Method for manufacturing substrate material for semiconductor package, prepreg, and substrate material for semiconductor package

Abstract

To provide a substrate material for a semiconductor package which makes it possible to stably form fine wiring while suppressing variation of wiring widths.SOLUTION: Disclosed is a method for manufacturing a substrate material for a semiconductor package, which includes a process of increasing the temperature of a laminate having metal foil, one or more prepregs, and metal foil which are laminated in this order to heat-press temperature while pressurizing the laminate. The prepreg includes an inorganic fiber substrate and a thermosetting resin composition. The content of the thermosetting resin composition is 40 to 80 mass% based on the mass of the prepreg. In the process of increasing the temperature of the laminate to heat-press temperature while pressurizing the laminate, the laminate is heated under a condition that the lowest melt viscosity of the prepreg becomes 5000 Pa s or less.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a substrate material for a semiconductor package, a prepreg, and a substrate material for a semiconductor package. [Background technology]

[0002] In order to realize high-speed transmission and miniaturization of semiconductor devices, it is necessary to connect wiring substrates for semiconductor packages and semiconductor chips at high density. As wiring substrates for semiconductor packages, those having a structure that can connect different types of semiconductor chips in parallel using a fine wiring layer and a structure that can mount semiconductor chips with fine bumps have been proposed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-126978 [Patent Document 2] Japanese Patent Application Publication No. 8-198982 Summary of the Invention [Problem to be solved by the invention]

[0004] Wiring substrates for semiconductor packages, on which semiconductor chips are mounted, are often manufactured by forming wiring on an insulating substrate or copper foil of a substrate material for semiconductor packages. Substrate materials for semiconductor packages are generally manufactured by a method including heating and pressurizing a laminate including several laminated prepregs.

[0005] To achieve higher density, wiring substrates for semiconductor packages are often required to have fine wiring with widths of 10 μm or less. However, when forming such fine wiring, minute variations in the wiring width can become a significant problem.

[0006] One aspect of the present disclosure relates to a substrate material for semiconductor packages that enables stable formation of fine wiring while suppressing variations in wiring width. [Means for solving the problem]

[0007] One aspect of the present disclosure provides a method for producing a substrate material for a semiconductor package, the method comprising the steps of: raising the temperature of a laminate having a metal foil, one or more prepregs, and a metal foil laminated in this order to a heat-press temperature while applying pressure to the laminate; and heating the laminate at a temperature equal to or higher than the heat-press temperature while applying pressure to form a substrate material having an insulating substrate formed from the prepregs and the metal foils provided on both sides of the insulating substrate. The prepreg includes an inorganic fiber base material and a thermosetting resin composition impregnated into the inorganic fiber base material. The content of the thermosetting resin composition is 40 to 80 mass% based on the mass of the prepreg. In the step of raising the temperature of the laminate to the heat-press temperature while applying pressure to the laminate, the laminate is heated under heating conditions such that the minimum melt viscosity of the prepreg is 5000 Pa s or less.

[0008] In general, the minimum melt viscosity of a prepreg varies depending on heating conditions such as the heating rate. According to the findings of the present inventors, in the hot-press process for forming a substrate material, if a laminate containing a prepreg with a specific resin content is heated under conditions that result in the prepreg's minimum melt viscosity being 5000 Pa·s or less, a substrate material with extremely small thickness variation is formed. Furthermore, when wiring is formed using a substrate material with small thickness variation, the variation in wiring width is reduced compared to conventional methods.

[0009] Another aspect of the present disclosure relates to a prepreg including an inorganic fiber substrate and a thermosetting resin composition impregnated into the inorganic fiber substrate. The content of the thermosetting resin composition is 40 to 80 mass% based on the mass of the prepreg. The minimum melt viscosity of the prepreg measured at a heating rate of 4°C / min is 5000 Pa s or less.

[0010] By using the prepreg according to one aspect of the present disclosure in the above method, it is possible to easily produce a substrate material for a semiconductor package that enables the stable formation of fine wiring while suppressing variations in wiring width.

[0011] Yet another aspect of the present disclosure provides a substrate material for a semiconductor package, comprising an insulating substrate having an insulating resin layer and an inorganic fiber base material provided in the insulating resin layer, wherein the content of the insulating resin layer is 40 to 80 mass % based on the mass of the insulating substrate, and the standard deviation of the thickness of the substrate material is 4 μm or less.

[0012] The substrate material for a semiconductor package according to one aspect of the present disclosure has small variations in thickness, and therefore makes it possible to form wiring while suppressing variations in wiring width. [Effects of the Invention]

[0013] According to one aspect of the present disclosure, there is provided a substrate material for semiconductor packages that enables stable formation of fine wiring while suppressing variation in wiring width. Because the variation in wiring width is small, high-density fine wiring can be easily formed. Because the substrate material for semiconductor packages according to one aspect of the present disclosure has small variation in thickness, wiring for transmitting high-frequency signals can be easily formed. The substrate material for semiconductor packages according to one aspect of the present disclosure is also excellent in terms of reducing warpage. A wiring board formed from the substrate material for semiconductor packages according to one aspect of the present disclosure enables semiconductor chips having fine bumps to be mounted with high reliability and good productivity. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a prepreg. [Figure 2] 1A to 1C are cross-sectional views showing an example of a method for manufacturing a substrate material for a semiconductor package. [Figure 3] 1A to 1C are cross-sectional views showing an example of a method for manufacturing a substrate material for a semiconductor package. [Figure 4] 1 is a graph showing an example of measurement results of the melt viscosity of a prepreg. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention is not limited to the following examples.

[0016] Fig. 1 is a cross-sectional view showing an example of a prepreg. The prepreg 1 shown in Fig. 1 includes an inorganic fiber base material 11 and a thermosetting resin composition 12 impregnated into the inorganic fiber base material 11.

