Resin composition, semiconductor device, and method for producing semiconductor device

Abstract

Provided is a resin composition for wafer level chip-size package-type semiconductor devices, wherein the resin composition can form a coating film that exhibits good high-frequency characteristics, little variability in thickness, and resistance to the generation of warping in the semiconductor substrate. Also provided are a semiconductor device and semiconductor device production method that use this resin composition.　The resin composition for wafer level chip-size package-type semiconductor devices comprises a modified polyphenylene ether resin (A) having an unsaturated double bond in terminal position, an elastomer (B) having a butadiene skeleton, and optionally a solvent (C). The semiconductor device and semiconductor device production method use this resin composition.

Description

Resin composition, semiconductor device, and method for manufacturing semiconductor device

[0001] The present invention relates to a resin composition, a semiconductor device using the same, and a method for manufacturing a semiconductor device.

[0002] As electronic devices become smaller, lighter, and more functional, there is a demand for smaller, lighter, and more highly densely mounted semiconductor packages. In response to this trend, a semiconductor packaging technology called wafer-level chip size packaging (WL-CSP) has been proposed. Wafer-level chip size packaging is a semiconductor package that does not use internal wiring with bonding wires, leaving a portion of the semiconductor substrate (silicon wafer) exposed, and is roughly the same size as the semiconductor substrate.

[0003] For example, WL-CSP is disclosed in Patent Documents 1 and 2. WL-CSP has a multilayer structure including electrodes, an insulating layer, a rewiring layer, and a sealing resin layer on a semiconductor substrate (silicon wafer), and external terminals such as solder bumps.

[0004] JP 2017-92152 A JP 2010-192938 A

[0005] As information transmission speeds become ultra-high and the volume of information increases, high-frequency characteristics are required for electronic components, and WL-CSPs mounted on electronic components are also required to have high-frequency characteristics. For example, they are required to have excellent electrical characteristics (low dielectric constant (ε) and low dielectric loss tangent (tan δ)) in the high-frequency range, specifically in the frequency range of 1 GHz to 10 GHz.

[0006] In WL-CSP, a resin composition is applied to a semiconductor substrate (silicon wafer) using a rotary spin coater to form an interlayer insulating film. However, depending on the resin material, when the resin composition is applied to the semiconductor substrate using a spin coater, a uniform coating film may not be formed on the semiconductor substrate, or the semiconductor substrate may warp due to shrinkage or the like during curing of the resin composition after application.

[0007] Therefore, an object of the present invention is to provide a resin composition for wafer-level chip size package type semiconductor devices that has good high-frequency characteristics, has little variation in thickness even when applied to a semiconductor substrate using a spin coater, and is capable of forming a coating film that is less likely to cause warping of the semiconductor substrate, as well as a semiconductor device and a method for manufacturing a semiconductor device using the same.

[0008] The means for solving the above problems are as follows, and the present invention includes the following aspects.

[0009] [1] A resin composition for a wafer-level chip size package type semiconductor device, comprising: (A) a modified polyphenylene ether resin having an unsaturated double bond at its terminal; and (B) an elastomer having a butadiene skeleton. [2] The modified polyphenylene ether resin having an unsaturated double bond at its terminal (A) is represented by the following formula (1): [In formula (1), X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, and Y represents a group represented by the following formula (2): [In formula (2), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkenylcarbonyl group, Z represents a functional group containing a terminal carbon-carbon double bond, and is selected from the group consisting of a vinyl group, a vinylene group, and a group represented by the following formula (3): [In formula (3), R ５ represents a hydrogen atom or an alkyl group.], or a (meth)acryloyl group represented by the following formula (4): [In formula (4), R ６ ~R ８each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group.] represents a styrene group represented by the formula (3), m represents an integer of 1 to 100, n represents 0 or an integer of 1 to 6, and p represents an integer of 1 to 4.] [3] The resin composition according to the above item (1) or (2), wherein the (B) elastomer having a butadiene skeleton comprises at least one selected from the group consisting of a styrene / butadiene / styrene copolymer, a styrene / butadiene / butylene / styrene copolymer, a butadiene polymer, a styrene / butadiene copolymer, and an acrylonitrile / butadiene copolymer. [4] The (A) modified polyphenylene ether resin having an unsaturated double bond at a terminal is represented by the following formula (5): [In formula (5), R ５ represents a hydrogen atom or an alkyl group, X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, Y represents an unsubstituted or substituted phenol repeating unit represented by the formula (2), m represents an integer of 1 to 100, n represents 0 or an integer of 1 to 6, and p represents an integer of 1 to 4.] and a modified polyphenylene ether resin represented by the following formula (6): [In formula (6), R ６ ~R ８ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, Y represents an unsubstituted or substituted phenol repeating unit represented by formula (2), m represents an integer of 1 to 100, n represents 0 or an integer of 1 to 6, and p represents an integer of 1 to 4. [5] The resin composition according to any one of items [1] to [3] above, wherein the (B) elastomer having a butadiene skeleton is at least one selected from the group consisting of modified polyphenylene ether resins represented by formula (7): [In formula (7), at least one of q and r is an integer of 0 to 1, s is an integer of 1 to 1200, and t is an integer of 1 to 1000, and a styrene / butadiene / styrene block copolymer represented by the following formula (8):[In formula (8), u represents an integer of 1 to 1200, and v represents an integer of 1 to 1000.] The resin composition according to any one of [1] to [4] above, comprising at least one selected from the group consisting of acrylonitrile / butadiene copolymers represented by the formula (8). [6] The resin composition according to any one of [1] to [5] above, wherein the (A) modified polyphenylene ether resin having an unsaturated double bond at a terminal comprises a modified polyphenylene ether resin represented by the formula (6), and the (B) elastomer having a butadiene skeleton comprises a styrene / butadiene / styrene copolymer represented by the formula (7). [7] The resin composition according to any one of [1] to [6] above, further comprising (C) a solvent. [8] The resin composition according to [7] above, wherein a first viscosity at 25°C and 10 rpm measured with a rotational viscometer is in the range of 300 mPa·s to 4000 mPa·s. [9] The resin composition according to [8] above, wherein the second viscosity measured at 25°C and 1 rpm using a rotational viscometer is within the range of 500 mPa·s to 4200 mPa·s, and the thixotropy index TI, which is the ratio of the second viscosity to the first viscosity, is 0.8 to 1.2.

[10] The resin composition according to any one of [1] to [9] above, wherein the mass ratio of component (A) to component (B) is within the range of 10:90 to 80:20.

[11] The resin composition according to any one of [7] to

[10] above, wherein the mass ratio of the total amount of component (A) and component (B) to component (C) is within the range of 5:95 to 80:20.

[12] A wafer-level chip size package type semiconductor device comprising: a semiconductor substrate; electrodes arranged on the semiconductor substrate; wiring electrically connected to the electrodes; external terminals electrically connected to the electrodes via the wiring; and an interlayer insulating film sealing the side of the semiconductor substrate on which the electrodes and wiring are arranged, the interlayer insulating film being arranged to contact the wiring, and the semiconductor device being made using the resin composition described in any of [1] to

[11] .

[13] The semiconductor device described in

[12] above, comprising at least two layers: a first interlayer insulating film sealing the semiconductor substrate side of the wiring, and a second interlayer insulating film sealing the opposite side of the wiring from the semiconductor substrate.

[14] The semiconductor device according to

[12] or

[13] , wherein the thickness of one of the interlayer insulating film, the first interlayer insulating film, or the second interlayer insulating film is within the range of 3 μm to 20 μm.

[15] A method for manufacturing a wafer-level chip size package type semiconductor device, comprising: preparing a liquid resin composition containing the following components (A) to (C): (A) a modified polyphenylene ether resin having an unsaturated double bond at a terminal, (B) an elastomer having a butadiene skeleton, and (C) a solvent; dropping the resin composition onto a semiconductor substrate and rotating the semiconductor substrate about a vertical axis using a spin coater to apply the liquid resin composition to the semiconductor substrate; and curing the liquid resin composition to form an interlayer insulating film.

[16] The method for manufacturing a semiconductor device according to

[15] , wherein the rotation speed of the spin coater is 1000 rpm to 3000 rpm and the rotation time is 5 seconds to 30 seconds.

[17] The method for manufacturing a semiconductor device according to

[15] or

[16] , wherein the liquid resin composition has a first viscosity of 300 mPa·s to 4000 mPa·s at 25°C and 10 rpm as measured by a rotational viscometer.

[18] The method for manufacturing a semiconductor device according to

[17] , wherein the liquid composition has a second viscosity of 500 mPa·s to 4200 mPa·s as measured by a rotational viscometer at 25°C and 1 rpm as measured by a rotational viscometer, and a thixotropy index TI, which is the ratio of the second viscosity to the first viscosity, of 0.8 to 1.2.

[19] The method for producing a semiconductor device according to any one of

[15] to

[18] above, wherein the (A) modified polyphenylene ether resin having an unsaturated double bond at a terminal thereof comprises a polyphenylene ether resin represented by formula (1) above, and the (B) elastomer having a butadiene skeleton comprises at least one selected from the group consisting of a styrene / butadiene / styrene copolymer, a styrene / butadiene / butylene / styrene copolymer, a butadiene polymer, a styrene / butadiene copolymer, and an acrylonitrile / butadiene copolymer.

