Thermosetting resin film for forming semiconductor rerouting layer, semiconductor device using the same, and method for manufacturing semiconductor device

Abstract

To provide a thermosetting resin film for forming a semiconductor rerouting layer which has superior dielectric properties, excels in workability, exhibits high adhesion to copper, and is less susceptible to the influence of moisture absorption.SOLUTION: A thermosetting resin film for forming a semiconductor rerouting layer contains: (A) a maleimide compound including at least one hydrocarbon group derived from a dimer acid skeleton per molecule; and (B) at least one catalyst selected from a thermal radical polymerization initiator or an anionic polymerization initiator, with at least one of the component (A) being solid at 25°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a thermosetting resin film for forming a semiconductor redistribution layer, a semiconductor device using the same, and a method for manufacturing a semiconductor device.

Background Art

[0002] There are various methods for semiconductor packages in semiconductor devices. For example, there is a packaging method in which a semiconductor chip is covered with a sealing material, and a redistribution layer electrically connected to the semiconductor chip is further formed. Among semiconductor package methods, in recent years, a semiconductor package method called Fan-Out has been widely used from the viewpoints of high-speed transmission and thinning of the package height.

[0003] This redistribution layer is formed of copper and an insulating layer, and generally polyimide or polybenzoxazole is often used (Patent Documents 1 and 2). These materials are excellent in heat resistance, insulation properties, film physical properties, etc., and are mainly used for those that are photocurable and alkali-developable particularly in the application of forming a redistribution layer.

[0004] However, there is also a limit to suppressing transmission loss in package design, and improvement in terms of materials is expected. When the relative permittivity and dielectric tangent of the insulating material used for wiring formation are high, dielectric loss increases, and transmission loss increases as a total. In particular, polyimide widely used in these applications has an imide group itself as a polar functional group, and furthermore, a photosensitive polyimide precursor composition contains many polar compounds such as a photopolymerization initiator and a crosslinking agent. Therefore, the cured product of the composition containing polyimide has high values of relative permittivity and dielectric tangent, and a decrease in the relative permittivity and dielectric tangent of the material for forming the redistribution layer is required. Although polyimide materials for improving these problems have been proposed, they are still insufficient (Patent Document 3).

[0005] In addition, as materials for forming the rewiring layer, maleimide resin compositions mainly composed of aromatic maleimide compounds, aliphatic maleimide compounds having a substantially dimer diamine skeleton (special maleimide compounds), etc., with thermosetting and / or photocuring properties have been reported (Patent Documents 4 to 9). However, many aromatic maleimide compounds lack transparency, and photocuring is not practical. In addition, although special maleimide compounds have transparency and are excellent in photocurability, an organic solvent is essential in the development process. In addition, since the color tone of the special maleimide compound is yellow to yellowish brown, it may absorb short wavelengths. Therefore, the resolution is insufficient and scum is often generated, which is still not practical enough.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Summary of the Invention

Problems to be Solved by the Invention

[0007] On the one hand, as a semiconductor packaging method, there are methods such as forming a copper pillar first, then forming an insulating layer with a thermosetting resin, polishing to expose the head of the copper pillar, and then forming the next layer, or forming an insulating layer with a thermosetting resin first, forming vias with a laser, and forming the next layer after plating. The thermosetting resins used in these processes have a low dielectric constant and a low dielectric tangent, which are still difficult to achieve with photocurable resins, are excellent in processability, and have high adhesiveness to copper. Furthermore, according to these processes, there is a high possibility of developing a thermosetting resin with little influence of moisture absorption, which is a problem of polyimide materials, as a material for forming a redistribution layer, and the appearance of such a material has been desired. Therefore, an object of the present invention is to provide a thermosetting resin film for forming a semiconductor redistribution layer that has dielectric properties such as a low dielectric constant and a low dielectric tangent that have not yet been achieved with photocurable resins, is excellent in processability, has high adhesion to copper, and is less affected by moisture absorption. Another object is to provide a semiconductor device using the thermosetting resin film and a method for manufacturing the semiconductor device.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the present inventors have found that the following thermosetting resin composition can achieve the above object, and have completed the present invention. [1] (A) A maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule and (B) A catalyst selected from one or more of a thermal radical polymerization initiator or an anionic polymerization initiator containing The component (A) is one or more selected from any of the following formula (1), formula (2), and formula (3), and one or more of these are solids at 25°C, a thermosetting resin film for forming a semiconductor redistribution layer.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Effects of the Invention

[0009] The thermosetting resin film for forming a semiconductor redistribution layer of the present invention has dielectric properties such as a low relative permittivity and a low dielectric tangent that have not yet been achieved with photocurable resins, is excellent in processability, has high adhesion to copper, and is less affected by moisture absorption. Therefore, the resin film of the present invention is useful for forming a semiconductor redistribution layer.

