductor adhesive described in
[16] , An adhesive tape comprising an adhesive tape provided on the aforementioned film-like adhesive.
[18] A method for manufacturing a semiconductor device, comprising the step of heating and joining a semiconductor chip and a substrate in a state where their connection portions face each other via a semiconductor adhesive described in any of [1] to
[15] .
[19] The device comprises a semiconductor chip 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 chip and the substrate and fills the gap between the semiconductor chip and the substrate. A semiconductor device wherein the sealing portion is a cured product of a semiconductor adhesive described in any of [1] to
[15] . [Effects of the Invention]
[0012] According to this disclosure, it is possible to provide a semiconductor adhesive that has a sufficiently low minimum melt viscosity and slow curing properties. [Brief explanation of the drawing]
[0013] [Figure 1] Figure 1 is a schematic cross-sectional view showing one embodiment of the semiconductor adhesive of this disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view showing one embodiment of the semiconductor device of the present disclosure. [Figure 3] Figure 3 is a schematic cross-sectional view showing another embodiment of the semiconductor device of the present disclosure. [Figure 4] Figure 4 is a schematic cross-sectional view illustrating one embodiment of the method for manufacturing a semiconductor device according to the present disclosure. [Figure 5] Figure 5 is a schematic cross-sectional view illustrating one embodiment of the method for manufacturing a semiconductor device according to the present disclosure. [Figure 6] Figure 6 is a schematic cross-sectional view illustrating one embodiment of the method for manufacturing a semiconductor device according to the present disclosure. [Figure 7] Figure 7 is a schematic cross-sectional view illustrating one embodiment of the method for manufacturing a semiconductor device according to the present disclosure. [Figure 8] Figure 8 is a schematic cross-sectional view illustrating one embodiment of the method for manufacturing a semiconductor device according to the present disclosure. [Modes for carrying out the invention]
[0014] In this specification, "(meth)acrylic" means at least one of acrylic and its corresponding methacrylic. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylate." Numerical ranges indicated with "~" indicate a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In addition, in numerical ranges described in this specification, the upper or lower limits of the numerical range may be replaced with the values shown in the examples. Furthermore, the upper and lower limits described individually can be combined in any way. In addition, unless otherwise specified, the materials exemplified below may be used individually or in combination of two or more. The content of each component in the composition means the total amount of the multiple substances present in the composition if there are multiple substances corresponding to each component in the composition, unless otherwise specified.
[0015] The embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted. Furthermore, unless otherwise specified, positional relationships such as top, bottom, left, and right are based on the positional relationships shown in the drawings. Moreover, the dimensional ratios in the drawings are not limited to those shown.
[0016] <Semiconductor adhesives> One embodiment of a semiconductor adhesive (hereinafter sometimes simply referred to as "adhesive") contains a thermosetting resin (hereinafter sometimes referred to as "component (A)"), a curing agent (hereinafter sometimes referred to as "component (B)"), a thermoplastic resin (hereinafter sometimes referred to as "component (C)"), and a filler (hereinafter sometimes referred to as "component (D)"), wherein the thermosetting resin includes an epoxy resin that is solid at 30°C and an epoxy resin that is liquid at 30°C, and the epoxy resin that is solid at 30°C has a structure in which two or more rings selected from aliphatic rings and aromatic rings are directly bonded, and also has a monocyclic aromatic ring in which at least one hydrogen atom is substituted with a glycidyloxy group.
[0017] In this specification, "for semiconductors" means used for connecting (bonding) and sealing connecting members such as semiconductor chips. The semiconductor adhesive of this embodiment is suitably used for bonding a semiconductor chip to a substrate and sealing the gap between the semiconductor chip and the substrate.
[0018] In this specification, "epoxy resin that is solid at 30°C" means an epoxy resin whose viscosity at 30°C, as measured by an E-type viscometer, is greater than 10,000 Pa·s or immeasurable. Furthermore, "epoxy resin that is liquid at 30°C" means an epoxy resin whose viscosity at 30°C, as measured by an E-type viscometer, is 10,000 Pa·s or less.
[0019] The semiconductor adhesive described above is, for example, an adhesive composition containing components (A) to (D). Because the semiconductor adhesive contains components (A) to (D), it has a sufficiently low minimum melt viscosity and slow curing properties. Therefore, even if the surface of the connection part is covered with the adhesive when the semiconductor adhesive is placed between connecting members, the adhesive is easily removed by heating, and it is difficult for cured adhesive material to remain between the connection parts after connection. Thus, the semiconductor adhesive can improve the connection reliability of semiconductor devices. Furthermore, the semiconductor adhesive can also reduce the amount of voids generated and improve good sealing properties (adhesive filling properties).
[0020] The minimum melt viscosity of semiconductor adhesives is, for example, less than 2000 Pa·s, and may be 1500 Pa·s or less, or 1000 Pa·s or less. The lower limit of the above minimum melt viscosity is, for example, 100 Pa·s, 150 Pa·s, or 200 Pa·s. In other words, the minimum melt viscosity of semiconductor adhesives may be 100 Pa·s or more and less than 2000 Pa·s, 150 to 1500 Pa·s, or 200 to 1000 Pa·s.
[0021] The temperature at which semiconductor adhesives exhibit their lowest melt viscosity (melting temperature) is, for example, 110-180°C, and may be 120-175°C, 140-170°C, or 150-160°C. The lower the melting temperature, the faster the adhesive tends to harden, and the higher the melting temperature, the slower the adhesive tends to harden.
[0022] The above minimum melt viscosity and melt temperature are values measured, for example, using a rotary rheometer under the following conditions. [conditions] • Measurement sample shape: Film with a thickness of 400 μm and a diameter of 10 mm. • Measuring tool size: 8mmφ • Heating rate: 10°C / min • Frequency: 10Hz Temperature range: 30~165℃ The measurement sample may be prepared, for example, by creating a 5 μm thick film, laminating it until it reaches a thickness of 400 μm, and then punching out the resulting laminate using a Φ10 mm punch. The lamination conditions may be a device setting temperature of 60°C and a device transport speed of level 3.
[0023] The amount of heat generated at the peak of the DSC curve for semiconductor adhesives (DSC heat generation) is, for example, 70-170 J / g, and can be 80-160 J / g, 100-150 J / g, 70-130 J / g, or 70-100 J / g. The smaller the DSC heat generation, the slower the curing of the adhesive tends to be, and the larger the DSC heat generation, the faster the curing of the adhesive tends to be.
[0024] The peak top temperature (DSC peak temperature) of the exothermic peak in the DSC curve of semiconductor adhesives is, for example, 130-190°C, and can be 140-180°C, 160-170°C, or 164-169°C. The lower the DSC peak temperature, the faster the curing of the adhesive tends to be, and the higher the DSC peak temperature, the slower the curing of the adhesive tends to be.
[0025] The DSC calorific value and DSC peak temperature can be determined from a DSC curve obtained by performing differential scanning calorimetry (DSC) under conditions such as a nitrogen atmosphere, a heating rate of 10°C / min, and a measurement temperature range of 30 to 300°C. The DSC calorific value can be determined by using a partial area analysis method and specifying the baseline of the analysis temperature range and integrating the peak area by instructing the analysis to be performed within the temperature range of 110°C to 220°C on the DSC curve. The DSC peak temperature can be determined by instructing the analysis to be performed within the temperature range of 110°C to 220°C. In some cases, multiple exothermic peaks may exist in the DSC curve. In this case, the DSC calorific value is the total exothermic value obtained from the multiple peaks, and the DSC peak temperature is the highest peak top temperature. A film with a thickness of 400 μm and a diameter of 5 mm may be used as the measurement sample. The measurement sample may be prepared, for example, by creating a 5 μm thick film, laminating it until it reaches a thickness of 400 μm, and then punching out the resulting laminate using a Φ5 mm punch.
[0026] Incidentally, metal bonding is generally used to connect connecting members in order to ensure sufficient connection reliability (e.g., insulation reliability). The main metals used for the connection parts of connecting members (e.g., bumps and wiring) include solder, tin, gold, silver, copper, nickel, etc., and conductive materials containing multiple types of these are also used. On the surface of the connection part, impurities may be generated due to the oxidation of the above metals to form an oxide film, and due to the adhesion of impurities such as oxides. If such impurities remain, there is a concern that the connection reliability between connecting members will decrease, and the advantages of adopting the above-mentioned connection method will be lost. Therefore, from the viewpoint of removing the above-mentioned oxide film and impurities, the semiconductor adhesive of one embodiment may further contain a flux compound (hereinafter sometimes referred to as "component (E)").
[0027] The adhesive for semiconductor in one embodiment may have a melt viscosity at 80°C of less than 20,000 Pa·s. When the melt viscosity of the adhesive for semiconductor at 80°C is less than 20,000 Pa·s, effects such as improvement in sealing property, suppression of void generation, and improvement in lamination property to a wafer can be easily obtained. The melt viscosity of the adhesive for semiconductor at 80°C may be, for example, 1000 Pa·s or more and less than 20,000 Pa·s, and may be 1500 - 10,000 Pa·s or 2000 - 5000 Pa·s. The adhesive for semiconductor having the melt viscosity as described above can be produced, for example, by adjusting the amount of filler. The melt viscosity at 80°C can be measured in the same manner as the measurement method of the minimum melt viscosity described above.