[0010] According to the present invention, it is possible to provide a resin composition for wafer-level chip size package type semiconductor devices, which has good high-frequency characteristics, has little variation in thickness even when applied to a semiconductor substrate using a spin coater, and is capable of forming a coating film that is less likely to cause warping of the semiconductor substrate, as well as a semiconductor device and a method for manufacturing a semiconductor device using the same.

[0011] FIG. 1 is a schematic cross-sectional view showing the schematic configuration of a part of a WL-CSP type semiconductor device.

[0012] Hereinafter, a resin composition for a wafer-level chip size package type semiconductor device, a semiconductor device using the same, and a method for manufacturing the semiconductor device according to the present disclosure will be described based on embodiments. However, the embodiments shown below are merely examples for embodying the technical concept of the present invention, and the present invention is not limited to the following resin composition, the semiconductor device using the same, and the method for manufacturing the semiconductor device.

[0013] The resin composition according to the first embodiment of the present invention contains a specific modified polyphenylene ether (also referred to as "component (A)") and (B) an elastomer having a butadiene skeleton (also referred to as "component (B)"). Because the resin composition contains the modified polyphenylene ether of component (A), the dielectric constant (ε) of a coating film formed from a cured product of the resin composition constituting the interlayer insulating film is preferably 3.0 or less, more preferably 2.9 or less, even more preferably 2.8 or less, and particularly preferably 2.7 or less. The dielectric constant (ε) of a coating film formed from a cured product of the resin composition constituting the interlayer insulating film may be 1.0 or more, and is preferably 1.5 or more. The dielectric loss tangent (tan δ) of a coating film formed from the resin composition constituting the interlayer insulating film is preferably 0.015 or less, more preferably 0.014 or less, and even more preferably 0.013 or less. The dielectric loss tangent (tan δ) of a coating film formed from the resin composition constituting the interlayer insulating film is preferably 0.001 or more. If the coating film made of a resin composition constituting the interlayer insulating film of a WL-CSP type light emitting device has a relative dielectric constant of 3.0 or less and a dielectric loss tangent (tan δ) of 0.015 or less, the coating film has a low dielectric constant and a low dielectric loss tangent, and exhibits good electrical properties when used in high-frequency regions. For example, a coating film with good electrical properties can be obtained even when semiconductor devices are used in high-frequency regions such as the fifth-generation communication system "5G," which is expected to increase capacity and speed.

[0014] Since the resin composition contains component (A) and component (B), the resin composition applied to a semiconductor substrate shrinks uniformly when cured, making the semiconductor substrate less likely to warp. Therefore, the resin composition containing component (A) and component (B) is suitable for forming an interlayer insulating film in a WL-CSP type semiconductor device.

[0015] The resin composition preferably further contains, in addition to component (A) and component (B), a solvent (C) (also referred to as "component (C)") as needed. A resin composition containing component (C) in addition to components (A) and (B) has good thixotropy. A resin composition containing component (C) in addition to components (A) and (B) can form a coating film of approximately uniform thickness with little variation in thickness even when applied to a semiconductor substrate using, for example, a spin coater.

[0016] The resin composition containing component (A), component (B), and component (C) preferably has a first viscosity in the range of 300 mPa·s to 4000 mPa·s at 25°C and 10 rpm as measured with a rotational viscometer. If the first viscosity of the resin composition is in the range of 300 mPa·s to 4000 mPa·s, even when applied to a semiconductor substrate using, for example, a spin coater, a coating film of approximately uniform thickness can be formed with little variation in thickness, and warping of the semiconductor substrate during curing can be suppressed. The resin composition more preferably has a first viscosity of 400 mPa·s to 4000 mPa·s, and even more preferably 500 mPa·s to 2000 mPa·s. In this specification, the rotational viscometer can be measured using, for example, a TVE-type viscometer (cone rotor: 1°34' x R24, manufactured by Toki Sangyo Co., Ltd.).

[0017] The resin composition containing components (A), (B), and (C) preferably has a second viscosity in the range of 500 mPa·s to 4200 mPa·s at 25°C and 1 rpm as measured with a rotational viscometer. If the second viscosity of the resin composition is in the range of 500 mPa·s to 4200 mPa·s, even when applied to a semiconductor substrate using, for example, a spin coater, there is little variation in thickness, making it possible to form a coating film of approximately uniform thickness, and warping of the semiconductor substrate during curing can be suppressed. The second viscosity of the resin composition is more preferably in the range of 550 mPa·s to 4000 mPa·s, and even more preferably in the range of 550 mPa·s to 3500 mPa·s.

[0018] The resin composition containing components (A), (B), and (C) preferably has a thixotropy index (TI), which is the ratio of the second viscosity to the first viscosity, in the range of 0.8 to 1.2, and thus has thixotropy similar to that of a Newtonian fluid. Here, a Newtonian fluid refers to a fluid in which shear stress is proportional to shear rate. If the thixotropy index (TI), which is the ratio of the second viscosity to the first viscosity of the resin composition, is in the range of 0.8 to 1.2, then even when applied to a semiconductor substrate using, for example, a spin coater, thickness variation is reduced, allowing for the formation of a coating film of substantially uniform thickness, and warping of the semiconductor substrate upon curing can be suppressed. The thixotropy index (TI), which is the ratio of the second viscosity to the first viscosity of the resin composition, may be in the range of 0.90 to 1.10, or may be in the range of 1.00 to 1.10.

[0019] In the resin composition, the mass ratio of component (A) to component (B) is preferably within the range of 10:90 to 80:20, more preferably within the range of 20:80 to 75:25, and even more preferably within the range of 30:70 to 70:30. When the mass ratio of component (A) to component (B) in the resin composition is within the range of 10:90 to 80:20, the resin composition can be used to obtain a cured product having a low dielectric constant and a low dielectric loss tangent, and exhibiting good electrical properties when used in the high frequency range. Furthermore, even when the resin composition is applied to a semiconductor substrate using, for example, a spin coater, the thickness can be varied little, allowing the formation of a coating film of substantially uniform thickness, resulting in a cured product that suppresses warping of the semiconductor substrate.

[0020] In the resin composition, the mass ratio of the total amount of component (A) and component (B) to component (C) is preferably within the range of 5:95 to 80:20, more preferably within the range of 10:90 to 70:30, even more preferably within the range of 12:88 to 40:60, and particularly preferably within the range of 18:82 to 50:50. If the component mass ratio of the total amount of component (A) and component (B) in the resin composition is within the range of 5:95 to 80:20, even when the resin composition is applied to a semiconductor substrate using, for example, a spin coater, there is little variation in thickness, and a coating film of approximately uniform thickness can be formed, and a cured product can be obtained that suppresses warping of the semiconductor substrate.

[0021] Component (A) Modified Polyphenylene Ether Component (A) is preferably a polyphenylene ether resin having a functional group containing a carbon-carbon double bond at its terminal. The modified polyphenylene ether (PPE) resin is also referred to as component (A) or a modified PPE resin of component (A). Examples of the functional group containing a carbon-carbon double bond include a terminal vinyl group, a vinylene group, a vinylidene group, an acryloyl group, or a methacryloyl group. Component (A) is not particularly limited as long as it has a functional group containing a carbon-carbon double bond at its terminal and has a polyphenylene ether skeleton. The inclusion of component (A) can impart low dielectric properties to the resin composition and improve heat resistance and the thermal expansion coefficient. Component (A) is preferably a thermosetting resin. Component (A) is particularly preferably a polyphenylene ether resin having a terminal vinyl group. Having a terminal vinyl group can provide low dielectric properties.

[0022] The modified PPE resin of component (A) preferably contains a PPE resin represented by the following formula (1): [In formula (1), X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, and Y represents a group represented by the following formula (2): [In formula (2), R １ ~R ４each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkenylcarbonyl group, Z represents a functional group containing a terminal carbon-carbon double bond, and is selected from the group consisting of a vinyl group, a vinylene group, and a group represented by the following formula (3): [In formula (3), R ５ represents a hydrogen atom or an alkyl group.] or a (meth)acryloyl group represented by the following formula (4): [In formula (4), R ６ ~R ８ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group.] m represents an integer of 1 to 100, n represents 0 or an integer of 1 to 6, and p represents an integer of 1 to 4.]

[0023] The PPE resin of component (A) preferably contains at least one type selected from the group consisting of modified PPE resins represented by the following formula (5) and modified PPE resins represented by the following formula (6).

[0024] [In formula (5), R ５ represents a hydrogen atom or an alkyl group, X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, Y represents an unsubstituted or substituted phenol repeating unit represented by the formula (2), m represents an integer of 1 to 100, n represents 0 or an integer of 1 to 6, and p represents an integer of 1 to 4.

[0025] [In formula (6), R ６ ~R ８ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, Y represents an unsubstituted or substituted phenol repeating unit represented by the formula (2), m represents an integer of 1 to 100, n represents 0 or an integer of 1 to 6, and p represents an integer of 1 to 4.