Modes for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in more detail.

[0011] (A) A maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule The component (A) of the present invention is a maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule. The hydrocarbon group derived from a dimer acid skeleton is effective for exhibiting excellent dielectric properties.

[0012] Here, the dimer acid is a liquid dibasic acid mainly composed of a dicarboxylic acid having 36 carbon atoms, which is produced by dimerization of an unsaturated fatty acid having 18 carbon atoms using natural products such as vegetable oils as raw materials. The dimer acid does not have a single skeleton but has a plurality of structures, and there are several isomers. Representative dimer acids are classified by the names of linear type (a), monocyclic type (b), aromatic ring type (c), and polycyclic type (d). In this specification, the dimer acid skeleton refers to a group derived from a dimerdiamine having a structure in which the carboxy group of such a dimer acid is substituted with a primary aminomethyl group. That is, as the dimer acid skeleton, the component (A) preferably has a group in which two carboxy groups are substituted with a methylene group in each of the dimer acids represented by the following (a) to (d). Further, from the viewpoint of the heat resistance and reliability of the cured product, it is more preferable that the hydrocarbon group derived from the dimer acid skeleton in the maleimide compound of the component (A) has a structure in which the carbon-carbon double bond in the hydrocarbon group derived from the dimer acid skeleton is reduced by a hydrogenation reaction.

[0013]

Chemical formula

[0014] Specific structures of the component (A) include the following formula (1), the following formula (2), and the following formula (3). Among them, the thermosetting resin film for forming a semiconductor rewiring layer of the present invention is one or more selected from any of the following formula (1), the following formula (2), and the following formula (3), and one or more of these are solid at 25°C.

Chemical formula

Chemical formula

Chemical formula

[0015] First, although the maleimide compound represented by the formula (1) has a high melt viscosity before curing, it has better dielectric properties than maleimide compounds containing a large number of general aromatic groups. Moreover, it has a high adhesion to metal foils such as copper foils, has a lower moisture absorption amount than general thermosetting resins such as epoxy resins, and is less affected by moisture. Also, it has a higher Tg than the maleimide compound represented by the formula (2) described later, has a small coefficient of thermal expansion (CTE), and forms a highly reliable composition.

[0016] Further, in the formula (1), A independently represents a tetravalent organic group having a cyclic structure, and among them, it is preferably any of the tetravalent organic groups represented by the following formula.

Chemical formula

[0017] Further, in the formula (1), D independently represents a divalent hydrocarbon group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, more preferably 10 to 50 carbon atoms. Among them, it is preferably a branched divalent hydrocarbon group in which one or more hydrogen atoms in the divalent hydrocarbon group are substituted with an alkyl group or an alkenyl group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, more preferably 10 to 50 carbon atoms. The branched divalent hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated hydrocarbon group, and may have an alicyclic structure or an aromatic ring structure in the middle of the molecular chain. Specific examples of the branched divalent hydrocarbon group include divalent hydrocarbon groups derived from diamines with both ends called dimer diamines. Note that dimer diamines are compounds derived from dimers (dimer acids) of unsaturated fatty acids such as oleic acid. Therefore, as D, among the dimer acids represented by the above (a) to (d), groups in which two carboxy groups are each substituted with a methylene group are particularly preferred, and one or more in one molecule have a skeleton derived from this dimer acid.

[0018] In the formula (1), B is independently a divalent hydrocarbon group having 6 to 60 carbon atoms, preferably a divalent aliphatic hydrocarbon group or a hydrocarbon group having an aromatic ring, more preferably a divalent aliphatic hydrocarbon group having 6 to 30 carbon atoms or a hydrocarbon group having an aromatic ring.

[0019] In the formula (1), a is 1 to 100, preferably 1 to 60, more preferably 2 to 50. b is 1 to 200, preferably 1 to 50, more preferably 3 to 40. In particular, from the viewpoints of the film property, moldability, strength, etc. of the composition, the range of a + b being in the range of 3 to 40 is preferable. On the other hand, if a or b is too large, the fluidity may decrease and the moldability may be inferior. The order of each repeating unit enclosed by a and b is not limited, and the bonding mode may be alternating, block, or random. Among them, the block is more preferable from the viewpoint of being easily capable of increasing the Tg.