[0028] The adhesive for semiconductor in one embodiment may be non-conductive. That is, the adhesive for semiconductor in one embodiment may be a so-called NCF (Non Conductive Film). From the viewpoint of using a non-conductive adhesive for semiconductor, it is preferable not to use a conductive filler as the (D) component. Here, non-conductive means that the electrical conductivity is 10 -5 S / m or less.
[0029] FIG. 1 is a schematic cross-sectional view showing an adhesive for semiconductor (film-like adhesive for semiconductor) in one embodiment. As shown in FIG. 1, the adhesive for semiconductor in one embodiment may be in the form of a film. The film-like adhesive for semiconductor may be composed of an adhesive composition containing the above (A) to (D) components, and may have a region (region A) composed of the adhesive composition containing the above (A) to (D) components and a region (region B) composed of another adhesive composition. When the adhesive for semiconductor has a plurality of regions, the fluidity of the entire adhesive during connection can be changed by adjusting the thickness, composition, etc. of region A. Region A and region B may be present side by side in the thickness direction of the film-like adhesive. Region A and region B may be layers. That is, region A and region B arranged in the thickness direction of the film-like adhesive may extend along the main surface direction of the film-like adhesive. A plurality of region A and region B may exist respectively.
[0030] The thickness of the film-like adhesive may be 1 to 50 μm, and may also be 3 to 50 μm, 4 to 30 μm, or 5 to 20 μm.
[0031] The thickness of the film-like adhesive may be set appropriately in relation to the connection portion of the connecting member. If the sum of the heights of the connection portions is x and the thickness of the film-like adhesive is y, the relationship between x and y may satisfy 0.70x ≤ y ≤ 1.3x and 0.80x ≤ y ≤ 1.2x from the viewpoint of connectivity during pressing and adhesive filling properties.
[0032] The film-like adhesive may have a substrate such as a support film or protective film on one or both of its main surfaces. In this disclosure, a laminate comprising a substrate and a film-like adhesive provided on the substrate is referred to as an "adhesive tape".
[0033] As the base material, any base material exemplified as a base material used in the method for manufacturing a film-like adhesive described later can be used. The base material may be an adhesive tape, and the adhesive tape may be a backgrind tape. A preferred embodiment of the present disclosure is an adhesive tape (adhesive tape with adhesive tape) comprising an adhesive tape and a film-like adhesive provided on the adhesive tape. The adhesive tape with adhesive tape may be an adhesive tape with a backgrind tape.
[0034] Adhesive tape (backgrind tape) is usually configured so that one main surface is the adhesive layer. However, in adhesive tape, the adhesive tape is placed on a film-like adhesive so that the adhesive layer and the film-like adhesive are in contact. The thickness of the base material (for example, the thickness of the adhesive tape (backgrind tape)) may be 20 to 300 μm.
[0035] The adhesive tape may be a laminate of a substrate and a film-like adhesive obtained by the method of manufacturing a film-like adhesive described later, that is, by applying a coating liquid to a substrate, forming a coating film, and drying it. Alternatively, it may be a laminate obtained by attaching a substrate to a film-like adhesive (for example, laminating the film-like adhesive and the substrate). If the substrate is an adhesive tape (backgrind tape), applying and drying the coating liquid on the adhesive layer of the adhesive tape (backgrind tape) may cause problems such as destruction of the adhesive layer and migration of components between the adhesive and the adhesive. Therefore, the adhesive tape may be obtained by attaching the adhesive tape (backgrind tape) to a film-like adhesive.
[0036] Next, we will explain the components that may be included in semiconductor adhesives. In the following explanation, "adhesive" may be read as "adhesive composition."
[0037] ((A) component: thermosetting resin) Component (A) is a component that hardens by forming three-dimensional bonds between molecules when heated or otherwise. Examples of component (A) include epoxy resin, polyimide resin, and phenolic resin.
[0038] Component (A) contains an epoxy resin. The epoxy resin is a compound having one or more epoxy groups in its molecule, or it may be a compound having two or more epoxy groups in its molecule. As the epoxy resin, from the viewpoint of suppressing decomposition and generation of volatile components when bonding at high temperatures, a compound with a thermal weight loss rate of 5% or less at 250°C may be used, or a compound with a thermal weight loss rate of 5% or less at 300°C may be used. The epoxy resin content in component (A) may be 80% by mass or more, or 90% by mass or more, based on the total amount of component (A). The epoxy resin content may be 100% by mass, based on the total amount of component (A).
[0039] Component (A) includes an epoxy resin that is solid at 30°C (hereinafter sometimes referred to as "component (A1)") and an epoxy resin that is liquid at 30°C (hereinafter sometimes referred to as "component (A2)").
[0040] [(A1) component] Component (A1) includes compounds having a structure in which two or more rings selected from aliphatic rings and aromatic rings are directly bonded (hereinafter sometimes referred to as a "polycyclic structure"), and monocyclic aromatic rings in which at least one hydrogen atom is substituted with a glycidyloxy group (hereinafter sometimes simply referred to as a "monocyclic aromatic ring") (hereinafter sometimes referred to as "compound (X)"). In the above context, both aliphatic rings and aromatic rings mean a single ring.
[0041] The above polycyclic structure may be a structure in which two or more rings are directly bonded together by sharing one or more atoms (e.g., a spiro structure, a fused ring structure, a bridged ring structure), or a structure in which two or more rings are directly bonded together by single bonds (e.g., a biphenyl structure, a bicyclohexyl structure). Compound (X) may have one of these structures alone or in combination of two or more.
[0042] The aliphatic ring may be an aliphatic hydrocarbon ring and may contain heteroatoms such as oxygen, nitrogen, and sulfur. Examples of aliphatic rings include cyclopentane rings, cyclohexane rings, cycloheptane rings, cyclooctane rings, and tricyclodecane rings.
[0043] The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle. Examples of aromatic rings include benzene rings, furan rings, pyrrole rings, and thiophene rings.
[0044] The number of directly bonded rings (two or more) may be 2 to 5, or 2 to 4 or 2 to 3. The two or more directly bonded rings may be identical or different.
[0045] Examples of polycyclic structures include norbornane, decalin, adamantane, dicyclopentadiene, naphthalene, biphenyl, indole, quinoline, benzofuran, and benzothiophene structures. From the viewpoint of excellent heat resistance, the polycyclic structure may be at least one structure selected from the group consisting of dicyclopentadiene, naphthalene, and biphenyl structures. In particular, the above effect is especially pronounced when the polycyclic structure is a dicyclopentadiene structure.
[0046] A monocyclic aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle. Examples of monocyclic aromatic rings include benzene rings, furan rings, pyrrole rings, and thiophene rings.
[0047] The number of glycidyloxy groups (the number of hydrogen atoms substituted with glycidyloxy groups) in a monocyclic aromatic ring may be 1 to 3, or it may be 1 to 2 or 1.
[0048] The monocyclic aromatic ring may have substituents other than the glycidyloxy group. These substituents may, for example, be alkyl groups having 1 to 4 carbon atoms. Specific examples of alkyl groups include methyl, ethyl, propyl, and butyl groups. The number of substituents other than the glycidyloxy group may be 0 to 3, or 0 to 2 or 0 to 1.
[0049] A monocyclic aromatic ring may be included in compound (X) as a monovalent group represented by the following formula (I), or as a divalent group represented by the following formula (II). [ka] [ka]
[0050] R in equations (I) and (II) 1* represents substituents other than the glycidyloxy group, m represents an integer from 0 to 3, and * represents a bond. Multiple R 1 These groups may be identical or different from each other. Details of substituents other than the glycidyloxy group are as described above. When compound (X) has a group of formula (I) or formula (II) above, optimal slow curing properties are easily obtained.
[0051] Monocyclic aromatic rings may be included in the polycyclic structure described above, but in this case, it is preferable that the polycyclic structure includes a structure in which two or more rings are directly bonded together by sharing one or more atoms.
[0052] (A1) Component (X) may include at least one compound represented by the following formulas (1-1) to (1-2) as compound (X) from the viewpoint of easily obtaining optimal slow curing properties. [ka] [ka]
[0053] In formulas (1-1) and (1-2), X represents a divalent group containing a structure in which two or more rings selected from aliphatic and aromatic rings are directly bonded, L represents a single bond or a methylene group, and R 1 The 'm' represents a substituent other than the glycidyloxy group, and 'm' represents an integer from 0 to 3. Details of substituents other than the glycidyloxy group are as described above, for example, alkyl groups having 1 to 4 carbon atoms.
[0054] In equation (1-1), n1 represents an integer from 1 to 10. In equation (1-1), multiple X values may be the same or different from each other, multiple L values may be the same or different from each other, and multiple R values may be different from each other. 1 The elements m may be the same or different from each other, and multiple m elements may be the same or different from each other.
[0055] In equation (1-2), n² represents an integer from 1 to 10. n² may also be from 1 to 5. In equation (1-2), multiple X values may be the same or different from each other, multiple L values may be the same or different from each other, and multiple R values may be the same or different from each other. 1 The elements m may be the same or different from each other, and multiple m elements may be the same or different from each other.