[0026] Generally, an x-valent (x is an integer of 1 or greater) hydrocarbon group refers to an x-valent group generated by removing x hydrogen atoms from a carbon atom of a hydrocarbon. X is a p-valent unsubstituted or substituted aromatic hydrocarbon group, and X refers to a mono- to tetravalent group generated by removing 1 to 4 hydrogen atoms from a carbon atom of an aromatic hydrocarbon, which may or may not be substituted.

[0027] The term "alkyl group" means a monovalent saturated hydrocarbon group. In the present invention, the alkyl group is preferably C １ -C １０ alkyl group, more preferably C １ -C ６ alkyl group, more preferably C １ -C ４ Alkyl groups, particularly preferably C １ -C ２ Examples of such alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl groups.

[0028] The term "alkenyl group" means a monovalent unsaturated hydrocarbon group having at least one carbon-carbon double bond. In the present invention, the alkenyl group is preferably C ２ -C １０ Alkenyl groups, more preferably C ２ -C ６ Alkenyl groups, more preferably C ２ -C ４ It is an alkenyl group. Examples of such an alkenyl group include ethenyl group (vinyl group), 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, isobutenyl group, 1-pentenyl group, and 1-hexenyl group. The group -CR in the formula (1) １ =CR ２ R ３ is also an alkenyl group.

[0029] The term "alkynyl group" means a monovalent unsaturated hydrocarbon group having at least one carbon-carbon triple bond. In the present invention, an alkynyl group is preferably C ２ -C１０ Alkynyl groups, more preferably C ２ -C ６ Alkynyl groups, more preferably C ２ -C ４ An alkynyl group. Examples of such an alkynyl group include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a butynyl group, an isobutynyl group, a pentynyl group, and a hexynyl group.

[0030] The term "alkenylcarbonyl group" means a carbonyl group substituted with the above-mentioned alkenyl group, and examples thereof include an acryloyl group and a methacryloyl group.

[0031] In component (A), in formula (1), (5) or (6), -(Y) ｍ The portion represented by - corresponds to the main chain of the PPE resin. １ and R ３ represents a hydrogen atom, and R ２ and R ４ represents a methyl group. ｍ One end of the moiety represented by - is bonded to the aromatic hydrocarbon group X via an oxygen atom, and the other end is bonded to the terminal group (Z) via n methylene groups. ｍ One end of the moiety represented by - is bonded to the aromatic hydrocarbon group X via an oxygen atom, and the other end is bonded to the methacryloyl group via n methylene groups. ｍ One end of the moiety represented by - is bonded to the aromatic hydrocarbon group X via an oxygen atom, and the other end is bonded to the alkenyl group -CR via n methylene groups. ６ =CR ７ R ８ may be located at the ortho, meta, or para position relative to the methylene group. In one embodiment, n in formula (1), (5), or (6) is 0 or an integer from 1 to 4. In one embodiment, n in formula (1), (5), or (6) is 0, 1, or 2. In another embodiment, n in formula (1) is 0 or 1. In another embodiment, R in formula (6) ６~R ８ are all hydrogen atoms.

[0032] The number m of Y in the repeating units of formula (1), (5) or (6) is preferably 1 to 80, more preferably 1 to 30, and even more preferably 1 to 5.

[0033] In component (A), the aromatic hydrocarbon group X of formula (1), (5) or (6) is each connected via an oxygen atom to p -(Y) ｍ Preferably, p is 2 or 3. More preferably, p is 2. Furthermore, X is preferably a group represented by the following formula: [In the formula, R １１ ~R １８ are each independently a hydrogen atom or C １ -C ６ X is more preferably a group represented by the following formula: It has a structure represented by the following formula:

[0034] The main chain terminal of the modified polyphenylene ether resin of component (A) may be a polyphenylene ether resin having an average of 1.5 to 5 functional groups represented by formula (1), (5), or (6) per molecule. The terminal functional groups are preferably methacryloyl groups and / or acryloyl groups from the viewpoint of imparting even better heat resistance when the resin composition is cured, and more preferably methacryloyl groups from the viewpoint of providing even better resin fluidity during thermoforming.

[0035] For example, from the viewpoints of ease of application of the resin composition to a semiconductor substrate using a spin coater, electrical properties such as low dielectric properties and low dielectric dissipation factor of a coating film made of the resin composition, and compatibility with other components contained in the resin composition, the number average molecular weight of component (A) is preferably 500 or more and 5,000 or less. The number average molecular weight of component (A) is more preferably 750 or more and 3,000 or less, and even more preferably 1,000 or more and 2,500 or less. If the number average molecular weight (Mn) of component (A) is too low, the toughness of the cured product obtained by curing the resin composition may decrease. On the other hand, if the number average molecular weight (Mn) of component (A) is too high, the compatibility of component (A) with the solvent of component (C) may decrease, making it difficult to apply the resin composition to a semiconductor substrate using, for example, a spin coater. The number average molecular weight (Mn) of component (A) or component (B) can be measured, for example, from the polystyrene equivalent value measured by gel permeation chromatography (GPC). In this specification, the number average molecular weight (Mn) can be measured, for example, using high performance liquid chromatography (e.g., LC-2OAD, manufactured by Shimadzu Corporation) with a column (e.g., KF-802, manufactured by Showa Denko K.K.) and a tetrahydrofuran (THF) solution as a solvent.

[0036] The content of component (A) in the resin composition is preferably 5.0 to 40.0 mass%, more preferably 7.0 to 35.0 mass%, even more preferably 8.0 to 30.0 mass%, and particularly preferably 9.0 to 25.0 mass%, relative to 100 mass% of the total amount of components (A), (B), and (C). When the content of component (A) is 5.0 to 40.0 mass%, relative to 100 mass% of the total amount of components (A), (B), and (C) in the resin composition, a cured product having a low dielectric constant and a low dielectric loss tangent can be obtained, and a cured product having good electrical properties suitable for use in the high frequency range can be obtained.

[0037] Commercially available products can be used for component (A). As a commercially available product of component (A), the modified PPE resin represented by formula (5) can be, for example, NORYL SA9000 (manufactured by SABIC Innovative Plastics), which is a modified PPE resin represented by formula (3) having 1.5 to 5 terminal methacryloyl groups per molecule. As a commercially available product of component (A), the modified PPE resin represented by formula (6) can be, for example, OPE 2St 1200 or OPE 2St 2200 (manufactured by Mitsubishi Gas Chemical Company, Inc.). Component (A) can be prepared by a known method. For example, X-(OH) ｐ (wherein X and p have the same meanings as above) and a suitable p-hydric phenol (such as 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diol) having the structure represented by the following formula: [In the formula, R １ ~R ４ and each have the same meaning as defined above.], by a known method, to prepare a polyphenylene ether resin having hydroxyl groups at its ends, and then modifying the resulting resin by reaction with a suitable modifying agent, for example, chloromethylstyrene, to prepare component (A).

[0038] Component (B) Elastomer Having a Butadiene Skeleton The component (B) elastomer having a butadiene skeleton is sufficient as long as it has a butadiene skeleton in the molecule, and may also be a partially hydrogenated elastomer. Examples of the butadiene skeleton elastomer include block copolymers containing a block of styrene or its analog as at least one end block and an elastomer block of a conjugated diene as at least one middle block. The component (B) elastomer having a butadiene skeleton preferably contains at least one species selected from the group consisting of styrene / butadiene / styrene copolymer (SBS), styrene / butadiene / butylene / styrene copolymer (SBBS), butadiene copolymer (BR), styrene / butadiene copolymer (SBR), and acrylonitrile / butadiene copolymer (NBR). The butadiene skeleton elastomer may also be partially modified, such as carboxylated nitrilobutadiene rubber (NBR) in which the terminals are modified with carboxyl groups.

[0039] Resin compositions containing component (A) and component (B), an elastomer having a butadiene skeleton, shrink more uniformly upon curing, thereby suppressing warpage of semiconductor substrates. Furthermore, when a solvent for component (C) is used in the resin composition, the resin composition is easily soluble in the solvent, exhibiting improved thixotropy. For example, when applied to a semiconductor substrate using a spin coater, the resin composition exhibits less thickness variation and can form a coating film of substantially uniform thickness. In particular, styrene-based elastomers containing double bonds are preferred from the viewpoint of providing good electrical properties when used in the high-frequency range. Suitable examples include styrene-based elastomers containing styrene / butadiene / styrene copolymer (SBS), styrene / butadiene / butylene / styrene copolymer (SBBS), and styrene / butadiene copolymer. Furthermore, component (B) may be a reactive elastomer to which a functional group such as an amine has been added. Using a reactive elastomer to which a functional group has been added can further improve adhesive strength (peel strength). The weight average molecular weight of component (B) is preferably 20,000 to 200,000, and more preferably 30,000 to 150,000. The weight average molecular weight is determined by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0040] The elastomer having a butadiene skeleton of component (B) preferably contains at least one selected from the group consisting of a styrene / butadiene / styrene block copolymer represented by the following formula (7) and an acrylonitrile / butadiene copolymer represented by the following formula (8):

[0041] [In formula (7), q and r each represent an integer of 0 to 1, with at least one of them not being 0, s represents an integer of 1 to 1200, and t represents an integer of 1 to 1000.]