[0020] Next, when the maleimide compound represented by the formula (2) is used, it has superior dielectric properties compared to other maleimide compounds containing a large number of other general aromatics. In particular, it is not only effective in maintaining the dielectric properties even at high frequencies, but also has a stronger adhesion to the copper foil than the maleimide compound represented by the formula (1), resulting in an excellent composition.

[0021] In the formula (2), A is the same as A in the formula (1), independently represents a tetravalent organic group having a cyclic structure, and the preferred ones are the same.

[0022] In the formula (2), D is the same as D in the formula (1), and is independently a divalent hydrocarbon group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, more preferably 10 to 50 carbon atoms. Similarly, it is preferable that one or more of the hydrogen atoms in the divalent hydrocarbon group are a branched divalent hydrocarbon group substituted with an alkyl group or an alkenyl group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, more preferably 10 to 50 carbon atoms. The branched divalent hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated hydrocarbon group, and may have an alicyclic structure or an aromatic ring structure in the middle of the molecular chain. Similarly, specific examples of the branched divalent hydrocarbon group include a divalent hydrocarbon group derived from a diamine having both ends called a dimer diamine. The dimer diamine is a compound derived from a dimer (dimer acid) of an unsaturated fatty acid such as oleic acid. Therefore, as D, a group in which two carboxy groups are each substituted with a methylene group in each of the dimer acids represented by the above (a) to (d) is particularly preferable, and one or more in one molecule have a skeleton derived from this dimer acid.

[0023] In the formula (2), c is from 1 to 100, preferably from 1 to 60, more preferably from 1 to 50. If c is too large, the solubility and fluidity may decrease, and the moldability may be inferior.

[0024] Next, when the maleimide compound represented by this formula (3) is used, the dielectric properties are superior to those of other maleimide compounds containing a large number of other general aromatics. In particular, it is effective in maintaining the dielectric properties even at high frequencies. Furthermore, since it is liquid at 25°C, it has the effect of improving the moldability of the resin composition or improving the handling properties such as the film properties before curing. Therefore, when using the maleimide compound represented by this formula (3), one or more maleimide compounds that are solid at 25°C among the maleimide compounds represented by the formula (1) and the maleimide compounds represented by the formula (2) are used in combination.

[0025] The viscosity of the maleimide compound represented by formula (3) is preferably in the range of 1.0 to 5.0 Pa s as measured at 25°C and 5 rpm using a cone-and-plate rotational viscometer in accordance with JIS Z 8803:2011.

[0026] There are no particular restrictions on the number average molecular weight of the maleimide compound of component (A), but from the standpoint of ease of handling the composition, it is preferably 1,500 to 50,000, and more preferably 2,000 to 30,000. The number average molecular weight referred to in the present invention refers to the number average molecular weight measured by gel permeation chromatography (GPC) under the following conditions using polystyrene as a standard substance.

[0027] [Measurement conditions] Developing solvent: tetrahydrofuran (THF) Flow rate: 0.35mL / min Detector: Refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperHZ4000(4.6mmI.D.×15cm×1) TSKgel SuperHZ3000(4.6mmI.D.×15cm×1) TSKgel SuperHZ2000 (4.6mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 5 μL (0.2% by mass THF solution)

[0028] The component (A) may be used alone or in combination of two or more types. When a maleimide compound represented by formula (3) is used, it is used in combination with one or more maleimide compounds that are solid at 25°C and are selected from the group consisting of the maleimide compound represented by formula (1) and the maleimide compound represented by formula (2). Furthermore, the proportion of the maleimide compound that is solid at 25°C in component (A) is preferably 50 to 100 mass %, more preferably 60 to 100 mass %, and even more preferably 70 to 100 mass %. The content of the component (A) in the composition is preferably 30 to 99 mass %, more preferably 40 to 99 mass %, and even more preferably 45 to 98 mass %.

[0029] (B) a catalyst selected from the group consisting of a thermal radical polymerization initiator and an anionic polymerization initiator; Component (B) is a catalyst for accelerating the curing reaction of the thermosetting resin film of the present invention. It is added to initiate and accelerate the crosslinking reaction of the maleimide compound (component (A)) and the reaction between the maleimide group in component (A) and a reactive group that can react with the maleimide group. The catalyst is selected from the group consisting of thermal radical polymerization initiators and anionic polymerization initiators.