[0056] The softening point of compound (X) may be 40°C or higher, 50°C or higher, 60°C or higher, 70°C or higher, or 80°C or higher, from the viewpoint of improving the handling of the film-like adhesive at room temperature (e.g., 25°C), and may be 100°C or lower, 90°C or lower, 80°C or lower, 70°C or lower, or 60°C or lower, from the viewpoint of improving the lamination properties of the film-like adhesive to silicon wafers and adhesion to cover films. From these viewpoints, the softening point of compound (X) may be 40-100°C, 50-90°C, 60-80°C, 70-100°C, 80-100°C, 40-70°C, or 40-60°C. The softening point is a value measured by the ring-sphere method in accordance with JIS K7234:1986.
[0057] The ICI viscosity of compound (X) at 150°C may be 0.01 Pa·s or higher, 0.05 Pa·s or higher, 0.1 Pa·s or higher, or 0.5 Pa·s or higher from the viewpoint of reducing the amount of volatile components, and may be 1 Pa·s or lower, 0.5 Pa·s or lower, 0.1 Pa·s or lower, or 0.05 Pa·s or lower from the viewpoint of improving fluidity. From these viewpoints, the ICI viscosity of compound (X) at 150°C may be 0.01 to 1 Pa·s, 0.05 to 0.5 Pa·s, 0.1 to 1 Pa·s, 0.5 to 1 Pa·s, 0.01 to 0.1 Pa·s, or 0.01 to 0.05 Pa·s. ICI viscosity is a value measured by an ICI viscometer.
[0058] From the viewpoint of improving curability, the content of compound (X) may be 30% by mass or more, 32% by mass or more, or 34% by mass or more, based on the total amount of adhesive. From the viewpoint of improving stress relaxation and reducing the coefficient of linear expansion, the content of compound (X) may be 42% by mass or less, 39% by mass or less, or 35% by mass or less, based on the total amount of adhesive. From these viewpoints, compound (X) may be 30-42% by mass, 32-39% by mass or 34-35% by mass, based on the total amount of adhesive.
[0059] Component (A1) may consist only of compound (X), or it may contain components other than compound (X). The proportion of compound (X) in component (A1) may be 90% by mass or more, and may be 95% by mass or more, or 98% by mass or more.
[0060] The epoxy equivalent of component (A1) may be 100 to 3000 g / eq, and may also be 100 to 2000 g / eq, 100 to 1500 g / eq, 100 to 400 g / eq, or 150 to 300 g / eq. When the epoxy equivalent is within the above range, a good balance between reactivity and fluidity during heating is easily achieved. From the same viewpoint as above, the epoxy equivalent of compound (X) may also be within the above range.
[0061] From the viewpoint of improving curability, the content of component (A1) may be 30% by mass or more, 32% by mass or more, or 34% by mass or more, based on the total amount of adhesive. From the viewpoint of improving stress relaxation and reducing the coefficient of linear expansion, the content of component (A1) may be 42% by mass or less, 39% by mass or less, or 35% by mass or less, based on the total amount of adhesive. From these viewpoints, the content of component (A1) may be 30-42% by mass, 32-39% by mass or 34-35% by mass, based on the total amount of adhesive.
[0062] [(A2) component] (A2) Examples of components include bisphenol A type glycidyl ether, bisphenol AD type glycidyl ether, bisphenol S type glycidyl ether, bisphenol F type glycidyl ether, water-added bisphenol A type glycidyl ether, ethylene oxide adduct bisphenol A type glycidyl ether, propylene oxide adduct bisphenol A type glycidyl ether, naphthalene resin glycidyl ether, trifunctional or tetrafunctional glycidylamines, etc.
[0063] Component (A2) also contributes to suppressing the occurrence of cracks and fissures on the film surface when semiconductor adhesives are made into films. Component (A2) may include a compound represented by the following formula (2-1) from the viewpoint of further reducing melt viscosity and further suppressing the occurrence of cracks and fissures on the film surface. [ka]
[0064] In formula (2-1), R 11 R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 12 represents a glycidyl group, p represents an integer from 0 to 4, and q represents an integer greater than or equal to 0. Multiple R 11 These may be the same or different from each other, and there may be multiple R 12 The elements p may be identical or different from each other, multiple p may be identical or different from each other, and multiple q may be identical or different from each other.
[0065] R 11 The number of carbon atoms in the alkyl group represented by may be 1 to 4 or 1 to 2. The alkyl group may be linear, branched, or cyclic. Examples of alkyl groups include methyl group, ethyl group, n-propyl group, n-butyl group, n-hexyl group, n-octyl group, iso-propyl group, iso-butyl group, sec-butyl group, tert-butyl group, 2-ethylhexyl group, cyclopentyl group, and cyclohexyl group.
[0066] p may be an integer between 0 and 3 or between 0 and 1. q may be an integer between 0 and 10, between 0 and 5 or between 0 and 3.
[0067] The content of the compound represented by formula (2-1) may be 1% by mass or more, 2% by mass or more, or 3% by mass or more, based on the total amount of adhesive, from the viewpoint of further reducing melt viscosity and further suppressing the occurrence of cracks and fissures on the film surface. The content of the compound represented by formula (2-1) may be 20% by mass or less, 15% by mass or less, or 10% by mass or less, based on the total amount of adhesive, from the viewpoint of easily suppressing excessive tackiness of the film adhesive and easily suppressing edge fusion. From these perspectives, the content of the compound represented by formula (2-1) may be 1 to 20% by mass, 2 to 15% by mass, or 3 to 10% by mass, based on the total amount of adhesive.
[0068] Component (A2) may consist only of the compound represented by formula (2-1), and may also contain components other than the compound represented by formula (2-1). The proportion of the compound represented by formula (2-1) in component (A2) may be 20% by mass or more, 30% by mass or more, or 40% by mass or more, and may be 100% by mass or less, 80% by mass or less, or 60% by mass or less, and may be 20 to 100% by mass, 30 to 80% by mass, or 40 to 60% by mass.
[0069] The epoxy equivalent of component (A2) may be 100 to 3000 g / eq, and may also be 100 to 2000 g / eq, 100 to 1500 g / eq, 100 to 400 g / eq, or 150 to 300 g / eq. When the epoxy equivalent is within the above range, a good balance between reactivity and fluidity during heating is easily achieved. From a similar viewpoint, the epoxy equivalent of the compound represented by formula (2-1) may also be within the above range.
[0070] In one embodiment, component (A2) may include a compound having an epoxy equivalent of 100 to 400 g / eq (hereinafter referred to as "compound (Y1)") and a compound having an epoxy equivalent of 600 to 3000 g / eq (hereinafter referred to as "compound (Y2)"). In this case, toughness tends to improve. The epoxy equivalent of compound (Y1) may be 150 to 300 g / eq from the viewpoint of optimizing the curing speed of the adhesive. The epoxy equivalent of compound (Y2) may be 700 to 1500 g / eq from the viewpoint of increasing toughness. Compound (Y1) may be a compound represented by the above formula (2-1) from the viewpoint of ensuring the flexibility of the film-like adhesive.
[0071] The content of compound (Y1) may be 1% by mass or more, 2% by mass or more, or 3% by mass or more, based on the total amount of adhesive, from the viewpoint of further reducing melt viscosity and further suppressing the occurrence of cracks and fissures on the film surface. The content of compound (Y1) may be 20% by mass or less, 15% by mass or less, or 10% by mass or less, based on the total amount of adhesive, from the viewpoint of easily suppressing excessive tackiness of the film adhesive and easily suppressing edge fusion. From these viewpoints, the content of compound (Y1) may be 1 to 20% by mass, 2 to 15% by mass or 3 to 10% by mass, based on the total amount of adhesive.
[0072] From the viewpoint of increasing toughness, the content of compound (Y2) may be 0.5% by mass or more, 1.5% by mass or more, or 2.5% by mass or more, based on the total amount of adhesive. The content of compound (Y2) may also be 0% by mass, based on the total amount of adhesive. From the viewpoint of preventing a decrease in crosslinking density and cured physical properties, the content of compound (Y2) may be 8% by mass or less, 6% by mass or less, or 4% by mass or less, based on the total amount of adhesive. From these viewpoints, the content of compound (Y2) may be 0-8% by mass, 0.5-8% by mass, 1.5-6% by mass, or 2.5-4% by mass, based on the total amount of adhesive.
[0073] The ratio of the content of compound (Y2) to the content of compound (Y1) may be 0 or more, 0.4 or more, or 0.8 or more, and may be 2.5 or less, 2.0 or less, or 1.5 or less, and may be 0 to 2.5, 0.4 to 2.0, or 0.8 to 1.5.
[0074] The content of component (A2) may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, based on the total amount of adhesive, from the viewpoint of further reducing melt viscosity and further suppressing the occurrence of cracks and fissures on the film surface. The content of component (A2) may be 20% by mass or less, 15% by mass or less, or 10% by mass or less, based on the total amount of adhesive, from the viewpoint of easily suppressing excessive increase in the tackiness of the film and easily suppressing edge fusion. From these viewpoints, the content of component (A2) may be 1 to 20% by mass, 3 to 15% by mass or 5 to 10% by mass, based on the total amount of adhesive.