[0042] [In formula (8), u represents an integer of 1 to 1200, and v represents an integer of 1 to 1000.]

[0043] The styrene / butadiene / styrene block copolymer (SBS) of component (B) represented by formula (7) is an unhydrogenated block copolymer. By including the styrene / butadiene / styrene block copolymer in component (B), the resin composition exhibits improved flexibility and solubility in solvents, allowing the resin composition to be easily applied to a semiconductor substrate using a spin coater. Even when the resin composition contains a partially hydrogenated elastomer, such as styrene / butadiene / butylene / styrene copolymer (SBBS), the resin composition can be easily applied to a semiconductor substrate. On the other hand, it is preferable that the resin composition or component (B) does not contain an elastomer lacking a double bond. An example of an elastomer lacking a double bond is a styrene / ethylene / butylene / styrene block copolymer (SEBS), which is a fully hydrogenated styrene / butadiene / styrene block copolymer. SEBS reduces compatibility with the solvent of component (C), preventing the resin composition from achieving the desired viscosity, which can make it difficult to apply the resin composition to a semiconductor substrate using, for example, a spin coater. Although the details of the mechanism are not clear, it is presumed that styrene / butadiene / styrene block copolymer (SBS) and styrene / butadiene / butylene / styrene copolymer (SBBS) have remaining butadiene double bonds, and therefore have improved solubility in solvents compared to styrene / ethylene / butylene / styrene block copolymer (SEBS). However, the present invention is not bound by this theory.

[0044] In formula (7), s may represent an integer of 1 to 1200, or an integer of 150 to 900. In formula (7), t may represent an integer of 1 to 1000, or an integer of 50 to 700.

[0045] Furthermore, when component (B) contains an acrylonitrile / butadiene copolymer (NBR) represented by formula (8), if a solvent for component (C) is used in the resin composition, the NBR is easily dissolved in the solvent for component (C), and the thixotropy becomes better. For example, even when the resin composition is applied to a semiconductor substrate using a spin coater, the thickness varies little, and a coating film with a more uniform thickness can be formed.

[0046] The styrene content of component (B) in the resin composition is preferably in the range of 10% by mass to 70% by mass, more preferably 15% by mass to 60% by mass, and even more preferably 20% by mass to 55% by mass, based on 100% by mass of the resin composition. When the styrene content of component (B) in the resin composition is in the range of 10% by mass to 70% by mass, based on 100% by mass of the resin composition, the resin composition exhibits good elasticity upon curing, and when applied to a semiconductor substrate, for example, warping of the semiconductor substrate upon curing can be suppressed. The styrene content of component (B) in the resin composition can be measured using nuclear magnetic resonance (NMR). Specifically, using tetrachloroethane as a solvent, the integral value of the peak in the range of 5.5 ppm to 6.5 ppm, which corresponds to styrene, and the integral value of the peaks in other ranges are determined, and the styrene content can be calculated from the obtained values.

[0047] The styrene / butadiene ratio (%, mass ratio) of component (B) may be 15 / 85 or more, or 20 / 80 or more, preferably 70 / 30 or less, and may be 60 / 40 or less, or 55 / 45 or less. For example, in consideration of the uniformity of the coating film thickness when the resin composition is applied to a semiconductor substrate using a spin coater, the suppression of warping of the semiconductor substrate when the resin composition is cured, and the compatibility of the solvent of component (C), the number average molecular weight (Mn) of component (B) is preferably 40,000 or more and 600,000 or less, more preferably 50,000 or more and 150,000 or less, and even more preferably 60,000 or more and 120,000 or less. The number average molecular weight (Mn) of component (B) can be measured in the same manner as above, for example, from the polystyrene equivalent value measured by gel permeation chromatography (GPC).

[0048] The resin composition preferably contains a modified polyphenylene ether resin represented by formula (6) as component (A) and a styrene / butadiene / styrene copolymer (SBS) as component (B). Because the resin composition contains the modified PPE resin represented by formula (6) as component (A) and SBS as component (B), the resin composition applied to a semiconductor substrate shrinks uniformly upon curing, making the semiconductor substrate less likely to warp. Therefore, the resin composition is suitable for forming an interlayer insulating film in a WL-CSP type semiconductor device.

[0049] The content of component (B) in the resin composition is preferably 5.0 to 40.0% by mass, more preferably 7.0 to 35.0% by mass, even more preferably 8.0 to 30.0% by mass, and particularly preferably 9.0 to 25.0% by mass, relative to 100% by mass of the total amount of components (A), (B), and (C). When the content of component (B) is 5.0 to 40.0% by mass, relative to 100% by mass of the total amount of components (A), (B), and (C) in the resin composition, a cured product having a low dielectric constant and a low dielectric loss tangent can be obtained, and a cured product having good electrical properties suitable for use in the high frequency range can be obtained. Furthermore, when the content of component (B) in the resin composition is 5.0 to 40.0% by mass relative to the total amount of components (A), (B), and (C) in the resin composition (100% by mass), there is little variation in thickness when the resin composition is applied to a semiconductor substrate using, for example, a spin coater, and a coating film of approximately uniform thickness can be formed, and a cured product that suppresses warping of the semiconductor substrate can be obtained.

[0050] Commercially available products of component (B) can be used, such as those manufactured by JSR Corporation under the trade names "TR2827," "TR2000," "TR2003," and "TR2250," those manufactured by Asahi Kasei Chemicals Corporation under the trade names "P1083," "P1500," "P5051," and "MP10," and those manufactured by Zeon Corporation under the trade name "Nipol (trademark) 1072."

[0051] Component (C) Solvent The resin composition preferably contains a solvent for component (C). The solvent for component (C) is preferably an organic solvent. The organic solvent is preferably one in which components (A) and (B) are easily dissolved or dispersed. When the resin composition is applied to a semiconductor substrate using, for example, a spin coater, it is possible to form a coating film of approximately uniform thickness with little thickness variation, and it is less likely to remain in the coating film, thereby suppressing deterioration of dielectric properties. The organic solvent preferably contains at least one selected from the group consisting of aromatic solvents and ketone solvents. The solvent for component (C) is preferably at least one selected from the group consisting of toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexanenone, cyclohexane, dimethyl carbonate, methylcyclohexanone, and γ-butyrolactone. The solvent for component (C) may be used alone or in combination of two or more. Toluene or cyclohexanone may be used as the solvent for component (C), with cyclohexanone being preferred from the viewpoint of toxicity. The resin composition can be used as a varnish by dissolving or dispersing component (A) and component (B) in a solvent for component (C). A varnish made from a resin composition containing component (A), component (B), and component (C) preferably has the first and second viscosities described above. Furthermore, a varnish made from a resin composition containing component (A), component (B), and component (C) preferably has the thixotropy index TI described above.

[0052] The content of component (C) in the resin composition is preferably within a range of 20 to 90% by mass, or may be within a range of 30 to 86% by mass, 40 to 84% by mass, or 50 to 82% by mass, relative to 100% by mass of the total amount of components (A), (B), and (C). When the content of component (C) is within a range of 20 to 90% by mass, relative to 100% by mass of the total amount of components (A), (B), and (C), components (A) and (B) are easily dissolved or dispersed in component (C), and when the resin composition is applied to a semiconductor substrate using, for example, a spin coater, a coating film of approximately uniform thickness with little variation in thickness can be formed, and the component is less likely to remain in the coating film, thereby suppressing deterioration of the dielectric properties.

[0053] Component (C) can be a commercially available product, such as toluene (toluene concentration 100% by mass, manufactured by Taishin Chemical Co., Ltd.) or anone (cyclohexanone) (cyclohexanone concentration 90 to 100% by mass, manufactured by Taishin Chemical Co., Ltd.).

[0054] The resin composition is sufficient as long as it contains component (A) and component (B), and may contain component (C), or may contain components other than component (A), component (B), and component (C), or may not contain components other than component (A), component (B), and component (C). The resin composition may consist of only component (A), component (B), and component (C).

[0055] The resin composition may contain a coupling agent to improve adhesion to the semiconductor substrate. The resin composition may also contain an organic peroxide to improve reactivity. The resin composition may also contain at least one additive selected from the group consisting of organic peroxides, coupling agents, ion trapping agents, leveling agents, antioxidants, viscosity modifiers, and flame retardants. The coupling agent is a compound having two or more different functional groups in one molecule, one of which is a functional group that chemically bonds with inorganic materials and the other is a functional group that chemically bonds with organic materials. Examples of coupling agents include at least one selected from the group consisting of silane coupling agents, aluminum coupling agents, and titanium coupling agents, and may also be a silane coupling agent. One type of coupling agent may be used, or two or more types may be used in combination. Examples of functional groups possessed by silane coupling agents include alkoxy groups, vinyl groups, epoxy groups, styryl groups, methacrylic groups, acrylic groups, amino groups, isocyanurate groups, ureido groups, mercapto groups, sulfide groups, and isocyanate groups.