[0017] The inorganic fiber substrate 11 can be, for example, a woven or nonwoven fabric containing inorganic fibers. The inorganic fibers constituting the inorganic fiber substrate 11 may be glass fibers, carbon fibers, or a combination thereof. The inorganic fiber substrate 11 may be a glass cloth made of glass fibers. The proportion of glass fibers in the inorganic fibers constituting the inorganic fiber substrate may be 80 to 100 mass %, 90 to 100 mass %, 95 to 100 mass %, or 99 to 100 mass %. The glass fibers may be, for example, E-glass, S-glass, or quartz glass. The thickness of the inorganic fiber substrate 11 may be 0.01 to 0.20 μm.

[0018] The minimum melt viscosity of prepreg 1 measured at a heating rate of 4°C / min may be 5000 Pa·s or less. The minimum melt viscosity of prepreg 1 is the minimum melt viscosity (complex viscosity) measured when a prepreg test piece is sandwiched between two parallel plates with a diameter of 8 mm and heated from 20°C to 200°C or higher at a predetermined heating rate, and dynamic viscoelasticity measurements are performed in shear mode at a frequency of 10 Hz. The thickness of the test piece is 10 to 400 μm, and if necessary, the test piece is prepared by laminating two or more prepregs. For measurement, for example, a viscoelasticity measuring device, ARES (manufactured by Rheometrics Scientific F.E., Inc.), can be used. The minimum melt viscosity of prepreg 1 measured at a heating rate of 4°C / min may be 3000 Pa·s or less or 1000 Pa·s or more.

[0019] The temperature at which prepreg 1 exhibits its minimum melt viscosity may be 80°C or higher from the viewpoint of prepreg handleability, and 120°C or higher from the viewpoint of storage stability. The temperature at which prepreg 1 exhibits its minimum melt viscosity may be 200°C or lower from the viewpoint of productivity, and 180°C or lower from the viewpoint of reducing warpage. Therefore, the temperature at which prepreg 1 exhibits its minimum melt viscosity may be 120 to 180°C.

[0020] When the melt viscosity of prepreg 1 measured at a heating rate of 4°C / min decreases to 10,000 Pa·s at temperature T1 [°C] as the temperature of laminate 5 increases, and then rises to 10,000 Pa·s at temperature T2 [°C] after passing through the minimum melt viscosity, the difference between T1 and T2 may be 20°C or more, or 25°C or more, or may be 50°C or less, from the viewpoint of further suppressing variation in wiring width, etc.

[0021] When measured at a temperature rise rate of 4°C / min, the melt viscosity of prepreg 1 was 55 x 10 3 1000×10 Pa·s / min or faster 3 The melt viscosity may increase from the minimum melt viscosity to 1000×10 Pa·s. 3 This is the average rate of increase in melt viscosity per minute from the time when the melt viscosity reaches the minimum melt viscosity [Pa s] to the time when the melt viscosity reaches the minimum melt viscosity [Pa s]. 3 If the time required for the viscosity to rise to Pa·s is T minutes, the rate of increase in melt viscosity can be calculated using the following formula: Melt viscosity increase rate [Pa·s / min] = (1000×10 3 -Minimum melt viscosity) / T

[0022] From the viewpoint of further suppressing the variation in wiring width, the rate of increase in melt viscosity is set to 60×10 3 Pa·s / min or more, 65×10 3 Pa·s / min or more, 70×10 3 Pa·s / min or more, 75×10 3Pa·s / min or more, 80×10 3 Pa·s / min or more, 85×10 3 Pa·s / min or more, 90×10 3 Pa·s / min or more, 95×10 3 Pa·s / min or more, 100×10 3 Pa·s / min or more, 105×10 3 Pa·s / min or more, or 110×10 3 Pa s / min or more, and 200×10 3 Pa·s / min or less, 190×10 3 Pa·s / min or less, 180×10 3 Pa·s / min or less, 170×10 3 Pa·s / min or less, or 160×10 3 It may be less than Pa·s / min.

[0023] The content of the thermosetting resin composition 12 in the prepreg 1 may be 40 to 80 mass %. Using a prepreg containing 40 to 80 mass % of the thermosetting resin composition 12, a substrate material for a semiconductor package with little thickness variation can be easily produced by the method described below. The content of the thermosetting resin composition 12 can be adjusted, for example, by the amount of the curable resin composition applied depending on the thickness of the inorganic fiber substrate 11.

[0024] The content of thermosetting resin composition 12 in prepreg 1 can be determined, for example, by a method including dividing a cross-sectional photograph of prepreg 1 into a region of inorganic fiber substrate 11 and a region of thermosetting resin composition 12 by binarization processing and calculating the area of ​​each. In this case, the density of inorganic fiber substrate 11 and the density of thermosetting resin composition 12 may be considered to be the same.

[0025] The thermosetting resin composition 12 may contain an inorganic component in addition to the thermosetting resin component. The proportion of the resin component in the thermosetting resin composition 12 may be 20 to 100 mass% relative to the mass of the thermosetting resin composition 12, or may be 20 to 80 mass% from the viewpoint of reducing the linear expansion coefficient, 30 to 100 mass% from the viewpoint of reducing voids after lamination, or 40 to 100 mass% from the viewpoint of further improving the flatness of the substrate material. Thus, the proportion of the resin component in the thermosetting resin composition 12 may be 40 to 80 mass% relative to the mass of the thermosetting resin composition 12. In other words, the proportion of the resin component in the prepreg 1 may be 16 to 64 mass%.

[0026] The proportion of the resin component contained in the thermosetting resin composition 12 can be calculated by a method such as ash content measurement. Ash content measurement is a method of calculating the proportion of the resin component by carbonizing the resin component at high temperature.