[0075] The content of component (A2) may be 5% by mass or more, 10% by mass or more, or 15% by mass or more, based on the total amount of component (A), from the viewpoint of further reducing melt viscosity and further suppressing the occurrence of cracks and fissures on the film surface. The content of component (A2) may be 30% by mass or less, 25% by mass or less, or 20% by mass or less, based on the total amount of component (A), from the viewpoint of easily suppressing excessive increase in film tackiness and easily suppressing edge fusion. From these viewpoints, the content of component (A2) may be 5 to 30% by mass, 10 to 25% by mass or 15 to 20% by mass, based on the total amount of component (A).
[0076] (Component B: Hardener) (B) component can be a known curing agent known as a curing agent for thermosetting resins. (B) component also includes materials generally known as curing accelerators. Examples of (B) components include phenolic resin curing agents, acid anhydride curing agents, amine curing agents, imidazole curing agents, and phosphine curing agents. Among these, phenolic resin curing agents, acid anhydride curing agents, amine curing agents, and imidazole curing agents exhibit flux activity that suppresses the formation of oxide films at the connection site, and by using these curing agents, connection reliability can be improved. From the viewpoint of enabling rapid curing when heating is carried out at low temperatures, an imidazole curing agent may be used.
[0077] Examples of imidazole-based curing agents include 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, and 2,4-diamino-6 Examples include -[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins with imidazoles. Latent curing agents containing these in microencapsulated form can also be used. Among these, compounds having a triazine ring may be used from the viewpoint of increasing slow curing properties, improving sealing properties, and suppressing void formation.
[0078] (B) The content of component (B) may be 0.5% by mass or more, 0.7% by mass or more, or 1% by mass or more, based on the total amount of adhesive, from the viewpoint of improving curability when heated. (B) The content of component (B) may be 5% by mass or less, 3% by mass or less, or 1.5% by mass or less, based on the total amount of adhesive, from the viewpoint of improving slow curing properties. From the same viewpoint as above, the content of component (B) may be 0.5 to 5% by mass, 0.7 to 3% by mass, or 1 to 1.5% by mass, based on the total amount of adhesive.
[0079] (C) Component: Thermoplastic resin Component (C) is a polymer that softens at high temperatures and contributes to improved heat resistance and film formation.
[0080] Examples of component (C) include phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, urethane resin, and acrylic rubber. These thermoplastic resins can be used individually or as a mixture or copolymer of two or more types.
[0081] Component (C) may include at least one selected from the group consisting of phenoxy resin, polyimide resin, acrylic rubber, cyanate ester resin, and polycarbodiimide resin, from the viewpoint of easily obtaining excellent heat resistance and film formation properties. From the viewpoint of achieving the above effects more significantly, phenoxy resin, polyimide resin, and acrylic rubber are preferred, and phenoxy resin is more preferred.
[0082] The weight-average molecular weight of component (C) is, for example, 10,000 or more, and may be 20,000 or more or 30,000 or more. Such a thermoplastic resin can further improve the heat resistance and film-forming properties of the adhesive. The weight-average molecular weight of component (C) may be 1,000,000 or less, and may be 500,000 or less, from the viewpoint of easily obtaining the effect of improving heat resistance. In this specification, weight-average molecular weight means the weight-average molecular weight measured in polystyrene terms using high-performance liquid chromatography (Shimadzu Corporation, product name: C-R4A). For example, the following conditions can be used for measurement. Detector: LV4000 UV Detector (manufactured by Hitachi, Ltd., product name) Pump: L6000 Pump (manufactured by Hitachi, Ltd., product name) Columns: Gelpack GL-S300MDT-5 (2 pieces total) (Manufactured by Resonac Co., Ltd., product name) Eluent: THF / DMF=1 / 1 (volume ratio) + LiBr (0.03mol / L) + H3PO4 (0.06mol / L) Flow rate: 1mL / min
[0083] The glass transition temperature (Tg) of component (C) may be 120°C or lower, 100°C or lower, or 85°C or lower, from the viewpoint of excellent adhesion to the connecting material of the adhesive (e.g., semiconductor chip). Here, Tg refers to the Tg measured using a DSC (e.g., PerkinElmer, product name: DSC-7) under the conditions of sample amount: 10 mg, heating rate: 10°C / min, and measurement atmosphere: air.
[0084] The content of component (C) may be 5% by mass or more, 7% by mass or more, or 10% by mass or more, based on the total amount of adhesive, from the viewpoint of improving heat resistance and film formation. The content of component (C) may be 30% by mass or less, 25% by mass or less, or 20% by mass or less, based on the total amount of adhesive, from the viewpoint of optimizing the amount of fillet generated. From these viewpoints, the content of component (C) may be 5 to 30% by mass, 7 to 25% by mass or 10 to 20% by mass, based on the total amount of adhesive.
[0085] ((D) Ingredient: Filler) Component (D) is a component (filler) that acts to control viscosity, physical properties, etc. More specifically, by using component (D), it is possible to suppress void generation during connection and reduce the moisture absorption rate of the cured product.
[0086] Component (D) may be an inorganic filler (inorganic particles; hereinafter sometimes referred to as "component (D1)") or an organic filler (organic particles; hereinafter sometimes referred to as "component (D2)"), and may contain both.
[0087] (D1) Component includes insulating inorganic fillers such as glass, silica, alumina, titanium oxide, mica, and boron nitride. Among these, it is preferable to use at least one selected from the group consisting of silica, alumina, titanium oxide, and boron nitride, and it is more preferable to use silica.
[0088] Component (D2) includes, for example, resin fillers (resin particles). Examples of resin fillers include polyurethane and polyimide. Resin fillers can provide flexibility at high temperatures such as 260°C. Note that organic fillers composed of thermoplastic resins do not fall under component (C).
[0089] Component (D) may exhibit insulating properties from the viewpoint of even greater insulation reliability. The adhesive may not contain fillers (conductive fillers) containing conductive materials such as silver, solder, or carbon black.
[0090] The physical properties of component (D) can be adjusted as appropriate by surface treatment. Component (D) may be a filler that has been surface treated to improve dispersibility or adhesion. Examples of surface treatment agents include glycidyl (epoxy), amine, phenyl, phenylamino, (meth)acrylic, and vinyl compounds.
[0091] The average particle size of component (D) is, for example, 0.5 to 1.5 μm. The average particle size of component (D) may be 1.5 μm or less from the viewpoint of preventing jamming during flip-chip connection, and may be 1.0 μm or less from the viewpoint of excellent visibility (transparency). The average particle size of component (D) is the particle size at the point corresponding to 50% of the volume when the cumulative frequency distribution curve by particle size is calculated with the total volume of particles as 100%, and can be measured using a particle size distribution analyzer using laser diffraction scattering or the like.
[0092] The content of component (D) may be 25% by mass or more, 30% by mass or more, or 35% by mass or more, based on the total amount of adhesive, from the viewpoint of suppressing a decrease in heat dissipation and from the viewpoint of suppressing the generation of voids and an increase in moisture absorption rate. The content of component (D) may be 60% by mass or less, 55% by mass or less, or 50% by mass or less, based on the total amount of adhesive, from the viewpoint of suppressing the trapping of filler into the joint. From these viewpoints, the content of component (D) may be 25-60% by mass, 30-55% by mass or 35-50% by mass, based on the total amount of adhesive.
[0093] If component (D) contains component (D1) and component (D2), the content of component (D1) in the adhesive may be 60% by mass or more, 70% by mass or more, or 80% by mass or more, 98% by mass or less, 95% by mass or less, or 90% by mass or less, or 60-98% by mass, 70-95% by mass or 80-90% by mass, based on the total amount of component (D).
[0094] (Component (E): Flux compound) Component (E) is a compound having flux activity. Component (E) can be any known compound without particular limitations, as long as it reduces and removes the oxide film on the surface of solder, etc., to facilitate metal bonding.
[0095] Component (E) may contain a compound having a carboxyl group (carboxylic acid) from the viewpoint of obtaining sufficient flux activity and better connection reliability. The carboxylic acid may be a compound having one carboxyl group (monocarboxylic acid) or a compound having two or more carboxyl groups (polycarboxylic acid). Polycarboxylic acids tend to be less volatile at high temperatures during connection compared to monocarboxylic acids. Therefore, polycarboxylic acids can further suppress the generation of voids. Furthermore, among polycarboxylic acids, compounds having two carboxyl groups are superior to compounds having three or more carboxyl groups in terms of suppressing the increase in viscosity of the film-like adhesive during storage and connection work.
[0096] Component (E) may be a compound having a group represented by the following formula (1).
[0097] [ka]
[0098] In formula (1), R 1 This indicates a hydrogen atom or an electron-donating group.
[0099] R 1 The electron-donating group may be electron-donating from the viewpoint of excellent reflow resistance and even better connection reliability. Examples of electron-donating groups include alkyl groups, hydroxyl groups, amino groups, alkoxy groups, alkylamino groups, etc. The electron-donating group is preferably a group that does not react well with other components (e.g., component (A)), more preferably an alkyl group, a hydroxyl group, or an alkoxy group, and even more preferably an alkyl group.
[0100] Alkyl groups may be linear or branched, but linear is preferred. C1-C10 alkyl groups are preferred, and C1-C5 alkyl groups are more preferred. The more carbon atoms an alkyl group has, the greater its electron-donating and steric hindrance tends to be. Alkyl groups with a carbon number within the above range offer an excellent balance between electron-donating and steric hindrance.