[0056] The resin composition may contain an organic peroxide that initiates a radical polymerization reaction, taking into consideration the reactivity of components (A) and (B). Examples of the organic peroxide that can be used include peroxycarbonate. Perbutyl (trademark) Z manufactured by NOF Corporation can be used as the peroxycarbonate.

[0057] The content of the additive contained in the resin composition may be 10.0% by mass or less, 8.0% by mass or less, or 5.0% by mass or less, relative to 100% by mass of the resin composition. The content of the additive contained in the resin composition may be 0.10% by mass or more, 0.20% by mass or more, 0.30% by mass or more, or 0.50% by mass or more. The additive may be a commercially available product. When the additive is a silane coupling agent, for example, 3-methacryloxypropyltrimethoxysilane KBM 503, vinyltrimethoxysilane KBM 1003 (manufactured by Shin-Etsu Silicones Co., Ltd.), or Coatsil MP200 Silane (manufactured by Momentive Performance Materials Japan) may be used.

[0058] The resin composition is a non-photosensitive resin composition for wafer-level chip-size package semiconductor devices. The resin composition preferably does not contain inorganic fillers such as silica. When a thermosetting insulating resin is used to form an interlayer insulating film, a subsequent process involves drilling the interlayer insulating film with laser irradiation to form via holes for wiring. If the interlayer insulating film contains an inorganic filler such as silica, the silica portion may not be properly removed during laser processing, which may make it difficult to properly copper-plate the via holes. Therefore, it is preferable that the resin composition does not contain inorganic fillers such as silica. Here, "not containing inorganic fillers such as silica" means that no inorganic fillers are intentionally added to the resin composition. The resin composition may contain inorganic materials in a range of 0.0001% by mass to 0.01% by mass, or 0% by mass, based on 100% by mass of the resin composition.

[0059] Method for Producing Resin Composition The resin composition can be produced by mixing component (A) and component (B), and optionally component (C). The resin composition may also be produced by mixing component (A) and component (B), and optionally component (C), together with additives as needed. However, adding fillers such as silicon dioxide or aluminum oxide is not preferred as this may deteriorate the coatability. Preferably, the resin composition does not contain silicon dioxide or aluminum oxide powder. The method for producing the resin composition is not particularly limited. The resin composition can be produced by mixing the raw materials for each component using a mixer such as a mortar and pestle mixer, a pot mill, a three-roll mill, a hybrid mixer, a rotary mixer, or a twin-screw mixer. These components may be mixed simultaneously, or some may be mixed first and the rest may be mixed later. The resin composition may also be produced using an appropriate combination of the above devices.

[0060] The cured product obtained by curing the resin composition preferably has a relative dielectric constant (ε) of 3.0 or less, more preferably 2.8 or less, and even more preferably 2.7 or less. The dielectric dissipation factor (tanδ) is preferably 0.015 or less, more preferably 0.014 or less, and even more preferably 0.013 or less. Cured products with low dielectric constants and low dielectric dissipation factors have good electrical properties when used in high-frequency regions, and can therefore be used in electronic components, semiconductor devices, and the like used in high-frequency regions. Furthermore, when the resin composition is applied to a semiconductor substrate using, for example, a spin coater, it cures sufficiently to produce a thin-film cured product with a substantially uniform thickness that has good electrical properties even when used in high-frequency regions, such as in the fifth-generation communication system "5G," which is expected to see increased capacity and faster communication. Therefore, the resin composition can be suitably used as a material for forming an interlayer insulating film that seals the side of the semiconductor substrate where the electrodes and wiring are located, in a semiconductor device including a semiconductor substrate, electrodes arranged on the semiconductor substrate, wiring connected to the electrodes, external terminals electrically connected via the wiring, and an interlayer insulating film. This interlayer insulating film is disposed so as to contact the wiring. In this specification, the term "rewiring layer" includes wiring and an interlayer insulating film. In the literature, "wiring" is sometimes referred to as "rewiring layer," and "interlayer insulating film" is sometimes referred to as "encapsulating resin layer." Furthermore, the resin composition can be suitably used as a material for forming an interlayer insulating film that encapsulates the semiconductor substrate side of the wiring and the opposite side of the wiring from the semiconductor substrate in a semiconductor device. The thickness of the rewiring layer can be approximately 5 to 30 μm. The thickness of the rewiring layer may be 5 μm or more, or 10 μm or more. The thickness of the rewiring layer may be 30 μm or less, or 20 μm or less.

[0061] The resin composition can be suitably used as a sealing resin for WL-CSP type semiconductor devices.

[0062] Next, a WL-CSP type semiconductor device using a resin composition will be described. The WL-CSP type semiconductor device includes a semiconductor substrate, electrodes disposed on the semiconductor substrate, wiring connected to the electrodes, external terminals electrically connected via the wiring, and an interlayer insulating film that seals the side of the semiconductor substrate on which the electrodes and wiring are disposed. The interlayer insulating film is formed using a resin composition containing the aforementioned components (A), (B), and (C). A WL-CSP type semiconductor device having an interlayer insulating film disposed in contact with the wiring preferably includes at least two layers: a first interlayer insulating film (also referred to as a "dielectric film") that seals the semiconductor substrate side of the wiring, and a second interlayer insulating film that seals the opposite side of the wiring from the semiconductor substrate. Both the first interlayer insulating film (dielectric film) and the second interlayer insulating film are disposed in contact with the wiring and function as interlayer insulating films for the wiring.

[0063] A WL-CSP type semiconductor device will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing the schematic configuration of a WL-CSP type semiconductor device. The WL-CSP type semiconductor device is not limited to the example shown in Fig. 1.

[0064] A WL-CSP type semiconductor device 10 includes, on a semiconductor substrate 1, an electrode 2, a wiring 4 connected to the electrode 2, and an external connection terminal 8 such as a conductive ball electrically connected to the wiring 4. A protective layer 3 made of an oxide film or the like may be formed between the wiring 4 and the semiconductor substrate 1. The WL-CSP type semiconductor device 10 includes interlayer insulating films 5 and 6 that seal the side of the semiconductor substrate 1 on which the electrode 2 and wiring 4 are disposed. The interlayer insulating films 5 and 6 are disposed so as to contact the wiring 4. The film that seals the semiconductor substrate 1 side of the wiring 4 is a first interlayer insulating film (dielectric film) 5. The film that seals the side of the wiring 4 opposite the semiconductor substrate 1 side is a second interlayer insulating film 6. The interlayer insulating films 5 and 6 may include at least two layers. Both the first interlayer insulating film (dielectric layer) 5 and the second interlayer insulating film 6 are disposed so as to contact the wiring 4. By using the same resin composition for the first interlayer insulating film 5 and the second interlayer insulating film 6, the dielectric properties can be lowered and the electrical properties can be improved when used in a high frequency range. The wiring 4, the first interlayer insulating film (dielectric film) 5, and the second interlayer insulating film 6 constitute a rewiring layer 7.

[0065] Manufacturing Method of Semiconductor Device Next, a manufacturing method of a WL-CSP type semiconductor device will be described. Unless otherwise specified, the semiconductor device will refer to a WL-CSP type semiconductor device. The semiconductor substrate can be made of a material such as silicon, SiGe, or SOI. The electrodes can be formed by forming a film of electrode material over substantially the entire surface of the semiconductor substrate by, for example, vacuum deposition or sputtering, and then patterning the film by, for example, photolithography, to form multiple electrodes at predetermined positions on the semiconductor substrate.

[0066] After forming an electrode on the surface of the semiconductor substrate, a silicon nitride (SiN) film is formed over the entire surface of the semiconductor substrate by, for example, vapor deposition, and an oxide film (passivation film) is further formed on the surface of the silicon nitride to form a protective layer. The thicknesses of the semiconductor substrate, electrode, and protective layer are not particularly limited.

[0067] Next, the resin composition is dropped onto the semiconductor substrate, the semiconductor substrate is rotated around a vertical axis using a spin coater to apply the liquid resin composition onto the semiconductor substrate, and the liquid resin composition is cured to form an interlayer insulating film. Specifically, the resin composition is dropped onto the electrodes and protective layer on the semiconductor substrate, the semiconductor substrate is rotated around a vertical axis using a spin coater to apply the liquid resin composition onto the electrodes and protective layer on the semiconductor substrate, and the liquid resin composition is cured to form a first interlayer insulating film (dielectric film).

[0068] When applying the resin composition to form an interlayer insulating film, the rotation speed of the spin coater is preferably 1000 rpm to 3000 rpm, and the rotation time is preferably 5 seconds to 30 seconds. If the rotation speed and rotation time of the spin coater are within the above ranges, the resin composition can be applied to a semiconductor substrate with a substantially uniform thickness, an interlayer insulating film having a desired substantially uniform thickness after curing can be formed, and warping of the semiconductor substrate during curing can be suppressed.