[0030] A thermal radical polymerization initiator is preferred when it is desired to promote the reaction of the component (A) alone, or when the reactive group that can react with a maleimide group that is contained in a thermosetting resin other than the component (A) described below is a group having a carbon-carbon double bond, such as a maleimide group, an alkenyl group, or a (meth)acrylic group.

[0031] Examples of thermal radical polymerization initiators include azo compounds, organic peroxides, and sulfates, with organic peroxides being preferred. Organic peroxides are classified into types such as allyl peroxide, dialkyl peroxide, peroxide carbonate, and hydroperoxide, but are not particularly limited. Specific examples include dicumyl peroxide, t-butyl peroxybenzoate, t-amyl peroxybenzoate, dibenzoyl peroxide, diuraroyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,1-di(t-butylperoxy)cyclohexane, di-t-butyl peroxide, and dibenzoyl peroxide.

[0032] In addition, when the reactive group of the thermosetting resin other than the component (A) that can react with the maleimide group is an epoxy group, a hydroxyl group, or an acid anhydride group, basic compounds such as imidazoles and tertiary amines, and organophosphorus compounds are preferred. Although it is possible to use imidazoles or amines for the homopolymerization of maleimide groups, caution is required as imidazoles and phosphorus compounds require very high temperatures, and amines tend to have a very short pot life.

[0033] In particular, when the thermosetting resin other than the component (A) is an epoxy resin in which the component (C) described later has two or more epoxy groups in one molecule, the component (B) acts as an anionic polymerization catalyst. Examples of the anionic polymerization catalyst include basic compounds such as imidazoles and tertiary amines as described above, and organophosphorus compounds, and imidazoles are particularly preferably used.

[0034] The component (B) is preferably blended in an amount of 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the component (A). When other thermosetting resins described later are blended in the composition, it is preferably blended in the range of 0.05 to 10 parts by mass, particularly 0.1 to 5 parts by mass, based on 100 parts by mass of the total of the component (A) and other thermosetting resin components. If it is outside the above range, during the molding of the thermosetting resin film of the present invention, curing may become extremely slow or fast, which is not preferable. In addition, the balance between the heat resistance and moisture resistance of the obtained cured product may also deteriorate. The catalyst of the component (B) may be used alone or in combination of two or more.

[0035] Other Additives In the thermosetting resin film of the present invention, various additives can be further blended as necessary within a range that does not impair the effects of the present invention. Other additives are exemplified below.

[0036] Epoxy Resin Having Two or More Epoxy Groups in One Molecule of (C) When using an anionic polymerization catalyst as the (B) component, an epoxy resin having two or more epoxy groups in one molecule can be used as the (C) component in the thermosetting resin film of the present invention. The epoxy groups in the epoxy resin react with the anionic polymerization catalyst in the aforementioned (B) component, generate active species, and then react with the maleimide groups in the (A) component to initiate anionic polymerization.

[0037] As the (C) component, considering reactivity with the (B) component and the like, an epoxy resin having a glycidyl group is preferably used.

[0038] Examples of the (C) component include phenol novolak type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenol type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, naphthol type epoxy resin, xylylene type epoxy resin, biphenyl type epoxy resin, biphenyl aralkyl type epoxy resin, triphenylmethane type epoxy resin, alicyclic type epoxy resin, glycidylamine type epoxy resin, dicyclopentadiene type epoxy resin, stilbene type epoxy resin, sulfur atom-containing epoxy resin, phosphorus atom-containing epoxy resin, and the like. When using a (C) component that is liquid at room temperature (25 °C), it is preferable from the viewpoints of compatibility and wettability with the base material.

[0039] As the blending amount of the (C) component, it is preferably blended in an amount of 0.05 to 25 parts by mass, more preferably 0.1 to 2 parts by mass, based on 100 parts by mass in total of the thermosetting resin containing the (A) component. If outside the above range, the curing may become extremely slow or fast during molding, which is not preferable. Also, the balance between the heat resistance and moisture resistance of the obtained cured product may deteriorate. When the blending amount is large, it is difficult to obtain the desired low dielectric characteristics. In addition, the epoxy resin of the (C) component may be used alone or in combination of two or more.