[0101] Examples of flux compounds having two carboxyl groups include the compound represented by the following formula (2). The compound represented by the following formula (2) can further improve the reflow resistance and connection reliability of semiconductor devices.
[0102] [ka]
[0103] In formula (2), R 1 This is equivalent to equation (1). R 2 represents a hydrogen atom or an electron-donating group, and n represents 0 or an integer of 1 or more.
[0104] R 2 The electron-donating property shown is R 1 The same electron-donating groups exemplified above can be cited. 2 R 1 It may be the same as or different from R. There may be multiple Rs. 2 They may be the same or different from one another.
[0105] In equation (2), n may be 1 or greater. When n is 1 or greater, the flux compound is less likely to volatilize even at high temperatures during connection, compared to when n is 0, and the generation of voids can be further suppressed. Also, in equation (2), n may be 15 or less, 11 or less, 6 or less, or 4 or less. When n is 15 or less, even better connection reliability can be obtained.
[0106] Specific examples of the flux compounds described above include dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, and dodecanediic acid, as well as compounds in which an electron-donating group is substituted at the 2-position of these dicarboxylic acids (e.g., 2-methylglutaric acid). Among these, the flux compound having two carboxyl groups may be 2-methylglutaric acid, from the viewpoint of further improving the effect of void reduction and sealing performance when combined with components (A) and (B).
[0107] The melting point of component (E) may be 150°C or lower, 140°C or lower, or 130°C or lower. Such a component (E) readily exhibits sufficient flux activity before the curing reaction between component (A) and component (B) occurs. Therefore, by using such a component (E), a semiconductor device with even better connection reliability can be obtained. Component (E) may be solid at room temperature (e.g., 25°C). The melting point of component (E) may be 25°C or higher, or 50°C or higher. From these viewpoints, the melting point of component (E) may be 25 to 150°C, 25 to 140°C, or 50 to 130°C. In this specification, a melting point of 150°C or lower means that the upper limit of the melting point is 150°C or lower, and a melting point of 25°C or higher means that the lower limit of the melting point is 25°C or higher.
[0108] The content of component (E) may be 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more, based on the total amount of adhesive, from the viewpoint of obtaining a better flux effect. The content of component (E) may be 5% by mass or less, 3% by mass or less, or 2% by mass or less, based on the total amount of adhesive, from the viewpoint of reducing the amount of wafer warping when manufacturing semiconductor devices. From these viewpoints, the content of component (E) may be 0.1 to 5% by mass, 0.3 to 3% by mass or 0.5 to 2% by mass, based on the total amount of adhesive.
[0109] (Other additives) The film-like adhesive may further contain other additives such as antioxidants, silane coupling agents, titanium coupling agents, leveling agents, and ion trapping agents. The content of these additives can be adjusted as appropriate to ensure that the effects of each additive are realized.
[0110] <Method for manufacturing semiconductor adhesives> The semiconductor adhesive of the above embodiment is obtained by mixing component A), component B, component C, component D, and other components added as needed (component E, other additives).
[0111] When the semiconductor adhesive is in film form, the semiconductor adhesive (film-type semiconductor adhesive) can be obtained by a method that includes the step of forming an adhesive layer on a substrate (for example, a film-type substrate). When forming an adhesive layer on a substrate, for example, first, components (A), (B), (C), (D), and other components added as needed (component (E), other additives) are added to an organic solvent and dissolved or dispersed by stirring, mixing, kneading, etc. to prepare a coating solution. Then, the prepared coating solution is applied to a substrate that has been subjected to a release treatment using a knife coater, roll coater, applicator, etc. to form a coating film, and the organic solvent is reduced from the coating film by heating. This allows the adhesive layer (film-type adhesive) to be formed.
[0112] The organic solvent used in preparing the coating solution may have the property of uniformly dissolving or dispersing each component. Examples of effective solvents include dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, diethylene glycol dimethyl ether, toluene, benzene, xylene, methyl ethyl ketone, tetrahydrofuran, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, dioxane, cyclohexanone, and ethyl acetate. Stirring, mixing, and kneading during the preparation of the coating solution can be carried out using, for example, a stirrer, a sloshing machine, a three-roll mill, a ball mill, a bead mill, a homodisper, etc.
[0113] The substrate is not particularly limited as long as it has heat resistance that can withstand the heating conditions when volatilizing organic solvents. Examples of substrates include polyolefin films such as polypropylene film and polymethylpentene film; polyester films such as polyethylene terephthalate film and polyethylene naphthalate film; polyimide films; and polyetherimide films. The substrate is not limited to a single layer made of these films, but may also be a multilayer film made of two or more materials. The substrate may also be a film with a release treatment applied to its surface.
[0114] The drying conditions for volatilizing the organic solvent from the coating on the substrate may be any conditions that allow the organic solvent to volatilize sufficiently. For example, the heating temperature may be 50 to 200°C, and the heating time (holding time) may be 0.1 to 90 minutes. If there is no effect on voids or viscosity adjustment after mounting, the drying conditions may be such that the organic solvent is removed to 1.5% by mass or less based on the total amount of the film-like adhesive.
[0115] In one embodiment, for example, a semiconductor adhesive may be obtained by laminating a film-like adhesive produced by the above method with another film-like adhesive. This method yields a semiconductor adhesive (film-like adhesive) having multiple regions aligned in the thickness direction.
[0116] <Semiconductor device> Next, a semiconductor device manufactured using the semiconductor adhesive of the above embodiment will be described.
[0117] 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 chip 20 and a substrate 25 facing each other, wiring (first connection part and second connection part) 15 arranged on the opposing surfaces of the semiconductor chip 20 and the substrate 25, connection bumps 30 that connect the wiring 15 of the semiconductor chip 20 and the substrate 25 to each other, and a sealing part 40 made of cured adhesive that fills the gap between the semiconductor chip 20 and the substrate 25. The semiconductor chip 20 and the substrate 25 are flip-chip connected by the wiring 15 and the connection bumps 30. The wiring 15 and the connection bumps 30 are sealed by cured adhesive and isolated from the external environment.
[0118] The semiconductor device 200 shown in Figure 2(b) comprises a semiconductor chip 20 and a substrate 25 facing each other, bumps (first connection part and second connection part) 32 arranged on the opposing surfaces of the semiconductor chip 20 and the substrate 25, and a sealing part 40 made of a cured adhesive that fills the gap between the semiconductor chip 20 and the substrate 25. The semiconductor chip 20 and the substrate 25 are connected via a flip-chip connection by the connection of the opposing bumps 32 to each other. The bumps 32 are sealed by the sealing part 40 and isolated from the external environment.
[0119] Examples of semiconductor chips 20 include semiconductor chips made from elemental semiconductors composed of the same type of element, such as silicon and germanium, and semiconductor chips made from compound semiconductors, such as gallium arsenide and indium phosphide.
[0120] The substrate 25 is not particularly limited as long as it is used to mount the semiconductor chip 20. Examples of the substrate 25 include semiconductor chips, semiconductor wafers, wiring circuit boards, etc.
[0121] The semiconductor chip that can be used as the substrate 25 is the same as the semiconductor chip 20, and the same semiconductor chip as the semiconductor chip 20 can be used as the substrate 25.
[0122] The semiconductor wafer that can be used as the substrate 25 may, for example, have a configuration in which multiple semiconductor chips, as exemplified by the semiconductor chip 20, are linked together.
[0123] Examples of wiring circuit boards that can be used as the substrate 25 include circuit boards having wiring (wiring patterns) 15 formed by etching away unnecessary parts of a metal film on the surface of an insulating substrate mainly composed of glass epoxy, polyimide, polyester, ceramic, epoxy, bismaleimidotriazine, etc., circuit boards in which wiring 15 is formed on the surface of an insulating substrate by metal plating or the like, and circuit boards in which wiring 15 is formed by printing a conductive material on the surface of an insulating substrate.
[0124] The connection parts such as the wiring 15 and bumps 32 may contain, as a main component, gold, silver, copper, solder (main components of which may be, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, tin-silver-copper, etc.), nickel, tin, lead, etc., and may contain multiple metals.
[0125] The main metal component of the connection part may be gold, silver, or copper, from the viewpoint of obtaining a package with excellent electrical and thermal conductivity of the connection part. From the above viewpoint, silver and copper are preferred. The main metal component of the connection part may be silver, copper, or solder, which are inexpensive materials, from the viewpoint of obtaining a package with reduced costs. From the above viewpoint, copper and solder are preferred, and solder is more preferred. The main metal component of the connection part may be gold, silver, copper, or solder, from the viewpoint of suppressing the formation of an oxide film on the surface of the metal at room temperature (e.g., 25°C), as this can reduce productivity and increase costs. From the above viewpoint, gold, silver, and solder are preferred, and gold and silver are more preferred.
[0126] On the surfaces of the wiring 15 and bump 32, a metal layer may be formed, for example by plating, with gold, silver, copper, solder (main components being, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, etc.), tin, nickel, etc. as the main components. This metal layer may consist of only one component or multiple components. Furthermore, the metal layer may have a single layer or a structure in which multiple metal layers are laminated.