[0027] In the thermosetting resin composition 12, components excluding inorganic components may be considered to be resin components. An example of an inorganic component is an inorganic filler. In the thermosetting resin composition 12, components excluding inorganic fillers may be considered to be resin components.

[0028] The minimum melt viscosity of the prepreg 1 can be controlled by the resin components. There are no particular limitations on the minimum melt viscosity, but it can be controlled by adjusting, for example, the ratio of the resin component to the inorganic component, the molecular weight and glass transition temperature of the high-molecular-weight component contained in the resin component, the type and blending ratio of the thermosetting resin, and the type and blending ratio of the curing accelerator.

[0029] In particular, the molecular weight and glass transition temperature of the high-molecular-weight component contained in the resin component, as well as the type and blending ratio of the curing accelerator, can significantly affect the behavior of the melt viscosity of the prepreg. For example, the glass transition temperature of the high-molecular-weight component may be lower than the temperature at which the curing reaction of the thermosetting resin composition is activated. The glass transition temperature of the high-molecular-weight component may be the temperature at which the maximum value of tan δ is obtained when the dynamic viscoelasticity of a strip-shaped molded product of the high-molecular-weight component is measured in a temperature range of 40 to 350°C under conditions of a chuck distance of 20 mm, a frequency of 10 Hz, and a heating rate of 5°C / min. A dynamic viscoelasticity measuring device manufactured by UBM, for example, can be used to measure the dynamic viscoelasticity. The temperature at which the curing reaction of the thermosetting resin composition is activated may be the temperature at which the maximum heat generation due to the curing reaction is obtained when differential scanning calorimetry of the thermosetting resin composition is performed in a temperature range of 40 to 350°C at a heating rate of 5°C / min. A differential scanning calorimeter manufactured by PerkinElmer, for example, can be used to measure the differential scanning calorimetry.

[0030] The glass transition temperature of the high molecular weight component may be 10 to 80°C lower than the temperature at which the curing reaction of the thermosetting resin composition is activated. From the viewpoint of reducing the influence of temperature variations when laminating the prepregs, the glass transition temperature of the high molecular weight component may be 20 to 80°C lower than the temperature at which the curing reaction of the thermosetting resin composition is activated. From the viewpoint of suppressing voids when laminating the prepregs, the glass transition temperature of the high molecular weight component may be 10 to 60°C lower than the temperature at which the curing reaction of the thermosetting resin composition is activated. Therefore, the glass transition temperature of the high molecular weight component may be 20 to 60°C lower than the temperature at which the curing reaction of the thermosetting resin composition is activated.

[0031] The thermosetting resin composition 12 may contain a thermoplastic resin as a high-molecular-weight component. The thermoplastic resin is not particularly limited as long as it is a resin that softens when heated, and may have one or more reactive functional groups at the molecular end or in the molecular chain. Examples of the reactive functional group include an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acryloyl group, a methacryloyl group, a vinyl group, and a maleic anhydride group.

[0032] The thermoplastic resin may be, for example, at least one selected from an acrylic resin, a polyamide resin, a polyimide resin, and a polyurethane resin.

[0033] The content of the thermoplastic resin may be, for example, 20 to 80 mass % based on the total mass of the components of the thermosetting resin composition 12 other than the inorganic filler.

[0034] To suppress moisture absorption, the thermoplastic resin may contain a resin having a siloxane group. For example, an acrylic resin, a polyamide resin, a polyimide resin, or a polyurethane resin may have a siloxane group. The resin having a siloxane group may be a silicone resin.

[0035] From the viewpoints of suppressing outgassing during heating and improving adhesiveness, the thermoplastic resin may contain a polyimide resin having a siloxane group, which may be, for example, a polymer formed by the reaction of a siloxane diamine with a tetracarboxylic dianhydride or a polymer formed by the reaction of a siloxane diamine with a bismaleimide.

[0036] The siloxane diamine may be, for example, a compound represented by the following general formula (5). [ka] In the formula, Q 4 and Q 9 each independently represents an alkylene group having 1 to 5 carbon atoms or a phenylene group which may have a substituent, and Q 5 , Q 6 , Q 7 and Q 8 each independently represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenoxy group; and d represents an integer of 1 to 5.

[0037] Examples of siloxane diamines represented by formula (5) where d is 1 include 1,1,3,3-tetramethyl-1,3-bis(4-aminophenyl)disiloxane, 1,1,3,3-tetraphenoxy-1,3-bis(4-aminoethyl)disiloxane, 1,1,3,3-tetraphenyl-1,3-bis(2-aminoethyl)disiloxane, and 1,1,3,3-tetraphenyl-1,3-bis(3-aminoethyl)disiloxane. propyl)disiloxane, 1,1,3,3-tetramethyl-1,3-bis(2-aminoethyl)disiloxane, 1,1,3,3-tetramethyl-1,3-bis(3-aminopropyl)disiloxane, 1,1,3,3-tetramethyl-1,3-bis(3-aminobutyl)disiloxane, and 1,3-dimethyl-1,3-dimethoxy-1,3-bis(4-aminobutyl)disiloxane. Examples of siloxane diamines represented by formula (5) where d is 2 include 1,1,3,3,5,5-hexamethyl-1,5-bis(4-aminophenyl)trisiloxane, 1,1,5,5-tetraphenyl-3,3-dimethyl-1,5-bis(3-aminopropyl)trisiloxane, 1,1,5,5-tetraphenyl-3,3-dimethoxy-1,5-bis(4-aminobutyl)trisiloxane, 1,1,5,5-tetraphenyl-3,3-dimethoxy-1,5-bis(5-aminopentyl)trisiloxane, and 1,1,5,5-tetramethyl-3,3-dimethoxy-1,5-bis( 1,1,5,5-tetramethyl-3,3-dimethoxy-1,5-bis(4-aminobutyl)trisiloxane, 1,1,5,5-tetramethyl-3,3-dimethoxy-1,5-bis(5-aminopentyl)trisiloxane, 1,1,3,3,5,5-hexamethyl-1,5-bis(3-aminopropyl)trisiloxane, 1,1,3,3,5,5-hexaethyl-1,5-bis(3-aminopropyl)trisiloxane, and 1,1,3,3,5,5-hexapropyl-1,5-bis(3-aminopropyl)trisiloxane.