[0069] The interlayer insulating film can be formed using a resin composition containing the aforementioned components (A) and (B), and optionally containing component (C). By using the aforementioned resin composition, even when the resin composition is applied to a semiconductor substrate using a spin coater, a coating film of approximately uniform thickness can be formed with little variation in thickness, and a first interlayer insulating film (dielectric film) can be formed that suppresses warping of the semiconductor substrate upon curing. The resin composition containing the aforementioned components (A) and (B), and optionally containing component (C), can be used to form a correlation insulating film. The interlayer insulating film may be either a first interlayer insulating film (dielectric film) or a second interlayer insulating film. The aforementioned component (A) preferably contains a modified PPE resin represented by formula (1), and component (A) preferably contains at least one selected from the group consisting of a modified PPE resin represented by formula (5) and a modified PPE resin represented by formula (6). The aforementioned component (B) preferably contains at least one selected from the group consisting of an SBS represented by formula (7) and an NBR represented by formula (8).

[0070] The rotation speed of the spin coater is preferably 1000 rpm to 3000 rpm, and the rotation time is preferably 5 seconds to 30 seconds.

[0071] When applied to a semiconductor substrate using a spin coater, the resin composition preferably has a first viscosity of 300 mPa·s to 4000 mPa·s, more preferably 400 mPa·s to 4000 mPa·s, and even more preferably 500 mPa·s to 2000 mPa·s, as measured with a rotational viscometer at 25°C and 10 rpm. If the first viscosity of the resin composition when applied to a semiconductor substrate using a spin coater is within the above range, a coating film with little thickness variation and a substantially uniform thickness can be formed, and warping of the semiconductor substrate during curing can be suppressed.

[0072] When applied to a semiconductor substrate using a spin coater, the resin composition preferably has a second viscosity at 25°C and 1 rpm measured with a rotational viscometer in the range of 500 mPa·s to 4200 mPa·s, more preferably in the range of 550 mPa·s to 4200 mPa·s, even more preferably in the range of 550 mPa·s to 4000 mPa·s, and even more preferably in the range of 550 mPa·s to 3500 mPa·s. If the second viscosity of the resin composition when applied to a semiconductor substrate using a spin coater is within the above range, a coating film with little thickness variation and a substantially uniform thickness can be formed, and warping of the semiconductor substrate during curing can be suppressed.

[0073] When the resin composition is applied to a semiconductor substrate using a spin coater, the thixotropy index TI, which is the ratio of the second viscosity to the first viscosity, is preferably in the range of 0.8 to 1.2, or may be in the range of 0.9 to 1.1, or may be in the range of 1.0 to 1.1. If the second viscosity relative to the first viscosity of the resin composition when applied to a semiconductor substrate using a spin coater is within the above range, a coating film with little thickness variation and a substantially uniform thickness can be formed, and warping of the semiconductor substrate during curing can be suppressed.

[0074] The thickness of each of the interlayer insulating film, the first interlayer insulating film (dielectric film), and the second interlayer insulating film is preferably in the range of 3 μm to 20 μm, and may be in the range of 4 μm to 18 μm, or may be in the range of 5 μm to 17 μm. As long as the thickness of each of the interlayer insulating film, the first interlayer insulating film (dielectric film), and the second interlayer insulating film is in the range of 3 μm to 20 μm, the demand for miniaturization and thinning of semiconductor devices can be satisfied even when multiple films are stacked.

[0075] In the method for manufacturing a semiconductor device, after the resin composition is applied, it is dried and cured, and then a first interlayer insulating film (dielectric film) having openings on the surface portions of the electrodes can be formed by laser direct patterning, for example, using a laser direct patterning device (manufactured by Mitsubishi Electric Corporation).

[0076] Next, a seed layer for forming wiring is formed on substantially the entire surface of the semiconductor substrate on which the electrodes, protective layer, and first interlayer insulating film (dielectric film) have been formed, using deposition, sputtering, chemical vapor deposition (CVD), electroless plating, or the like. The seed layer may contain copper, copper oxide, an alloy of copper and chromium, copper, tantalum, cobalt, titanium, and alloys thereof. The seed layer may also have a laminate structure in which multiple layers are stacked. A resist is formed on this seed layer in a predetermined pattern, for example, by photolithography, and wiring of the predetermined pattern is formed by electroplating or electroless plating using this resist film as a mask. After the wiring is formed, the resist film is peeled off, and the seed layer remaining in the non-wiring regions is removed by etching or the like. The thickness of the wiring is not particularly limited, but may be 0.1 μm or more, 15 μm or less, 12 μm or less, or 10 μm or less.

[0077] Next, the resin composition is applied to the wiring using a spin coater so that the surface height is approximately uniform, forming a second interlayer insulating film. The second interlayer insulating film can be a resin composition containing the aforementioned components (A), (B), and (C), similar to the first interlayer insulating film. It can be applied to the semiconductor substrate, specifically, to the wiring, using a spin coater with the same rotation speed and rotation time as the first interlayer insulating film. After the resin composition is applied, it is dried and cured, and then a second interlayer insulating film can be formed by laser direct patterning, for example, using a laser direct patterning device (manufactured by Mitsubishi Electric Corporation), with openings in the surface portions of the wiring where the external terminals described below will be located. The second interlayer insulating film may also be formed by openings in the surface portions of the electrodes by exposure and development.

[0078] In some cases, the formation of a rewiring layer may be a combination of the formation of a first interlayer insulating film (dielectric film), the formation of wiring, and the formation of a second interlayer insulating film.

[0079] Thereafter, external terminals such as solder balls are formed in the openings of the rewiring layer by a solder ball mounting method, a solder plating method, a solder paste method, a solder paste dispensing method, a solder vapor deposition method, or the like, thereby forming a WL-CSP type semiconductor device. The WL-CSP type semiconductor device formed in this manner has a first interlayer insulating film and a second interlayer insulating film made using a resin composition containing the aforementioned components (A), (B), and (C), and therefore has a low dielectric constant and a low dielectric loss tangent, and exhibits good electrical characteristics even when the semiconductor device is used in a high-frequency range such as the fifth-generation communication system "5G," which is expected to increase capacity and speed of communication.

[0080] The resin composition according to the embodiment of the present invention and the semiconductor device using the same can be used in electronic components of electronic devices such as mobile phones, smartphones, notebook computers, tablet terminals, and camera modules.

[0081] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. In the following examples and comparative examples, the numbers indicating the blending ratio of each component contained in the resin composition represent the ratio (mass (%)) when the total amount of the resin composition is 100 mass %, unless otherwise specified. When the resin composition contains only components (A), (B), and (C) and does not contain additives, the total amount of the resin composition represents the sum of the amounts of components (A), (B), and (C).

[0082] Component (A): Modified polyphenylene ether (PPE) resin A-1: ​​OPE 2st 1200 (modified polyphenylene ether resin represented by formula (6) having vinyl groups at both ends (reaction product of 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diol / 2,6-dimethylphenol condensate and chloromethylstyrene), number average molecular weight (Mn) 1200) (manufactured by Mitsubishi Gas Chemical Company, Inc.) A-2: OPE 2st 2200 (modified polyphenylene ether resin represented by formula (6) having vinyl groups at both ends (reaction product of 2,2',3,3',5,5'-hexamethylbiphenyl-4,4'-diol / 2,6-dimethylphenol condensate and chloromethylstyrene), number average molecular weight (Mn) 2200) (manufactured by Mitsubishi Gas Chemical Company, Inc.) A-3: NORYL SA9000 (a modified polyphenylene ether resin represented by formula (5) having a group represented by formula (3) at its terminal, and having methacryloyl groups at both terminals, number average molecular weight (Mn) of 1850 to 1950 (manufactured by SABIC Innovative Plastics)

[0083] Component (B): Unhydrogenated styrene / butadiene / styrene block copolymer (SBS) B-1: Styrene / butadiene / styrene block copolymer (SBS) TR2827, styrene / butadiene ratio 24 / 76 (%), number average molecular weight (Mn) 130,000 (manufactured by JSR Corporation). B-2: Styrene / butadiene / styrene block copolymer (SBS) TR2003, styrene / butadiene ratio 43 / 57 (%), number average molecular weight (Mn) 100,000 (manufactured by JSR Corporation). B-3: Styrene / butadiene / styrene block copolymer (SBS) TR2250, styrene / butadiene ratio 52 / 48 (%), number average molecular weight (Mn) 100,000 (manufactured by JSR Corporation). B-4: Partially hydrogenated styrene / butadiene / butylene / styrene block copolymer (SBBS) P5051, styrene / butadiene ratio 47 / 53 (%), number average molecular weight (Mn) 53,000 (manufactured by Asahi Kasei Chemicals Corporation). B-5: Carboxylated carboxylated nitrilobutadiene rubber (NBR) Nipol™ 1072, number average molecular weight (Mn) 500,000 (manufactured by Zeon Corporation).

[0084] Component (B'): tetrafluoroethylene resin B'-6: tetrafluoroethylene resin Lubron (registered trademark) L-5F (manufactured by Daikin Industries, Ltd.).

[0085] Component (C): Solvent C-1: Toluene (manufactured by Taishin Chemical Co., Ltd.), boiling point: 110.6°C. C-2: Anone (cyclohexanenone, manufactured by Taishin Chemical Co., Ltd.), boiling point: 155.65°C.