[0040] (D) Inorganic filler In the present invention, an inorganic filler may further be added as the component (D). The inorganic filler is blended for the purpose of increasing the strength and rigidity of the cured product of the thermosetting resin film for semiconductor rewiring layer formation of the present invention, or adjusting the coefficient of thermal expansion and the dimensional stability of the cured product. As the inorganic filler, those usually blended in an epoxy resin composition or a silicone resin composition can be used, but silica particles such as spherical silica, fused silica, and crystalline silica, and boron nitride are preferable in order not to increase the relative dielectric constant of the whole composition. Inorganic particles such as alumina, talc, magnesium hydroxide, and zinc oxide are not preferable in many cases because they have a high relative dielectric constant although they have a low dielectric loss tangent, or they have both a high dielectric loss tangent and a high relative dielectric constant.

[0041] The average particle diameter and shape of the inorganic filler are not particularly limited, but spherical silica having an average particle diameter of 0.5 to 5 μm is preferably used particularly when forming a film or a substrate. The average particle diameter is a value obtained as the mass average value D 50 (or median diameter) by measuring the particle size distribution by the laser light diffraction method.

[0042] Furthermore, the inorganic filler is preferably surface-treated with a silane coupling agent having an organic group capable of reacting with a maleimide group in order to improve the properties. Examples of such a silane coupling agent include epoxy group-containing alkoxysilane, amino group-containing alkoxysilane, (meth)acrylic group-containing alkoxysilane, and alkenyl group-containing alkoxysilane. As the silane coupling agent, (meth)acrylic group and / or amino group-containing alkoxysilane is preferably used, and specifically, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, etc. can be mentioned.

[0043] The inorganic filler may be used alone or in combination of two or more. The amount of inorganic filler added is 30 to 500 parts by mass, preferably 40 to 400 parts by mass, per 100 parts by mass of component (A).

[0044] Thermosetting resin having a reactive group capable of reacting with a maleimide group In the present invention, a thermosetting resin having a reactive group capable of reacting with a maleimide group may also be added. The thermosetting resin having a reactive group reactive with this maleimide group is a thermosetting resin other than the components (A) and (C), and is not limited to a specific type as long as it is a thermosetting resin other than the components (A) and (C), and examples thereof include various resins other than the components (A) and (C), such as phenolic resins, melamine resins, silicone resins, cyclic imide resins including maleimide compounds other than the component (A), urea resins, thermosetting polyimide resins, modified polyphenylene ether resins, thermosetting acrylic resins, and epoxy-silicone hybrid resins. Examples of reactive groups reactive with the maleimide group include maleimide groups, hydroxyl groups, acid anhydride groups, alkenyl groups such as allyl groups and vinyl groups, (meth)acrylic groups, and thiol groups.

[0045] From the viewpoint of reactivity, the reactive group of the thermosetting resin is preferably selected from a maleimide group, a hydroxyl group, and an alkenyl group, and from the viewpoint of dielectric properties, an alkenyl group or a (meth)acrylic group is more preferable. However, the amount of the thermosetting resin having a reactive group capable of reacting with a maleimide group is 0 to 60 mass % of the total amount of the thermosetting resin.

[0046] others In addition to the above, non-functional silicone oil, reactive diluent, thermoplastic resin, thermoplastic elastomer, organic synthetic rubber, photosensitizer, light stabilizer, polymerization inhibitor, flame retardant, pigment, dye, adhesion aid, ion trapping material, etc. may be blended. In addition, silane coupling agents such as epoxy group-containing alkoxysilanes, amino group-containing alkoxysilanes, (meth)acrylic group-containing alkoxysilanes, and alkenyl group-containing alkoxysilanes that are used to surface treat the above-mentioned inorganic fillers may be separately blended into the thermosetting resin film for forming a semiconductor redistribution layer of the present invention, and specific examples thereof include those similar to those described above.

[0047] Method for manufacturing thermosetting resin film for forming semiconductor rewiring layer The method for producing the thermosetting resin film for forming a semiconductor redistribution layer of the present invention is not particularly limited as long as the film can be produced by a common method, such as a method in which each component is dissolved in an organic solvent to form a varnish, which is then applied to a substrate and dried, or a method in which each component is premixed and extrusion-molded to produce a film. When preparing a varnish, any organic solvent can be used without limitation as long as it dissolves the thermosetting resin having a reactive group capable of reacting with the maleimide group as component (A) and other additives, such as anisole, tetralin, mesitylene, xylene, toluene, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone. However, aromatic organic solvents such as anisole, tetralin, mesitylene, xylene, and toluene are preferred. These may be used alone or in combination of two or more.