[0038] Examples of commercially available siloxane diamines include "PAM-E" (amino group equivalent weight 130 g / mol), "KF-8010" (amino group equivalent weight 430 g / mol), "X-22-161A" (amino group equivalent weight 800 g / mol), "X-22-161B" (amino group equivalent weight 1500 g / mol), "KF-8012" (amino group equivalent weight 2200 g / mol), "KF-8008" (amino group equivalent weight 5700 g / mol), and "X-22-94 Examples of suitable siloxane diamines include "BY-16-09" (amino group equivalent 700 g / mol, side chain phenyl type), "X-22-1660B-3" (amino group equivalent 2200 g / mol, side chain phenyl type) (all manufactured by Shin-Etsu Chemical Co., Ltd.), "BY-16-853U" (amino group equivalent 460 g / mol), "BY-16-853" (amino group equivalent 650 g / mol), and "BY-16-853B" (amino group equivalent 2200 g / mol) (all manufactured by Dow Corning Toray Co., Ltd.). These can be used alone or in combination of two or more. Among these, siloxane diamines may be selected from "PAM-E", "KF-8010", "X-22-161A", "X-22-161B", "BY-16-853U", and "BY-16-853" in terms of reactivity with maleimide groups. In terms of dielectric properties, siloxane diamines may be selected from "PAM-E," "KF-8010," "X-22-161A," "BY-16-853U," and "BY-16-853." In terms of varnish compatibility, siloxane diamines may be selected from "KF-8010," "X-22-161A," and "BY-16-853."

[0039] The content of siloxane groups in the siloxane group-containing polyimide resin is not particularly limited, but may be 5 to 50 mass% based on the mass of the polyimide resin from the viewpoints of reactivity and compatibility, 5 to 30 mass% from the viewpoint of heat resistance, and 10 to 30 mass% from the viewpoint of further reducing moisture absorption.

[0040] The polyimide resin may be a polymer synthesized from a diamine other than siloxane diamine, or may be a polymer synthesized from a combination of siloxane diamine and other diamine.

[0041] Other diamines used as raw materials for polyimide resins are not particularly limited, and examples thereof include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethenemethane, bis(4-amino-3,5-dimethylphenyl)methane, bis(4- Amino-3,5-diisopropylphenyl)methane, 3,3'-diaminodiphenyldifluoromethane, 3,4'-diaminodiphenyldifluoromethane, 4,4'-diaminodiphenyldifluoromethane, 3,3'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenyl Ketone, 3,4'-diaminodiphenyl ketone, 4,4'-diaminodiphenyl ketone, 2,2-bis(3-aminophenyl)propane, 2,2'-(3,4'-diaminodiphenyl)propane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-(3,4'-diaminodiphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 1,3-bis(3-aminophenoxy)benzene, 1, 4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 3,3'-(1,4-phenylenebis(1-methylethylidene))bisaniline, 3,4'-(1,4-phenylenebis(1-methylethylidene))bisaniline, 4,4'-(1,4-phenylenebis(1-methylethylidene))bisaniline, 2,2-bis(4-(3-aminophenoxy)phenyl)propane, 2,2-bis(4-(3-aminophenoxy)phenyl)hexafluoropropane, 2,Examples of the diamine include aromatic diamines such as 2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, bis(4-(3-aminophenoxy)phenyl)sulfide, bis(4-(4-aminophenoxy)phenyl)sulfide, bis(4-(3-aminophenoxy)phenyl)sulfone, bis(4-(4-aminophenoxy)phenyl)sulfone, 3,3'-dihydroxy-4,4'-diaminobiphenyl, and 3,5-diaminobenzoic acid, 1,3-bis(aminomethyl)cyclohexane, 2,2-bis(4-aminophenoxyphenyl)propane, aliphatic ether diamines represented by the following general formula (4), aliphatic diamines represented by the following general formula (11), and diamines having a carboxyl group and / or a hydroxyl group. [ka] In formula (4), Q 1 , Q 2 and Q 3 each independently represents an alkylene group having 1 to 10 carbon atoms; and b represents an integer of 2 to 80. [ka] In the formula (11), c represents an integer of 5 to 20.

[0042] Examples of the aliphatic ether diamine represented by the general formula (4) include those represented by the following general formula: [ka] and aliphatic ether diamines represented by the following general formula (12). [ka] In the formula (12), e represents an integer of 0 to 80.

[0043] Examples of the aliphatic diamine represented by the general formula (11) include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, and 1,2-diaminocyclohexane.

[0044] The diamines exemplified above can be used alone or in combination of two or more.