[0086] Additive: Organic peroxide Perbutyl (registered trademark) Z (NOF Corporation)

[0087] Examples 1 to 12, Comparative Example 1 Component (A), component (B) or component (B'), and component (C) were mixed and dissolved using a stirrer (SSR-112, manufactured by AGC Technoglass Co., Ltd.) at a constant temperature of 70°C in a thermostatic water bath (SB-35, manufactured by Tokyo Rikakikai Co., Ltd.) to produce each resin composition of the Examples and Comparative Examples. In Table 1, the symbol "-" indicates that the corresponding component is not contained in the resin composition. Also, in Table 1, "Mn" represents the number average molecular weight.

[0088]

[0089] Evaluation of Resin Compositions The solubility and viscosity of each resin composition of the Examples and Comparative Examples were measured, and the results are shown in Table 3. In Table 3, for Comparative Example 1 in which component (B') was not soluble in the solvent of component (C), a coating film could not be formed, and therefore evaluation could not be performed, and this was recorded as NA (Not Available).

[0090] For each resin composition, the solubility of component (A) and component (B) or component (B') was evaluated by heating the solvent for component (C) to 70° C. Resin compositions in which it was clear by visual inspection that component (A) and component (B) or component (B') had dissolved in the solvent for component (C) were rated G (good), and resin compositions in which it was clear by visual inspection that they had not dissolved were rated N (not-good).

[0091] Viscosity For each resin composition, a first viscosity at 25°C and 10 rpm and a second viscosity at 25°C and 1 rpm were measured using a TVE type viscometer (cone rotor: 1°34' x R24, manufactured by Toki Sangyo Co., Ltd.), and the thixotropy index TI (viscosity at 1 rpm / viscosity at 10 rpm) of the second viscosity relative to the first viscosity was measured.

[0092] Formation of Interlayer Insulating Films Using each of the resin compositions of the Examples and Comparative Examples, coating films serving as interlayer insulating films were formed. The coating films of the resin compositions were then heat-treated under the following conditions to harden them. The cured products were then evaluated as follows. The results are shown in Table 3. Thickness of Interlayer Insulating Films by Spin Coating: Each of the resin compositions of the Examples and Comparative Examples was spin-coated onto a silicon wafer having a diameter of 150 mm and a thickness of 0.525 mm as a semiconductor substrate using a spin coater (MS-A200, manufactured by Mikasa Co., Ltd.). The spin coater was operated at 1000 rpm for 5 seconds, then at 2000 rpm for 30 seconds to spin-coat the resin composition onto the silicon wafer surface, forming a coating film. Furthermore, each of the resin compositions of the Examples and Comparative Examples was spin-coated onto a silicon wafer having a diameter of 150 mm and a thickness of 0.525 mm as a semiconductor substrate using a spin coater (MS-A200, manufactured by Mikasa Co., Ltd.). The spin coater was operated at 1000 rpm for 5 seconds, then at 3000 rpm for 30 seconds to spin coat the resin composition onto the silicon wafer surface and form a coating film. Next, the silicon wafer with the thin film of the resin composition was pre-heat-treated (dried) at 130°C for 10 minutes under a nitrogen atmosphere and heated to dry the resin composition coating film, thereby obtaining a sample. This was then heat-treated (cured) at 200°C for 60 minutes under a nitrogen atmosphere to obtain a sample in which the resin composition coating film was cured. The thickness of the resin composition coating film was measured using a stylus profiling system (Surfcom 300B, manufactured by Tokyo Seimitsu Co., Ltd.). The thickness of the interlayer insulating film can be approximately 5 μm to 30 μm. The thickness of the interlayer insulating film may be 5 μm or more, or 10 μm or more. The thickness of the interlayer insulating film may be 30 μm or less, or 20 μm or less.

[0093] Warpage of Semiconductor Substrate The warpage of a 150 mm diameter, 0.525 mm thick silicon wafer (before coating) was measured using a 3D heating surface profiler (Thermoray AXP2.0, manufactured by Akrometrix) as the semiconductor substrate (hereinafter referred to as "initial warpage"). 3 g of the resin composition was dropped onto the center of the silicon wafer, and each resin composition of the Examples and Comparative Examples was spin-coated using a spin coater (MS-A200, manufactured by Mikasa Co., Ltd.). The spin coater was operated to spin-coat the resin composition onto the silicon wafer surface to form a coating film. Next, the silicon wafer with a thin film of the resin composition was pre-heat-treated (dried) at 130°C for 10 minutes under a nitrogen atmosphere, and then heated to obtain a sample in which the coating film of the resin composition was dried. Subsequently, a heat treatment (curing) was performed at 200°C for 60 minutes under a nitrogen atmosphere to obtain a sample in which the coating film of the resin composition was cured. Next, the warpage of the silicon wafer was measured using a 3D heating surface profiler (Thermoray AXP2.0, manufactured by Akrometrix) (hereinafter referred to as "post-cure warpage"). The warpage refers to the value (height) obtained by subtracting the initial warpage from the "post-cure warpage." Hereinafter, the silicon wafer will also be referred to simply as "wafer." Warpage = (post-cure warpage) - (initial warpage). The warpage is preferably within the range of -5 mm to 5 mm, more preferably within the range of -3 mm to 3 mm, and even more preferably within the range of -2 mm to 2 mm. When the warpage is within the range of -5 mm to 5 mm, the wafer can be suction-held using a wafer holder (e.g., vacuum tweezers) with a vacuum suction mechanism, and the wafer can be moved to the desired position by moving the wafer holder. However, if the wafer has a large warpage, it will be impossible to suction the entire wafer, and only the central portion of the wafer will be partially suctioned, for example. In this case, sufficient holding force cannot be obtained, and even a slight shock during wafer transfer may cause the wafer to come off the vacuum tweezers and fall. If the holding force becomes extremely weak, it may become impossible to hold the wafer.

[0094] Strength (Adhesion) Measurement (Cross-Cut Peel Test) Strength (adhesion) was measured in accordance with ASTM D3359-97. Specifically, each resin composition of the Examples and Comparative Examples was spin-coated onto a semiconductor substrate using a silicon wafer spin coater (MS-A200, manufactured by Mikasa Co., Ltd.) with a diameter of 150 mm and a thickness of 0.525 mm. The spin coating was performed by operating the spin coater to spin-coat the resin composition onto the silicon wafer surface to form a coating film. Next, the silicon wafer having a thin film of the resin composition was pre-heat-treated (dried) at 130°C for 10 minutes under a nitrogen atmosphere, and then heated to obtain a sample in which the coating film of the resin composition was dried. Subsequently, a heat treatment (curing) was performed at 200°C for 60 minutes under a nitrogen atmosphere to obtain a sample in which the coating film of the resin composition was cured. In this manner, samples for the cross-cut peel test were prepared. Using a cross-cut guide (manufactured by Gotec Co., Ltd.), cuts were made in a grid pattern on the surface of the specimen bearing the coating film that had been prepared to function as an interlayer insulating film, and then cellophane tape (manufactured by Nichiban Co., Ltd.) was applied to the intersecting cuts, which were then quickly peeled off. The area of ​​the peeled coating was measured and rated on a scale of 0B to 5B, as shown in Table 2 below.

[0095]

[0096] Measurement samples for dielectric constant (ε) and dielectric loss tangent (tanδ) were prepared as follows. Each resin composition of the Examples and Comparative Examples was applied to a polyethylene terephthalate (PET) support, pre-heat-treated (dried) at 130°C for 10 minutes in a nitrogen atmosphere, heated to dry the resin composition, and then cured at 200°C for 60 minutes in a nitrogen atmosphere to obtain a coating film made of the resin composition with a thickness of 10 μm. The dielectric constant (ε) and dielectric loss tangent (tanδ) of the measurement sample were measured using a cavity resonator perturbation method at a dielectric resonance frequency of 5 GHz. The dielectric constant (ε) is preferably 1.5 to 3.0, and the dielectric loss tangent (tanδ) is preferably 0.001 to 0.010.

[0097]

[0098] As shown in Tables 1 and 3, the resin compositions of Examples 1 to 12 had good solubility of component (A) and component (B) in component (C), and were able to form coating films of approximately uniform thickness when applied to semiconductor substrates using a spin coater. Furthermore, the coating films obtained from the resin compositions of Examples 1 to 12 had a relative dielectric constant (ε) of 2.7 or less and a dielectric loss tangent (tanδ) of 0.015 or less, and exhibited good electrical properties even when semiconductor devices were used in high-frequency regions, such as the fifth-generation communication system "5G," which is expected to see increased capacity and faster communication.

[0099] Furthermore, as shown in Tables 1 and 3, the resin compositions of Examples 1 to 12 had a first viscosity at 25°C and 10 rpm in the range of 300 mPa·s to 4000 mPa·s, a second viscosity at 25°C and 1 rpm in the range of 500 mPa·s to 4200 mPa·s, and a thixotropy index TI, which is the ratio of the second viscosity to the first viscosity, in the range of 0.8 to 1.2. The resin compositions of Examples 1 to 9 were able to form coatings of substantially uniform thickness with little variation even when applied to semiconductor substrates using a spin coater, and were able to suppress warping of the semiconductor substrate during curing. Furthermore, the resin compositions of Examples 1 to 12 were rated 5B in a cross-cut peel test, meaning that the removed area was 0%, and also had good adhesion.