[0127] A semiconductor device may be a stack of multiple structures (packages) as shown in semiconductor devices 100 and 200. In this case, semiconductor devices 100 and 200 may be electrically connected to each other by bumps, wiring, etc., containing gold, silver, copper, solder (main components being, for example, tin-silver, tin-lead, tin-bismuth, tin-copper, and tin-silver-copper), tin, nickel, etc.
[0128] As a method for stacking multiple semiconductor devices, as shown in Figure 3, one example is TSV (Through-Silicon Via) technology. In the semiconductor device 500 shown in Figure 3, the semiconductor chip 20 and the interposer 50 are connected via a flip-chip connection by connecting the wiring 15 formed on the interposer 50 to the wiring 15 on the semiconductor chip 20 via connecting bumps 30. The gap between the semiconductor chip 20 and the interposer 50 is filled with a cured adhesive, forming a sealing portion 40. On the surface of the semiconductor chip 20 opposite to the interposer 50, semiconductor chips 20 are repeatedly stacked via the wiring 15, connecting bumps 30, and sealing portion 40. The wiring 15 on the pattern surfaces on the front and back of the semiconductor chip 20 are connected to each other by through-electrodes 34 filled in holes that penetrate the interior of the semiconductor chip 20. The material of the through-electrodes 34 can be copper, aluminum, etc.
[0129] Such TSV technology makes it possible to acquire signals from the back surface of semiconductor chips that are not normally used. Furthermore, because the through-electrode 34 is passed vertically through the semiconductor chip 20, the distance between opposing semiconductor chips 20 and between the semiconductor chip 20 and the interposer 50 is shortened, enabling flexible connections. The semiconductor adhesive of this embodiment can be applied as a semiconductor adhesive between opposing semiconductor chips 20 and between the semiconductor chip 20 and the interposer 50 in such TSV technology.
[0130] Furthermore, with highly flexible bump formation methods such as area bump chip technology, semiconductor chips can be directly mounted to the motherboard without the need for an interposer. The semiconductor adhesive of this embodiment can also be applied when directly mounting such semiconductor chips to the motherboard. In addition, the semiconductor adhesive of this embodiment can also be applied when sealing gaps (air spaces) between two wiring circuit boards when stacking them.
[0131] <Manufacturing method for semiconductor devices> Next, a method for manufacturing a semiconductor device using the semiconductor adhesive of the above embodiment will be described.
[0132] One embodiment of a semiconductor device manufacturing method includes, for example, a step of heating and joining a semiconductor chip and a substrate in a state where their connection portions face each other via a semiconductor adhesive.
[0133] The above process may be a process of electrically connecting the connection portion of the semiconductor chip to the connection portion of the substrate, and sealing the gap between the semiconductor chip and the substrate.
[0134] A method for manufacturing a semiconductor device may include, for example, a step of preparing an adhesive-coated semiconductor chip comprising a semiconductor chip and a layer made of the semiconductor adhesive of the above embodiment (for example, a layer made of a film-like adhesive) provided on the semiconductor chip. In this case, the adhesive-coated semiconductor chip may be placed on a substrate from the adhesive side, heated and optionally pressurized, thereby electrically connecting the connection portion of the semiconductor chip to the connection portion of the substrate and sealing the gap between the semiconductor chip and the substrate.
[0135] The method for manufacturing a semiconductor device may further include a step of applying the semiconductor adhesive of the above embodiment onto the connection surface of a semiconductor chip or its precursor (for example, a step of attaching a film-like adhesive). Here, the semiconductor chip precursor means a component that becomes a semiconductor chip through processing. A specific example of a semiconductor chip precursor is a semiconductor wafer. When a semiconductor wafer is used as the semiconductor chip precursor, the method for manufacturing a semiconductor device may further include a step of dicing the semiconductor wafer or the semiconductor wafer with adhesive.
[0136] In the method for manufacturing a semiconductor device, the adhesive tape with adhesive tape described above may be used. The adhesive tape with adhesive tape may be attached to the connection surface of a semiconductor wafer before the backgrinding process, or to the connection surface of a semiconductor wafer after the backgrinding process. That is, the method for manufacturing a semiconductor device may further include a lamination step in which the adhesive tape is attached from the semiconductor film-like adhesive side to the connection surface of a semiconductor wafer (a semiconductor wafer before or after the backgrinding process), which is a precursor of a semiconductor chip. In the latter case, the adhesive tape may be a backgrind tape, and the method for manufacturing a semiconductor device may further include a backgrinding step in addition to the lamination step in which the semiconductor wafer to which the adhesive tape is attached is ground from the side opposite to the adhesive tape. Furthermore, when using the adhesive tape with adhesive tape described above, the method for manufacturing a semiconductor device may further include a step of peeling off the adhesive tape.
[0137] The following describes in more detail the method for manufacturing a semiconductor device, using a film-like adhesive 1 and a semiconductor chip precursor (semiconductor wafer) as an example.
[0138] Figures 4, 5, 6, 7, and 8 are schematic cross-sectional views illustrating one embodiment of a semiconductor device manufacturing method. The semiconductor device manufacturing method of one embodiment includes the following steps (a) to (e). Step (a): A step to prepare a laminate 6 comprising a semiconductor wafer A having a connecting portion (first connecting portion) 5 on one main surface (connecting surface) and a film-like adhesive 1 provided on the main surface of the semiconductor wafer A (see Figure 4). Step (b): A backgrinding step in which the side of the laminate 6 opposite to the side where the film-like adhesive 1 is provided (the side opposite to the side where the connection portion 5 of the semiconductor wafer A is provided) is ground (see Figure 5). Step (c): The process of separating the laminate 6 into individual pieces to obtain a semiconductor chip 8 with a film-like adhesive having a connecting portion 5 (see Figure 6). Step (d): A step of picking up the semiconductor chip 8 with film adhesive from the side of the individualized film adhesive 1a (see Figure 7). Step (e): The semiconductor chip 8 with film adhesive is placed on the main surface (connecting surface) of a substrate 9 having a connecting portion (second connecting portion) 10 on one of its main surfaces, starting from the side with the film adhesive 1a, and heated to electrically connect the connecting portion 5 of the semiconductor chip 8 with film adhesive to the connecting portion 10 of the substrate 9, and to seal the gap between the semiconductor chip 8 with film adhesive and the substrate 9 (see Figure 8). If a semiconductor wafer with pre-adjusted thickness is used, step (b) does not need to be performed.
[0139] (Step (a)) Step (a) may be a step of preparing a pre-fabricated laminate 6, or it may be a step of manufacturing the laminate 6. The laminate 6 may be manufactured, for example, by the following method.
[0140] First, an adhesive tape is prepared, in which a base material 4 is provided on a film-like adhesive 1, and this is placed in a predetermined apparatus (see Figure 4(a)). The base material 4 is, for example, a backgrind tape. Next, a semiconductor wafer A having a connection portion 5 (wiring, bump, etc.) on one main surface is prepared, and the film-like adhesive 1 is attached to the main surface of the semiconductor wafer A (the surface on which the connection portion 5 is provided, the connection surface). This results in a laminate 6 in which the semiconductor wafer A and the film-like adhesive 1 are stacked in this order (see Figure 4(b)).
[0141] The film-like adhesive 1 can be applied by heat pressing, roll lamination, vacuum lamination, etc. The supply area and thickness of the film-like adhesive 1 are appropriately set according to the size of the semiconductor wafer and substrate, the height of the connection part, etc. In Figure 4, the thickness of the film-like adhesive 1 is greater than the height of the connection part 5 of the semiconductor wafer A, and the connection part 5 is covered with the film-like adhesive 1, but the thickness of the film-like adhesive 1 may be less than the height of the connection part 5.
[0142] (Step (b)) In step (b), for example, the semiconductor wafer A of the laminate 6 is ground using a grinder G (see Figures 5(a) and (b)). This thins the semiconductor wafer A. The thickness of the semiconductor wafer after grinding may be, for example, 10 to 300 μm. From the viewpoint of miniaturizing and thinning semiconductor devices, the thickness of the semiconductor wafer may be 20 to 100 μm.
[0143] (Process (c)) In step (c), for example, first, a dicing tape 7 is attached to the semiconductor wafer A side of the laminate 6, and this is placed in a predetermined apparatus (see Figure 6(a)). The substrate 4 may be peeled off before or after attaching the laminate 6 to the dicing tape 7. Next, the laminate 6 is diced with a dicing saw D. In this way, the laminate 6 is divided into individual pieces, and a semiconductor chip 8 with a film-like adhesive, which has a film-like adhesive 1a on the semiconductor chip A', is obtained (see Figure 6(b)). A connecting portion 5 is provided on the side of the semiconductor chip A' that has the film-like adhesive 1a.
[0144] (Step (d)) In step (d), for example, the dicing tape 7 is expanded to separate the film-adhesive semiconductor chips 8 obtained by the dicing process, and the film-adhesive semiconductor chips 8 that have been pushed up from the dicing tape 7 side by the needle N are picked up from the film-adhesive 1a side by the pick-up tool P (see Figure 7). The picked-up film-adhesive semiconductor chips 8 are then transferred to a bonding tool and used for bonding in step (e).