[0045] Tetracarboxylic dianhydrides can be used as raw materials for polyimide resins. Examples of tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, Bis(3,4-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride, 3,4,3',4'-benzophenonetetracarboxylic dianhydride, 2,3,2',3'-benzophenonetetracarboxylic dianhydride, 3,3,3',4'-benzophenonetetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,4,5-naphthalenetetracarboxylic dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, phenanthrene-1,8,9,10-tetracarboxylic dianhydride, pyrazine -2,3,5,6-tetracarboxylic dianhydride, thiophene-2,3,5,6-tetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride, bis(3,4-dicarboxyphenyl)methylphenylsilane dianhydride, bis(3,4-dicarboxyphenyl)diphenylsilane dianhydride, 1,4-bis(3,4-Dicarboxyphenyldimethylsilyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldicyclohexane dianhydride, p-phenylene bis(trimellitate anhydride), ethylene tetracarboxylic dianhydride, 1,2,3,4-butane tetracarboxylic dianhydride, decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexachloro Dronaphthalene-1,2,5,6-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, bis(exo-bicyclo[2,2,1]heptane-2,3-dicarboxylic dianhydride, bicyclo-[2,2,2]-oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 2,2-bis( 3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenyl)phenyl]propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenyl)phenyl]hexafluoropropane dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 1,4-bis(2-hydroxyhexafluoroisopropyl)benzenebis(trimellitic anhydride), 1,3-bis(2-hydroxyhexafluoroisopropyl)benzenebis(trimellitic anhydride), 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, tetrahydrofuran-2,3,4,5-tetracarboxylic acid dianhydride, and tetracarboxylic acid dianhydrides represented by the following general formula (7): [ka] In the formula (7), a represents an integer of 2 to 20.

[0046] Examples of tetracarboxylic dianhydrides represented by the general formula (7) above include those that can be synthesized from trimellitic anhydride monochloride and the corresponding diol, and specifically include 1,2-(ethylene)bis(trimellitate anhydride), 1,3-(trimethylene)bis(trimellitate anhydride), 1,4-(tetramethylene)bis(trimellitate anhydride), 1,5-(pentamethylene)bis(trimellitate anhydride), and 1,6-(hexamethylene)bis(trimellitate anhydride). , 1,7-(heptamethylene)bis(trimellitate anhydride), 1,8-(octamethylene)bis(trimellitate anhydride), 1,9-(nonamethylene)bis(trimellitate anhydride), 1,10-(decamethylene)bis(trimellitate anhydride), 1,12-(dodecamethylene)bis(trimellitate anhydride), 1,16-(hexadecamethylene)bis(trimellitate anhydride), and 1,18-(octadecamethylene)bis(trimellitate anhydride).

[0047] The tetracarboxylic dianhydride may include a tetracarboxylic dianhydride represented by the following general formula (6) or (8) from the viewpoint of imparting good solubility in a solvent and moisture resistance reliability. [ka] [ka]

[0048] The above-mentioned tetracarboxylic dianhydrides can be used alone or in combination of two or more.

[0049] Bismaleimide can be used as a raw material for polyimide resin. Although the bismaleimide is not particularly limited, examples thereof include bis(4-maleimidophenyl)methane, polyphenylmethane maleimide, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, m-phenylene bismaleimide, and 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane. These can be used alone or in combination of two or more. The bismaleimide may be selected from bis(4-maleimidophenyl)methane, bis(4-maleimidophenyl)sulfone, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethane bismaleimide, and 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane, which are highly reactive and can improve dielectric properties and wireability; from 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethane bismaleimide, bis(4-maleimidophenyl)methane, and 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane in terms of solubility in solvents; from bis(4-maleimidophenyl)methane in terms of inexpensiveness; and from the viewpoint of wireability, from 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane and BMI-3000 (product name) by Desiigner Molecules, Inc.

[0050] The thermosetting resin composition 12 includes a thermosetting resin, which is a compound that forms a crosslinked polymer upon heating. The thermosetting resin typically has a reactive functional group that undergoes a crosslinking reaction. The reactive functional group may be, for example, an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acryloyl group, a methacryloyl group, a vinyl group, a maleic anhydride group, or a combination thereof.

[0051] The content of the thermosetting resin may be, for example, 20 to 80 mass % based on the total mass of the components of the thermosetting resin composition 12 other than the inorganic filler.

[0052] The thermosetting resin composition 12 may contain an epoxy resin as a thermosetting resin. The epoxy resin may be a compound containing two or more epoxy groups. The epoxy resin may be a phenol glycidyl ether type epoxy resin in terms of curability and cured product properties. Examples of phenol glycidyl ether type epoxy resins include biphenylaralkyl type epoxy resins, bisphenol A type (or AD type, S type, or F type) glycidyl ethers, hydrated bisphenol A type glycidyl ethers, ethylene oxide adduct bisphenol A type glycidyl ethers, propylene oxide adduct bisphenol A type glycidyl ethers, phenol novolac resin glycidyl ethers, cresol novolac resin glycidyl ethers, bisphenol A novolac resin glycidyl ethers, naphthalene resin glycidyl ethers, trifunctional (or tetrafunctional) glycidyl ethers, and dicyclopentadiene phenol resin glycidyl ethers. Other examples of epoxy resins include glycidyl esters of dimer acids, trifunctional (or tetrafunctional) glycidyl amines, and glycidyl amines of naphthalene resins, which may be used alone or in combination of two or more.

[0053] The thermosetting resin composition 12 may contain an acrylate compound as a thermosetting resin. The acrylate compound may have two or more (meth)acryloyl groups. Examples of the acrylate compound include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, pentaerythritol triacrylate, and pentaerythritol triacrylate. Examples of the acrylate include methyl acrylate, methyl methacrylate, ... [ka]

[0054] In formula (13), R 41 and R 42each independently represents a hydrogen atom or a methyl group, and f and g each independently represent an integer of 1 or greater. A radiation-polymerizable compound having a glycol skeleton as represented by formula (13) can impart solvent resistance after curing. Urethane acrylate, urethane methacrylate, isocyanuric acid-modified di / triacrylate, and methacrylate can impart high adhesiveness after curing.