[0100] In the resin composition containing tetrafluoroethylene resin in Comparative Example 1, the SEBS or tetrafluoroethylene resin was not soluble in the solvent of component (C), and the resin composition could not be applied to a semiconductor substrate, and a coating film could not be formed.

[0101] The resin composition according to the present invention can be used in a WL-CSP type semiconductor device. The resin composition according to an embodiment of the present invention and a semiconductor device using the same can be used as electronic components for electronic devices such as mobile phones, smartphones, laptop computers, tablet terminals, and camera modules.

[0102] 1: semiconductor substrate, 2: electrode, 3: protective layer, 4: wiring, 5: first interlayer insulating film (dielectric), 6: second interlayer insulating film, 7: rewiring layer, 8: external terminal, 10: semiconductor device.

Claims

1. (A) a modified polyphenylene ether resin having an unsaturated double bond at a terminal thereof, and (B) A resin composition for use in a wafer-level chip size package type semiconductor device, comprising an elastomer having a butadiene skeleton.

2. The modified polyphenylene ether resin (A) having an unsaturated double bond at a terminal thereof is represented by the following formula (1): 【Chemistry 20】 [In formula (1), X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, Y is represented by the following formula (2): 【Chemistry 21】 [In formula (2), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkenylcarbonyl group. represents an unsubstituted or substituted phenol repeating unit represented by the formula: Z represents a functional group containing a terminal carbon-carbon double bond, and is a vinyl group, a vinylene group, or a group represented by the following formula (3): 【Chemical 22】 [In formula (3), R ５ represents a hydrogen atom or an alkyl group. or a (meth)acryloyl group represented by the following formula (4): 【Chemistry 23】 [In formula (4), R ６ ~R ８ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. represents a styrene group represented by the formula: m represents an integer from 1 to 100; n represents 0 or an integer from 1 to 6; p represents an integer of 1 to 4. The resin composition according to claim 1 , comprising a modified polyphenylene ether resin represented by the formula:

3. 2. The resin composition according to claim 1, wherein the (B) elastomer having a butadiene skeleton includes at least one selected from the group consisting of a styrene / butadiene / styrene copolymer, a styrene / butadiene / butylene / styrene copolymer, a butadiene polymer, a styrene / butadiene copolymer, and an acrylonitrile / butadiene copolymer.

4. The modified polyphenylene ether resin (A) having an unsaturated double bond at a terminal thereof is represented by the following formula (5): 【Chemistry 24】 [In formula (5), R ５ represents a hydrogen atom or an alkyl group, X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group; Y is represented by the following formula (2): 【Chemistry 25】 [In formula (2), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkenylcarbonyl group. represents an unsubstituted or substituted phenol repeating unit represented by the formula: m represents an integer from 1 to 100; n represents 0 or an integer from 1 to 6; p represents an integer of 1 to 4. and a modified polyphenylene ether resin represented by the following formula (6): 【Chemistry 26】 [In formula (6), R ６ ~R ８ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group; Y represents an unsubstituted or substituted phenol repeating unit represented by formula (2), m represents an integer from 1 to 100; n represents 0 or an integer from 1 to 6; p represents an integer of 1 to 4. The resin composition according to claim 1, comprising at least one modified polyphenylene ether resin selected from the group consisting of modified polyphenylene ether resins represented by the formula:

5. The (B) elastomer having a butadiene skeleton is represented by the following formula (7): 【Chemical 27】 [In formula (7), q and r each represent an integer of 0 to 1, at least one of which is not 0, s represents an integer of 1 to 1200, and t represents an integer of 1 to 1000.] and a styrene / butadiene / styrene block copolymer represented by the following formula (8): 【Chemistry 28】 [In formula (8), u represents an integer of 1 to 1200, and v represents an integer of 1 to 1000.] The resin composition according to claim 1, comprising at least one selected from the group consisting of acrylonitrile / butadiene copolymers represented by the formula:

6. The modified polyphenylene ether resin (A) having an unsaturated double bond at a terminal thereof is represented by the following formula (6): 【Chemical 29】 [In formula (6), R ６ ~R ８ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group; Y is represented by the following formula (2): 【Chemistry 30】 [In formula (2), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkenylcarbonyl group. represents an unsubstituted or substituted phenol repeating unit represented by the formula: m represents an integer from 1 to 100; n represents 0 or an integer from 1 to 6; p represents an integer of 1 to 4. The modified polyphenylene ether resin is represented by the formula: The resin composition according to claim 1 , wherein the (B) elastomer having a butadiene skeleton includes a styrene / butadiene / styrene copolymer.

7. The resin composition according to claim 1 , further comprising a solvent (C).

8. The resin composition according to claim 7, wherein the first viscosity at 25 ° C. and 10 rpm is in the range of 300 mPa · s to 4000 mPa · s using a rotational viscometer.

9. The resin composition according to claim 8, wherein the second viscosity at 25 ° C. and 1 rpm is in the range of 500 mPa s to 4200 mPa s using a rotational viscometer, and the thixotropy index TI, which is the ratio of the second viscosity to the first viscosity, is 0.8 to 1.

2.

10. The resin composition according to claim 1, wherein the mass ratio of the component (A) to the component (B) is within the range of 10:90 to 80:

20.

11. The resin composition according to claim 7, wherein the mass ratio of the total amount of the component (A) and the component (B) to the component (C) is within the range of 5:95 to 80:

20.

12. a semiconductor substrate; an electrode disposed on the semiconductor substrate; wiring electrically connected to the electrode; an external terminal electrically connected to the electrode via the wiring; and an interlayer insulating film sealing a side of the semiconductor substrate on which the electrode and the wiring are disposed; A wafer-level chip size package type semiconductor device, comprising: the interlayer insulating film disposed so as to be in contact with the wiring; and the resin composition according to claim 1 .

13. 13. The semiconductor device according to claim 12, further comprising at least two layers: a first interlayer insulating film sealing a side of said wiring that faces said semiconductor substrate; and a second interlayer insulating film sealing a side of said wiring that faces an opposite side of said semiconductor substrate.

14. 13. The semiconductor device according to claim 12, wherein the thickness of one of said interlayer insulating film, said first interlayer insulating film or said second interlayer insulating film is within a range of 3 [mu]m to 20 [mu]m.

15. The following components (A) to (C): (A) a modified polyphenylene ether resin having an unsaturated double bond at a terminal thereof; (B) an elastomer having a butadiene skeleton, and (C) preparing a liquid resin composition including a solvent; Dropping the resin composition onto a semiconductor substrate and rotating the semiconductor substrate about a vertical axis using a spin coater to coat the semiconductor substrate with the liquid resin composition; and curing the liquid resin composition to form an interlayer insulating film.

16. 16. The method for manufacturing a semiconductor device according to claim 15, wherein the rotation speed of the spin coater is 1000 rpm to 3000 rpm, and the rotation time is 5 seconds to 30 seconds.

17. The method for manufacturing a semiconductor device according to claim 15, wherein the liquid resin composition has a first viscosity of 300 mPa·s to 4000 mPa·s at 25° C. and 10 rpm as measured by a rotational viscometer.

18. The method for manufacturing a semiconductor device according to claim 17, wherein the liquid composition has a second viscosity of 500 mPa·s to 4200 mPa·s at 25° C. and 1 rpm as measured by a rotational viscometer, and a thixotropy index TI, which is a ratio of the second viscosity to the first viscosity, of 0.8 to 1.

2.

19. The modified polyphenylene ether resin (A) having an unsaturated double bond at a terminal thereof is represented by the following formula (1): 【Chemistry 31】 [In formula (1), X represents a p-valent unsubstituted or substituted aromatic hydrocarbon group, Y is represented by the following formula (2): 【Chemistry 32】 [In formula (2), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an alkenylcarbonyl group. represents an unsubstituted or substituted phenol repeating unit represented by the formula: Z represents a functional group containing a terminal carbon-carbon double bond, and is a vinyl group, a vinylene group, or a group represented by the following formula (3): 【Chemical Formula 33】 [In formula (3), R ５ represents a hydrogen atom or an alkyl group. or a (meth)acryloyl group represented by the following formula (4): 【Chemical 34】 [In formula (4), R ６ ~R ８ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. represents a styrene group represented by the formula: m represents an integer from 1 to 100; n represents 0 or an integer from 1 to 6; p represents an integer of 1 to 4. The modified polyphenylene ether resin is represented by the formula:

19. The method for producing a semiconductor device according to claim 15, wherein the elastomer (B) having a butadiene skeleton includes at least one selected from the group consisting of a styrene / butadiene / styrene copolymer, a styrene / butadiene / butylene / styrene copolymer, a butadiene polymer, a styrene / butadiene copolymer, and an acrylonitrile / butadiene copolymer.

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