[0145] (Step (e)) In step (e), for example, first, a substrate 9 for mounting a semiconductor chip having a connection portion 10 (second connection portion) on one side is prepared, and the semiconductor chip 8 with film adhesive and the substrate 9 are aligned. Next, using a bonding tool, the semiconductor chip 8 with film adhesive is placed on the main surface of the substrate 9 where the connection portion 10 (wiring, bumps, etc.) is provided, from the film adhesive 1a side, and heated to bond the semiconductor chip 8 with film adhesive and the substrate 9 (see Figures 8(a) and 8(b)). As a result, the connection portion 5 of the semiconductor chip 8 with film adhesive and the connection portion 10 of the substrate 9 are electrically connected, and a sealing portion 1a' made of cured film adhesive 1a is formed between the semiconductor chip A' and the substrate 9, sealing the gap between the semiconductor chip 8 with film adhesive and the substrate 9, and a semiconductor device 11, which is a bonded body of the semiconductor chip 8 with film adhesive and the substrate 9, is obtained.
[0146] When a solder bump is used on either the connection part 5 or the connection part 10 (for example, when the connection part 5 or the connection part 10 is a wire with a solder bump), the connection part 5 and the connection part 10 are electrically and mechanically connected by soldering.
[0147] The heating in step (e) may be performed while the semiconductor chip is being placed, or after the semiconductor chip has been placed. The heating and placement in step (e) may be performed by thermocompression bonding. Step (e) may include a step of temporarily fixing the semiconductor chip after alignment (temporary fixing step) and a step of joining the semiconductor chip A' and the substrate 9 and sealing the connection by melting the bumps (e.g., solder bumps) provided at the connection by heat treatment (sealing step). Since it is not necessarily required to form a metal bond at the temporary fixing stage, the temporary fixing step can be carried out with low load, short time, and low temperature. Therefore, when the temporary fixing step and the sealing step are carried out in step (e), productivity can be improved and deterioration of the connection can be suppressed.
[0148] The load applied for temporary fixing is set appropriately, taking into consideration the number of connection points (bumps), the absorption of variations in the height of the connection points (bumps), and the amount of deformation of the connection points (bumps). From the viewpoint of eliminating voids and facilitating contact between the connection points, the load may be, for example, 0.009 to 0.2 N per connection point (e.g., bump).
[0149] Heating during the sealing process may be performed using equipment capable of heating above the melting point of the metal at the connection point. The heating temperature may be the temperature at which the film adhesive begins to harden, or it may be the temperature at which it hardens completely. The heating temperature and heating time can be set as appropriate.
[0150] The heating time in the sealing process varies depending on the type of metal that makes up the connection, but it may be short from the viewpoint of improving productivity. When solder bumps are used in the connection, the heating time may be 20 seconds or less, 10 seconds or less, or 5 seconds or less. In the case of copper-copper or copper-gold metal connections, the connection time may be 60 seconds or less.
[0151] In the sealing process, heating and pressurization may be performed simultaneously using a device capable of both heating and pressurization. That is, heating in the sealing process may be done by thermocompression bonding. In this case, the load (connecting load) is set considering the size of the connecting members, the number of connection points, variations in height, the amount of deformation of the connection points due to pressurization, etc. The connecting load may be, for example, above atmospheric pressure and 1 MPa or less. From the viewpoint of void suppression and improved connectability, the load may be 0.05 to 0.5 MPa. The crimping time (connecting time) varies depending on the type of metal constituting the connection point, but from the viewpoint of improving productivity, it may be short. If the connection point is a solder bump, the crimping time may be 20 seconds or less, 10 seconds or less, or 5 seconds or less. Note that with direct pressurization using a crimping machine, the heat from the crimping machine is not easily transferred to the fillet. Therefore, from the viewpoint of sufficiently hardening the fillet, pressurization by air pressure may be used. From the viewpoint of batch sealing, pressurization during heating may also be pressurization by air pressure (pressurization by a pressurized reflow oven, pressurized oven, etc.).
[0152] After connecting the semiconductor chip A' and the substrate 9, the connection reliability may be further improved by performing a heat treatment in an oven or the like. [Examples]
[0153] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.
[0154] Details of the materials used in the examples and comparative examples are as follows.
[0155] <(A) Component: Thermosetting resin> [(A1) Ingredients: Epoxy resin that is solid at 30°C] • (A1-1): Polyfunctional solid epoxy resin containing the dicyclopentadiene structure described in Table 1 (manufactured by DIC Corporation, product name: HP-7200L, epoxy equivalent: 230-260 g / eq, softening point: 50-60°C, ICI viscosity at 150°C: 0.01-0.1 Pa·s) • (A1-2): Polyfunctional solid epoxy resin containing the dicyclopentadiene structure described in Table 1 (manufactured by DIC Corporation, product name: HP-7200, epoxy equivalent: 250-280 g / eq, softening point: 57-68°C, ICI viscosity at 150°C: 0.01-0.2 Pa·s) • (A1-3): Polyfunctional solid epoxy resin containing the dicyclopentadiene structure described in Table 1 (manufactured by DIC Corporation, product name: HP-7200H, epoxy equivalent: 265-300 g / eq, softening point: 75-90°C, ICI viscosity at 150°C: 0.2-0.6 Pa·s) • (A1-4): Polyfunctional solid epoxy resin containing the biphenylene structure described in Table 1 (Nippon Kayaku Co., Ltd., product name: NC-3000L, epoxy equivalent: 272 g / eq, softening point: 52°C, ICI viscosity at 150°C: 0.03 Pa·s) • (A1-5): Polyfunctional solid epoxy resin containing the naphthalene structure listed in Table 1 (Nippon Kayaku Co., Ltd., product name: NC-7000L, epoxy equivalent: 232 g / eq, softening point: 90°C, ICI viscosity at 150°C: 0.78 Pa·s) • (A1-6): Polyfunctional solid epoxy resin containing the triphenolmethane structure described in Table 1 (manufactured by Mitsubishi Chemical Corporation, product name: jER1032H60, "jER" is a registered trademark (hereinafter the same), epoxy equivalent: 169 g / eq, softening point: 62°C, ICI viscosity at 150°C: 0.2 Pa·s) (A1-7): Cresol novolac type epoxy resin (manufactured by DIC Corporation, product name: Epiclon N-660, "Epiclon" is a registered trademark), epoxy equivalent: 200-215 g / eq, softening point: 61-69°C, ICI viscosity at 150°C: 0.1-0.3 Pa·s) [(A2) Ingredients: Epoxy resin that is liquid at 30°C] • (A2-1): Bisphenol F type liquid epoxy resin as listed in Table 1 (manufactured by Mitsubishi Chemical Corporation, product name: jERYL983U, epoxy equivalent: 165~175g / eq) • (A2-2): Flexible epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jERYX7110B80, epoxy equivalent: 950~1250g / eq)
[0156] [Table 1] In the table, n represents the number of repetitions (integer) of the structure within the parentheses. However, n is not necessarily the same for each expression.
[0157] <(B) Component: Hardener> • (B-1): 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanurate adduct (manufactured by Shikoku Chemicals Co., Ltd., product name: 2MAOK-PW)
[0158] <(C) Component: Thermoplastic resin> • (C-1): Phenoxy resin (Phenoxy resin, manufactured by Nippon Steel Chemical & Material Co., Ltd., product name: ZX-1356-2, Tg: approx. 71℃, weight-average molecular weight Mw: approx. 63000)
[0159] <(D) Ingredient: Filler> [(D1) Ingredient: Inorganic filler] • (D1-1): Silica filler (manufactured by Admatex Co., Ltd., product name: KE180G-HLA) [(D2) Ingredients: Organic filler] • (D2-1): Core-shell type organic microparticles (manufactured by Rohm & Haas Japan Co., Ltd., product name: EXL-2655)
[0160] <(E) Component: Flux compound> • (E-1): 2-Methylglutaric acid (manufactured by Aldrich, melting point: approximately 78°C)
[0161] <Examples 1-5 and Comparative Examples 1-3> (Preparation of film-like adhesive) The components shown in Table 2 were added to an organic solvent (cyclohexanone) so that the NV value ([mass of paint after drying] / [mass of paint before drying] × 100) was 42%, and a mixture was obtained. The amount of each component added was as shown in Table 2 (unit: parts by mass). Then, Φ1.0 mm beads were added to the mixture and stirred for 1 hour using a bead mill (Fritsch Japan Co., Ltd., planetary type fine grinder P-7). The amount of beads added was the same as the mass of the mixture. After stirring, the beads were removed by filtration to obtain coating solutions 1 to 8.
[0162] Using the obtained coating solutions 1 to 8, film-like adhesives for Examples 1 to 5 and Comparative Examples 1 to 3 were prepared. Specifically, first, the coating solution was applied to a base film (Toyobo Co., Ltd., product name "Purex A31B0") using a small precision coating device (Ken'i Seiki) so that the film thickness after drying would be 5 μm. Next, the coating film was dried in a clean oven (ESPEC) (100°C / 5 min) to obtain the film-like adhesives for Examples 1 to 5 and Comparative Examples 1 to 3, respectively.
[0163] <Rating> (Viscosity measurement and DSC measurement) [Sample preparation] Using the 5 μm thick film-like adhesives (initial samples) obtained in the examples and comparative examples, 400 μm thick measurement samples were prepared. For viscosity measurement samples, a 400 μm thick laminate was obtained by laminating the initial samples multiple times using a desktop laminator (product name: Hotdog GK-13DX, manufactured by Lamy Corporation), and then punching out the laminate using a Φ10 mm punch. For DSC measurement samples, the laminate prepared in the same manner as above was punched out using a Φ5.0 mm punch. The lamination of the initial samples was carried out under the conditions of a device setting temperature of 60°C and device transport speed level 3.