[0048] The varnish containing the thermosetting resin film components for forming the semiconductor rewiring layer is applied to a substrate, and the organic solvent is evaporated to form an uncured resin film, which can then be cured to form a cured resin film. Examples of production conditions for the film using the varnish are shown below, but are not limited to these.

[0049] For example, a composition (varnish) for a thermosetting resin film for forming a semiconductor redistribution layer dissolved in an organic solvent is applied to a substrate, and then a drying process is carried out, for example, by heating at a temperature of typically 80°C or higher, preferably 100°C or higher, for 0.5 to 20 minutes to remove the organic solvent, thereby producing an uncured resin film, which is the thermosetting resin film for forming a semiconductor redistribution layer of the present invention. The resulting uncured resin film can be further heated in a heat curing step at a temperature of 130°C or higher, preferably 150°C or higher, for 0.5 to 10 hours to produce a cured resin film. The resulting cured resin film has a flat, strong maleimide resin cured coating on the surface. The temperatures in the drying step for removing the organic solvent and the subsequent heat curing step may be constant, but it is preferable to increase the temperature stepwise, which allows the organic solvent to be efficiently removed from the composition and the curing reaction of the resin to proceed efficiently. The method for applying the varnish includes, but is not particularly limited to, a spin coater, a slit coater, a spray coater, a dip coater, a bar coater, and the like.

[0050] The substrate can be a general resin substrate, such as polyolefin resins such as polyethylene (PE) resin, polypropylene (PP) resin, and polystyrene (PS) resin, and polyester resins such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, and polycarbonate (PC) resin. The surface of the substrate may be subjected to a release treatment. The thickness of the coating layer is not particularly limited, but the thickness after solvent removal is in the range of 1 to 200 μm, preferably 3 to 150 μm. A cover film may also be used on the coating layer.

[0051] As another method, the components may be premixed in advance and extruded into a film using a melt kneader, which can then be used as is (extrusion molding).

[0052] Semiconductor device manufacturing method Generally used resin films for forming semiconductor redistribution layers are laminated on a base material such as a substrate, and many of them form patterns through an exposure process, a development process, and further heating processes before and after the development process as required. Such materials are suitable for forming fine wirings, but many materials have a high dielectric constant and a high dielectric tangent. As something other than the resin film for forming a semiconductor redistribution layer, there is also a method in which a varnish containing a resin composition for forming a semiconductor redistribution layer is coated on a substrate, laminated by drying the solvent, and then a redistribution layer is formed through the same processes. Similarly, many materials have a high dielectric constant and a high dielectric tangent, and this method is more common than the film material. Many of these are polyimide materials and have problems such as high hygroscopicity and the need for high temperatures for curing in addition to dielectric properties.

[0053] On the other hand, the formation of a redistribution layer using the thermosetting resin film for forming a semiconductor redistribution layer of the present invention, that is, the manufacturing method of a semiconductor device having a redistribution layer, has the following steps. (1) A step of placing the thermosetting resin film for forming a semiconductor redistribution layer of the present invention on a substrate of a semiconductor device (2) A step of heating the placed film at 80 to 130 °C for 10 to 180 seconds and laminating it on the substrate (3) A step of heat-curing the laminated film at less than 200 °C for 0.2 to 4 hours

[0054] Semiconductor devices that require dielectric properties such as a low relative dielectric constant and a low dielectric tangent for the redistribution layer are limited to applications such as high-speed communication and antennas that utilize dielectric properties, so there are not many that require fine wirings, and a thermosetting material like the present invention can be used.

[0055] Examples of the above-mentioned substrate include an inorganic substrate, a resin, and a resin composite material. Examples of the inorganic substrate include a glass substrate, a quartz substrate, a silicon substrate, a silicon nitride substrate, and a composite substrate with molybdenum, titanium, aluminum, copper, etc. vapor-deposited on these substrates. Examples of the resin substrate include substrates made of synthetic resins such as polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polystyrene, polycarbonate, polysulfone, polyethersulfone, polyarylate, allyl diglycol carbonate, polyamide, polyimide, polyamideimide, polyetherimide, polybenzazole, polyphenylene sulfide, polycycloolefin, norbornene resin, fluororesins such as polychlorotrifluoroethylene, liquid crystal polymer, acrylic resin, epoxy resin, silicone resin, ionomer resin, cyanate resin, crosslinked fumaric acid diester, cyclic polyolefin, aromatic ether, maleimide-olefin, cellulose, episulfide compound, etc.