[0055] The thermosetting resin composition 12 may contain a thermosetting elastomer selected from styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic elastomers, and silicone-based elastomers. Thermosetting elastomers are composed of hard segment components and soft segment components, with the hard segment components generally contributing to heat resistance and strength, and the soft segment components contributing to flexibility and toughness. These thermosetting elastomers may be used alone or in combination of two or more. The thermosetting elastomer may be selected from styrene-based elastomers, olefin-based elastomers, polyamide-based elastomers, and silicone-based elastomers in terms of heat resistance and insulation reliability, or from styrene-based elastomers and olefin-based elastomers in terms of dielectric properties.

[0056] The thermosetting elastomer has a reactive functional group at the molecular end or in the molecular chain. Examples of the reactive functional group include an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acryloyl group, a methacryloyl group, a vinyl group, and a maleic anhydride group. From the viewpoints of compatibility and wireability, the reactive functional group of the thermosetting elastomer may be an epoxy group, an amino group, an acryloyl group, a methacryloyl group, a vinyl group, or a maleic anhydride group, or may be an epoxy group, an amino group, or a maleic anhydride group. The content of the thermosetting elastomer may be 10 to 70 mass% based on the mass of the thermosetting resin composition, or may be 20 to 60 mass% from the viewpoints of dielectric properties and varnish compatibility.

[0057] The thermosetting resin composition may optionally contain a curing accelerator that accelerates the curing reaction of the thermosetting resin. Examples of the curing accelerator include peroxides, imidazole compounds, organic phosphorus compounds, secondary amines, tertiary amines, and quaternary ammonium salts. These may be used alone or in combination of two or more. When the thermosetting resin is an epoxy resin, the curing accelerator may be, for example, an imidazole compound.

[0058] The content of the curing accelerator may be 0.1 to 10 mass% based on the total mass of the components other than the inorganic filler in the thermosetting resin composition, or may be 0.5 to 5 mass%, or 0.75 to 3 mass% from the viewpoints of dielectric properties and handling properties of the prepreg.

[0059] The thermosetting resin composition 12 may contain an adhesion aid, such as a silane coupling agent, a triazole compound, or a tetrazole compound.

[0060] The silane coupling agent may be a compound having a nitrogen atom to improve adhesion to metal. Examples of the silane coupling agent include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, and 3-isocyanatepropyltriethoxysilane.

[0061] The content of the silane coupling agent may be 0.1 to 20 mass % based on the total mass of components other than the inorganic filler in the thermosetting resin composition 12, from the viewpoints of the effect of addition, heat resistance, production costs, and the like.

[0062] Examples of the triazole compound include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenone], and 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenone]. ol], 6-(2-benzotriazolyl)-4-tert-octyl-6'-tert-butyl-4'-methyl-2,2'-methylenebisphenol, 1,2,3-benzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole, carboxybenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole, and 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol.

[0063] Examples of tetrazole compounds include 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 1-methyl-5-ethyl-1H-tetrazole, 1-methyl-5-mercapto-1H-tetrazole, 1-phenyl-5-mercapto-1H-tetrazole, 1-(2-dimethylaminoethyl)-5-mercapto-1H-tetrazole, 2-methoxy-5-(5-trifluoromethyl-1H-tetrazol-1-yl)-benzaldehyde, 4,5-di(5-tetrazolyl)-[1,2,3]triazole, and 1-methyl-5-benzoyl-1H-tetrazole.

[0064] The content of the triazole compound and the tetrazole compound may be 0.1 to 20 mass % based on the total mass of the components other than the inorganic filler in the thermosetting resin composition 12, from the viewpoints of the effect of addition, heat resistance, and production costs.

[0065] The silane coupling agent, the triazole compound, and the tetrazole compound may be used alone or in combination.

[0066] The thermosetting resin composition 12 may contain an ion scavenger. The ion scavenger adsorbs ionic impurities in the organic insulating layer, thereby improving insulation reliability during moisture absorption. Examples of ion scavenger include compounds known as copper inhibitors for preventing copper from ionizing and dissolving, such as triazine thiol compounds and phenol-based reducing agents, as well as inorganic compounds based on bismuth, antimony, magnesium, aluminum, zirconium, calcium, titanium, tin, or mixtures thereof.

[0067] Examples of commercially available ion scavengers include inorganic ion scavengers manufactured by Toagosei Co., Ltd. (trade names: IXE-300 (antimony-based), IXE-500 (bismuth-based), IXE-600 (antimony and bismuth mixed), IXE-700 (magnesium and aluminum mixed), IXE-800 (zirconium-based), and IXE-1100 (calcium-based)). These may be used alone or in combination of two or more.

[0068] The content of the ion scavenger may be 0.01 to 10 mass % based on the total mass of the components of the thermosetting resin composition 12 other than the inorganic filler, from the viewpoints of the effect of addition, heat resistance, production costs, and the like.

[0069] The thermosetting resin composition 12 may contain a filler to impart low moisture absorption and low moisture permeability. The filler may be an inorganic filler, an organic filler, or a combination thereof. The inorganic filler can be added to the insulating substrate for the purpose of imparting thermal conductivity, low thermal expansion, low moisture absorption, etc., to the insulating substrate. The organic filler can be added to the insulating substrate for the purpose of imparting toughness, etc., to the insulating substrate.

[0070] Examples of inorganic fillers include alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, crystalline silica, amorphous silica, boron nitride, titania, glass, iron oxide, ceramic, and carbon. Examples of organic fillers include rubber-based fillers. These inorganic or organic fillers can be used alone or in combination of two or more. The thermosetting resin composition 12 may contain a silica filler and / or an alumina filler.

[0071] The average particle size of the filler may be 10 μm or less or 5 μm or less. The maximum particle size of the filler may be 30 μm or less or 20 μm or less. If the average particle size exceeds 10 μm and the maximum particle size exceeds 30 μm, it tends to be difficult to obtain the effect of improving fracture toughness. There are no particular restrictions on the lower limits of the average particle size and the maximum particle size, but they are usually 0.001 μm.