[0164] [Viscosity measurement] For the sample used for measurement, the melt viscosity at 80°C (80°C viscosity), the minimum melt viscosity, and the temperature at which the minimum melt viscosity is observed (melting temperature) were measured using a rotary rheometer (TA Instruments, product name: ARES). The measurement conditions were as follows. [Measurement conditions] • Measuring tool size: 8mmφ • Heating rate: 10°C / min • Frequency: 10Hz Temperature range: 30~165℃
[0165] [DSC measurement] The sample for measurement was weighed on an aluminum pan (manufactured by Epollead Service Co., Ltd.), covered with an aluminum lid, and sealed inside the sample pan using a crimper. A differential scanning calorimeter (Thermo plus DSC8235E, manufactured by Rigaku Corporation) was used to measure under a nitrogen atmosphere at a heating rate of 10°C / min and a measurement temperature range of 30 to 300°C. Using a partial area analysis method, the total calorific value (DSC calorific value) [unit: J / g] of the exothermic peaks in the DSC curve was calculated by specifying the baseline of the analysis temperature range and integrating the peak area by instructing the analysis within the temperature range of 110°C to 220°C for each DSC curve. In addition, the peak top temperature (DSC peak temperature) of the exothermic peaks in the DSC curve was determined by instructing the analysis within the temperature range of 110°C to 220°C for each DSC curve.
[0166] (Measuring fillet volume) [Creating connection structures] Using the 5 μm thick film-like adhesives (initial samples) obtained in the examples and comparative examples, evaluation samples with a thickness of 10 μm were prepared. The evaluation samples were obtained by laminating the initial samples once using a desktop laminator (product name: Hotdog GK-13DX, manufactured by Lamy Corporation). Next, the evaluation sample was attached to a mirror chip (chip size: 8 inches, thickness: 100 μm, product name: 8” mirror wafer DP100, Nichiwa Kogyo Co., Ltd.) at 80°C, and then diced to 7.3 mm × 7.3 mm using a dicer (product name: DFD6361, manufactured by Disco Corporation). The semiconductor chip with the film adhesive attached was then sequentially pressed and temporarily fixed to another semiconductor chip (chip size: 12 mm × 12 mm, thickness: 150 μm, product name: 8” mirror wafer DP150, manufactured by Apollo Engineering Co., Ltd.) by heating and pressurizing with a flip-chip bonder (LFB-2301, manufactured by Shinkawa Co., Ltd.). The stage temperature during temporary fixing was 70°C, and the pressing conditions were tool temperature: 120°C, load: 60 N, time: 3 seconds, to produce a laminate (temporarily fixed body) after temporary pressing.
[0167] The laminated body (temporarily fixed body) after the above temporary crimping was subjected to high-temperature crimping using a flip-chip bonder (LFB-2301, manufactured by Shinkawa Co., Ltd.). The stage temperature during high-temperature crimping was set to 70°C, and the crimping conditions were tool temperature: 260°C, load: 60N, and time: 1 second and 3 seconds to obtain a connecting structure (high-temperature crimped laminated body).
[0168] [Measuring fillet volume] The connection structure (high-temperature crimped laminate) obtained above was observed from the semiconductor chip side using a digital microscope VHX-6000 (manufactured by Keyence), and the length of the adhesive (fillet) protruding from the four sides of the semiconductor chip was measured. For each side, the maximum value of the shortest distance from the end of the protruding adhesive to the semiconductor chip was adopted as the fillet length. The fillet amount was the average value of the fillet lengths measured on each of the four sides. The ratio of the fillet amount F3 when the crimping time was 3 seconds to the fillet amount F1 when the crimping time was 1 second (F3 / F1) was calculated.
[0169] [Table 2]
[0170] The adhesives of Examples 1 to 5 had a minimum melt viscosity of less than 2000 Pa·s, confirming that they possessed a sufficiently low minimum melt viscosity. Furthermore, the adhesives of Examples 1 to 5 had a fillet ratio (F3 / F1) of 1.35 or higher, confirming that they possessed sufficient slow curing properties. On the other hand, the adhesives of Comparative Examples 1 to 2, which did not contain compound (X) (a compound having a structure in which two or more rings selected from aliphatic and aromatic rings are directly bonded, and a monocyclic aromatic ring in which at least one hydrogen atom is substituted with a glycidyloxy group), had a fillet ratio (F3 / F1) of less than 1.35, confirming that they did not possess sufficient slow curing properties. [Explanation of Symbols]
[0171] 1,1a...Semiconductor adhesive (film adhesive), 4...Substrate, 5...Connecting part (first connecting part), 9...Base, 10...Connecting part (second connecting part), 11...Semiconductor device, 15...Wiring (first and second connecting parts), 20...Semiconductor chip, 25...Base, 30...Connecting bump, 32...Bump (first and second connecting parts), 40...Sealing part, 100,200,500...Semiconductor device, A...Semiconductor wafer, A'...Semiconductor chip.
Claims
1. It contains a thermosetting resin, a curing agent, a thermoplastic resin, and a filler. The thermosetting resin comprises an epoxy resin that is solid at 30°C and an epoxy resin that is liquid at 30°C. A semiconductor adhesive comprising an epoxy resin that is solid at 30°C, having a structure in which two or more rings selected from aliphatic rings and aromatic rings are directly bonded, and a compound having a monocyclic aromatic ring in which at least one hydrogen atom is substituted with a glycidyloxy group.
2. The semiconductor adhesive according to claim 1, wherein the compound has at least one structure selected from the group consisting of a dicyclopentadiene structure, a naphthalene structure, and a biphenyl structure.
3. The semiconductor adhesive according to claim 1, wherein the epoxy resin that is solid at 30°C contains at least one compound represented by the following formulas (1-1) to (1-2). 【Chemistry 1】 [In formula (1-1), X represents a divalent group including a structure in which two or more rings selected from aliphatic and aromatic rings are directly bonded, L represents a single bond or a methylene group, R 1 represents an alkyl group having 1 to 4 carbon atoms, n1 represents an integer from 1 to 10, and m represents an integer from 0 to 3. Multiple X's may be the same or different from each other, multiple L's may be the same or different from each other, and multiple R's may be the same or different from each other. 1 The elements may be identical or different from each other, and multiple instances of m may be identical or different from each other. 【Chemistry 2】 [In formula (1-2), X, L, R 1 And m are the same as above, and n² represents an integer from 1 to 10. Multiple X may be the same or different from each other, multiple L may be the same or different from each other, and multiple R 1 The elements may be identical or different from each other, and multiple instances of m may be identical or different from each other.
4. The semiconductor adhesive according to claim 1, wherein the epoxy resin that is liquid at 30°C contains a compound represented by the following formula (2-1). 【Transformation 3】 [In formula (2-1), R 11 R represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 12 represents a glycidyl group, p represents an integer from 0 to 4, and q represents an integer greater than or equal to 0. Multiple R 11 These may be the same or different from each other, and there may be multiple R 12 The elements p may be identical or different from each other, the multiple p elements may be identical or different from each other, and the multiple q elements may be identical or different from each other.
5. The semiconductor adhesive according to claim 1, wherein the content of the epoxy resin that is solid at 30°C is 30 to 42% by mass, based on the total mass of the semiconductor adhesive.
6. The semiconductor adhesive according to claim 1, wherein the content of the epoxy resin that is liquid at 30°C is 1 to 20% by mass, based on the total mass of the semiconductor adhesive.
7. The semiconductor adhesive according to claim 1, wherein the curing agent comprises an imidazole-based curing agent.
8. The semiconductor adhesive according to claim 1, wherein the content of the curing agent is 0.5 to 5% by mass, based on the total mass of the semiconductor adhesive.
9. The semiconductor adhesive according to claim 1, wherein the thermoplastic resin comprises a phenoxy resin.
10. The semiconductor adhesive according to claim 1, wherein the filler contains silica.
11. The semiconductor adhesive according to claim 1, further containing a flux compound.
12. The semiconductor adhesive according to claim 11, wherein the flux compound comprises a carboxylic acid.
13. The semiconductor adhesive according to claim 1, wherein the melt viscosity at 80°C is less than 20,000 Pa·s.
14. The semiconductor adhesive according to claim 1, which is non-conductive.
15. A semiconductor adhesive according to claim 1, used for joining a semiconductor chip to a substrate and for sealing the gap between the semiconductor chip and the substrate.
16. A semiconductor adhesive according to any one of claims 1 to 15, which is in the form of a film.
17. A film-like adhesive comprising the semiconductor adhesive described in claim 16, An adhesive tape comprising an adhesive tape provided on the aforementioned film-like adhesive.
18. A method for manufacturing a semiconductor device, comprising the step of heating and joining a semiconductor chip and a substrate in a state where their connection portions face each other via a semiconductor adhesive described in any one of claims 1 to 15.
19. The device comprises a semiconductor chip 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 chip and the substrate and fills the gap between the semiconductor chip and the substrate. A semiconductor device wherein the sealing portion is a cured product of a semiconductor adhesive according to any one of claims 1 to 15.