[0056] The methods for forming the rewiring layer using a thermosetting material mainly include the following two. The first one is a method in which the thermosetting resin film for forming a semiconductor rewiring layer of the present invention is cured through the above steps (1) to (3) on a substrate on which copper wiring is formed, vias are formed by laser on the copper wiring, and copper plating is applied. The second one is a method in which the thermosetting resin film for forming a semiconductor rewiring layer of the present invention is cured through the above steps (1) to (3) on a substrate on which copper wiring is formed and copper pillars are formed on the copper wiring. At this time, the height of the film is higher than the height of the copper pillars. Then, the cured resin film layer is polished to expose the copper pillars.

Example

[0057] Hereinafter, examples and comparative examples will be shown to specifically explain the present invention, but the present invention is not limited to the following examples.

[0058] (A) Maleimide compound (A-1): A hydrocarbon group-containing bismaleimide compound (BMI-2500, manufactured by Designer Molecules Inc., solid at 25 °C) derived from a dimer acid skeleton represented by the following formula

Chemical formula

[0059] Comparative Example Compound (A-5): 4,4'-diphenylmethane bismaleimide (trade name: BMI-1000, manufactured by Daiwa Chemical Industry Co., Ltd., solid at 25°C) (A-6): Bis-(3-ethyl-5-methyl-maleimidophenyl)methane (trade name: BMI-4000, manufactured by Daiwa Chemical Industry Co., Ltd., solid at 25°C) (A-7): Aromatic bismaleimide compound represented by the following formula (trade name: BMI-6100, manufactured by Designer Molecules Inc., solid at 25°C) [Chemical formula] (A - 8): Terminal methacryl - modified polyphenylene ether resin (Trade name: SA - 9000, manufactured by SABIC)

[0060] (B) Catalyst (B - 1): Dicumyl peroxide (Trade name: Parkmill D, manufactured by NOF Corporation) (B - 2): 1 - Benzyl - 2 - phenylimidazole (Trade name: 1B2PZ, manufactured by Shikoku Kasei Co., Ltd.) (B - 3): Triphenylphosphine (Trade name: TPP, manufactured by Hokko Chemical Industry Co., Ltd.)

[0061] (C) Epoxy resin having two or more epoxy groups in one molecule (C - 1): Bisphenol A - type liquid epoxy resin (Trade name: jER - 828, manufactured by Mitsubishi Chemical Corporation) (C - 2): Polyfunctional epoxy resin (Trade name: EPPN - 501, manufactured by Nippon Kayaku Co., Ltd.)

[0062] (D) Inorganic filler (D - 1): Dispersion of spherical silica with an average particle size of 0.5 μm (solid concentration 75 mass%) in toluene slurry (Trade name: 5SV - CT1, manufactured by Admatechs Co., Ltd.)

[0063] (E) Comparative material (E - 1): Thermosetting polyimide silicone (Trade name: KJR - 655, manufactured by Shin - Etsu Chemical Co., Ltd.) (E - 2): Negative - type polyimide (Trade name: Pimer BL, manufactured by Asahi Kasei Corporation) (E - 3): Low - temperature - curing negative - type polyimide (Trade name: LTC9300, manufactured by Fujifilm Corporation)

[0064] Preparation of resin varnish The components shown in Tables 1 and 2 were added to a 500 mL four-neck flask equipped with a Dimroth condenser and a stirrer, stirred at 80°C for 4 hours, and filtered through a 100-mesh wire screen to obtain a varnish-like resin composition. (E-1) to (E-3) were used as received.

[0065] <Preparation of uncured and cured resin films> The varnish-like resin composition prepared above was applied to a 50 μm-thick release-treated PET film (TN-010, manufactured by Toyobo STC) using a roller coater and dried for 10 minutes at 120°C to obtain a 50 μm-thick uncured resin film. This uncured resin film was fixed directly onto a flat plate together with the release-treated PET film and cured in a nitrogen atmosphere at 180°C for 2 hours to obtain a cured resin film. For (E-1) to (E-3), the resins were applied to a 50 μm-thick release-treated PET film (TN-010, manufactured by Toyobo STC) using a roller coater and dried at 150°C for 60 minutes to obtain a 50 μm-thick uncured resin film. This uncured resin film was fixed in place with a jig and cured at 200°C for 1 hour and then at 250°C for 4 hours to obtain a cured resin film.