[0072] The filler may have both an average particle size of 10 μm or less and a maximum particle size of 30 μm or less. Fillers with a maximum particle size of 30 μm or less but an average particle size of more than 10 μm tend to relatively reduce adhesive strength. Fillers with an average particle size of 10 μm or less but a maximum particle size of more than 30 μm tend to increase variability in adhesive strength.

[0073] The average particle size and maximum particle size of the filler can be measured, for example, by using a scanning electron microscope (SEM) to measure the particle size of fillers on the order of 1000 particles. In the case of a measurement method using an SEM, for example, a cured product obtained by heat-curing a thermosetting resin composition may be produced, and the cross section of the central part of the cured product may be observed with the SEM. The probability of the presence of fillers with particle sizes of 30 μm or less may be 80% or more of all fillers.

[0074] The content of the filler (particularly the inorganic filler) may be, for example, 40 to 300 mass % based on the total mass of the components of the thermosetting resin composition 12 other than the filler.

[0075] The thermosetting resin composition may contain an antioxidant to improve storage stability, prevent electromigration, and prevent corrosion of the metal conductor circuit. Examples of antioxidants include benzophenone-based, benzoate-based, hindered amine-based, benzotriazole-based, and phenol-based antioxidants. The content of the antioxidant may be 0.01 to 10% by mass based on the total mass of the components of the thermosetting resin composition 12 other than the inorganic filler, in terms of the effect of addition, heat resistance, cost, etc.

[0076] The dielectric constant of the cured product of the thermosetting resin composition 12 at 10 GHz may be 3.0 or less, and may be 2.8 or less to further improve the reliability of electrical signals. The dielectric loss tangent of the cured product of the thermosetting resin composition 12 at 10 GHz may be 0.005 or less. The dielectric constant can be measured using a test piece of the cured product of the thermosetting resin composition, which is 60 mm long, 2 mm wide, and 300 μm thick. The test piece may be vacuum dried at 30°C for 6 hours before measurement. The dielectric loss tangent can be calculated from the resonant frequency and unloaded Q value obtained at 10 GHz. The measurement device may be a Keysight Technologies vector network analyzer E8364B, a Kanto Electronics Application Development CP531 (10 GHz resonator), and a CPMAV2 (program). The measurement temperature may be 25°C.

[0077] The glass transition temperature of the cured product formed by thermal curing of the thermosetting resin composition 12 may be 120°C or higher in order to suppress cracking during temperature cycling, or 140°C or higher in order to alleviate stress on wiring. The glass transition temperature of the cured product may be 240°C or lower in order to enable lamination at low temperatures, or 220°C or lower in order to suppress cure shrinkage.

[0078] The width of the prepreg 1 may be, for example, 200 to 1,300 mm. The thickness of the prepreg 1 may be, for example, 15 to 300 μm. If the thickness of the prepreg 1 is less than 15 μm, unevenness resulting from the inorganic fiber base material 11 tends to remain, resulting in a relatively reduced flatness. If the thickness of the prepreg 1 is more than 300 μm, warpage tends to increase.

[0079] The prepreg 1 can be obtained, for example, by a method including impregnating an inorganic fiber substrate 11 with a resin varnish containing a thermosetting resin composition 12 and a solvent, and removing the solvent from the resin varnish.

[0080] 2 and 3 are cross-sectional views showing an example of a method for producing a substrate material for a semiconductor package. The method shown in Figures 2 and 3 includes, in this order, a step of raising the temperature of a laminate 5 having a metal foil 3, two or more prepregs 1, and the metal foil 3 stacked in this order, to a heat-press temperature while applying pressure to the laminate 5, and a step of heating the laminate 5 at a temperature equal to or higher than the heat-press temperature while applying pressure to the laminate 5 in its thickness direction, thereby forming a substrate material 100 for a semiconductor package having an insulating substrate 10 formed by integrating the two or more prepregs 1, and metal foils 3 provided on both sides of the insulating substrate 10.

[0081] In the process of increasing the temperature of the laminate 5 to a heat-press temperature while applying pressure to the laminate 5, the laminate 5 is heated under heating conditions that result in the minimum melt viscosity of the prepreg 1 being 5000 Pa·s or less or 4000 Pa·s or less. This heat-pressing method, which includes a temperature-raising process, allows for easy production of a semiconductor package substrate material 100 with minimal thickness variation. Using the semiconductor package substrate material 100, semiconductor devices that transmit high-frequency signals and have fine wiring and chips with fine bumps connected thereto can be manufactured with high reliability and productivity. The resulting semiconductor package substrate material 100 also exhibits excellent warpage reduction. The heating conditions here refer to conditions related to the temperature profile and may include the temperature-raising rate, as well as the holding temperature and holding time when the laminate 5 is held at a predetermined holding temperature. The temperature-raising rate may be constant or variable.

[0082] In the step of raising the temperature of the laminate 5 to a heat press temperature while applying pressure to the laminate 5, the laminate 5 may be heated under conditions such that the minimum melt viscosity of the prepreg 1 is 1000 Pa·s or more and 5000 Pa·s or less, or 1000 Pa·s or more and 4000 Pa·s or less. If the minimum melt viscosity of the prepreg 1 during the temperature rise is 1000 Pa·s or more, the variation in thickness of the semiconductor package substrate material 100 tends to be further reduced.