[0066] <Relative permittivity, dielectric loss tangent> Using the cured resin film, a network analyzer (manufactured by Keysight, product name: E5063-2D5) and a strip line (manufactured by Keycom Corporation) were connected, and the relative dielectric constant and dielectric loss tangent of the cured resin film at frequencies of 10 GHz and 40 GHz were measured.

[0067] <Dielectric constant and dielectric loss tangent after moisture absorption> The cured resin film was left in a thermostatic chamber at a temperature of 85° C. and a humidity of 85% for 24 hours, and the relative dielectric constant and dielectric loss tangent at a frequency of 10 GHz were measured by the above-mentioned method.

[0068] <Lamination test> Using the above method, an uncured resin film with a 210 mm × 210 mm PET film was prepared. The uncured resin film was placed on an 8-inch Si wafer such that the resin film surface without the PET film in contact, and lamination was performed using a batch-type vacuum laminator (manufactured by Nippon Materials Co., Ltd.) under the conditions of 100°C, 0.5 MPa pressure, and 60 seconds. Those that could be laminated on the wafer were marked as 〇, and those that could not be laminated were marked as ×. Also, those that could not be treated as an uncured resin film due to excessive tack were marked as -.

[0069] <Peel strength> An SUS304 plate with a length of 75 mm, a width of 25 mm, and a thickness of 1.0 mm was prepared. The above uncured resin film with a PET film was placed on one surface of the plate such that the resin film surface was in contact, and lamination was performed under the conditions of 100°C, 0.3 MPa pressure, and 60 seconds. After lamination, the PET film was peeled off, and an 18-μm-thick copper foil (Rz: 0.6 μm) was placed in contact with the resin film surface, and lamination was performed under the conditions of 100°C, 0.5 MPa pressure, and 60 seconds. After lamination, it was heated at 130°C for 30 minutes and then further heated at 170°C for 30 minutes to cure and produce an adhesion test piece. To evaluate the adhesiveness, in accordance with JIS C6481:1996, the 90° peel adhesion strength (kN / m) when peeling the copper foil of each adhesion test piece from a slide glass was measured under the conditions of a temperature of 23°C and a tensile speed of 50 mm / min. Note that this test was only carried out for those that were evaluated as 〇 in the lamination test just now.

[0070]

Table 1

[0071]

Table 2

[0072]

Table 3

Claims

1. (A) A maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule and (B) A catalyst selected from one or more of a thermal radical polymerization initiator or an anionic polymerization initiator containing wherein the component (A) is one or more selected from any of the following formula (1), formula (2), and formula (3), and one or more of these are solids at 25°C, a thermosetting resin film for forming a semiconductor rewiring layer. 【Chemical 1】 (In formula (1), A is independently a tetravalent organic group having a cyclic structure, B is independently a divalent hydrocarbon group having 6 to 60 carbon atoms, D is independently a divalent hydrocarbon group having 6 to 200 carbon atoms, one or more of D are hydrocarbon groups derived from a dimer acid skeleton, b is 1 to 100, and a is 1 to 100. The order of each repeating unit enclosed by b and a is not limited, and the bonding mode is alternating, block, or random.) 【Chemical Formula 2】 (In formula (2), A and D are the same as in formula (1) above, and c is 1 to 100.) [Chemical 3] (In formula (3), D represents a hydrocarbon group derived from a dimer acid skeleton.)

2. The thermosetting resin film for forming a semiconductor rewiring layer according to claim 1, wherein A in the formula (1) or formula (2) is any of the tetravalent organic groups represented by the following formula. [Chemical Formula 4]

3. The thermosetting resin film for forming a semiconductor rewiring layer according to claim 1, wherein the component (B) is an anionic polymerization initiator, and further contains (C) an epoxy resin having two or more epoxy groups in one molecule.

4. A semiconductor device having a rewiring layer, comprising a cured product of the thermosetting resin film for forming a semiconductor rewiring layer according to any one of claims 1 to 3.

5. A method for manufacturing a semiconductor device having a rewiring layer, comprising a cured product of the thermosetting resin film for forming a semiconductor rewiring layer according to any one of claims 1 to 3, (1) A step of placing the thermosetting resin film for forming a semiconductor rewiring layer on a substrate of a semiconductor device, (2) A step of heating the placed film at 80 to 130°C for 10 to 180 seconds and laminating it on the substrate, and (3) A step of heating and curing the laminated film at less than 200°C for 0.2 to 4 hours, a method for manufacturing a semiconductor device having.

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