[0083] In the step of increasing the temperature of the laminate 5 to the heat-pressing temperature while applying pressure to the laminate 5, the melt viscosity of the prepreg 1 decreases to the minimum melt viscosity and then increases as the curing reaction progresses. FIG. 4 is a graph showing an example of the results of measuring the melt viscosity of a prepreg. FIG. 4 is a graph showing the relationship between the melt viscosity (complex viscosity) of a prepreg and temperature, and shows melt viscosities measured for the same prepreg at heating rates of 3°C / min, 4°C / min, or 6°C / min. As illustrated in FIG. 4, generally, a higher heating rate tends to decrease the minimum melt viscosity of the prepreg 1. The heating rate in the step of increasing the temperature of the laminate 5 to the heat-pressing temperature while applying pressure to the laminate 5 may be, for example, 2°C / min or more, 3°C / min or more, or 4°C / min or more, or may be 8°C / min or less, 7°C / min or less, or 6°C / min or less.

[0084] In the step of raising the temperature of the laminate 5 to a heat-press temperature while applying pressure to the laminate 5, when the melt viscosity of the prepreg decreases to 10,000 Pa·s at temperature T1 [°C] as the temperature of the laminate increases, and then rises to 10,000 Pa·s at temperature T2 [°C] after passing through the minimum melt viscosity, the difference between T1 and T2 may be 20°C or more. T1 and T2 in FIG. 4 are T1 and T2 when the heating rate is 4°C / min. From the viewpoint of further suppressing variation in wiring width, the difference between T1 and T2 may be 20°C or more, or 25°C or more, or may be 50°C or less.

[0085] In the step of increasing the temperature of the laminate 5 to the heat press temperature while pressing the laminate 5, the temperature of the laminate 5 starts from a temperature in the range of, for example, 20 to 120°C and is increased to the heat press temperature.

[0086] In the step of increasing the temperature of the laminate 5 to the heat press temperature while applying pressure to the laminate 5, the temperature at which the prepreg 1 exhibits the minimum melt viscosity may be 80°C or higher or 120°C or higher, or may be 200°C or lower or 180°C or lower.

[0087] The step of raising the temperature of the laminate 5 to the heat-press temperature while pressing the laminate 5 may include, in this order, raising the temperature of the laminate 5 to a holding temperature that is lower than the heat-press temperature and within a range of ±20°C of the temperature at which the prepreg 1 exhibits the minimum melt viscosity, holding the laminate 5 at the holding temperature for 5 to 90 minutes, and raising the temperature of the laminate 5 from the holding temperature to the heat-press temperature. During these steps, the laminate 5 is usually continuously pressed.

[0088] The laminate 5, whose temperature has been raised to the heat press temperature, is further heated and pressurized at a temperature equal to or higher than the heat press temperature, thereby forming a substrate material 100 for a semiconductor package. During the heating and pressurization at a temperature equal to or higher than the heat press temperature, a curing reaction of the thermosetting resin composition in the prepreg 1 proceeds, resulting in the formation of an insulating substrate 10 including an insulating resin layer 12A, which is a cured product of the thermosetting resin composition, and an inorganic fiber substrate 11 disposed within the insulating resin layer 12A. The heat press temperature may be, for example, 100 to 250°C or 150 to 300°C. The heating and pressurization time after the temperature increase may be, for example, 0.1 to 5 hours. The substrate material 100 after heating and pressurization may be further heated as necessary. The content of the insulating resin layer 12A in the insulating substrate 10 is substantially the same as the content of the thermosetting resin composition 12 in the prepreg 1, and may be, for example, 40 to 80 mass% based on the mass of the insulating substrate 10.

[0089] The laminate 5 is usually continuously pressed from the temperature rise to the heating and pressing at the heat press temperature. The pressure applied to the laminate 5 from the temperature rise to the heating and pressing at the heat press temperature may be, for example, 0.2 to 10 MPa.

[0090] From the viewpoint of electrical conductivity, the metal foil 3 may contain copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing at least one of these metal elements. The metal foil 3 may be a copper foil, an aluminum foil, or a copper foil.

[0091] The device for heating and pressurizing the laminate 5 may be, for example, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, or an autoclave molding machine.

[0092] When the inorganic fiber substrate 11 constituting the prepreg 1 is a woven fabric containing inorganic fibers, two or more prepregs may be laminated with the inorganic fibers oriented in the same direction, or with the inorganic fibers oriented at right angles to each other.

[0093] In the heat press for forming the substrate material for a semiconductor package, a metal plate may be placed on the surface of the metal foil 3 opposite to the prepreg 1. The thickness of the metal plate may be 0.5 mm to 7 mm. If the metal plate is thinner than 0.5 mm, the metal plate may be easily moved. If the metal plate is thicker than 7 mm, handling may be impaired. The metal plate may be, for example, a stainless steel plate.

[0094] The standard deviation of the thickness measured at any number of points in an area of ​​any size within the metal plate may be 4 μm or less. The standard deviation of the thickness of the metal plate may be, for example, T1, T2, . . . , T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20, T n and the average thickness of the metal plate is T, it can be calculated using the following formula.

number

[0095] In the hot press for forming the substrate material for a semiconductor package, a cushioning material may be placed on the surface of the metal foil 3 opposite to the prepreg 1. The cushioning material may be, for example, a paper material with a thickness of about 0.2 mm. Both the cushioning material and the metal plate may be used.

[0096] The heat pressing to form the substrate material for semiconductor packages may be performed in multiple steps. For example, a method for producing a substrate material for semiconductor packages may further include the steps of laminating one or more additional prepregs on the insulating substrate formed by the first heat pressing to form a second laminate, and forming an insulating substrate after the second lamination, including a portion formed from the additional prepregs, by heat pressing, including increasing the temperature of the second laminate while applying pressure to the second laminate. In this case, the additional prepreg may also contain an inorganic fiber base material and a thermosetting resin composition impregnated into the inorganic fiber base material. The content of the thermosetting resin composition may be 40% by mass or more and 80% by mass or less based on the mass of the additional prepreg. The additional prepreg may be the same as or different from the prepreg constituting the laminate in the first heat pressing. In the heat pressing to form the insulating substrate after the second lamination, the temperature of the second laminate is increased under heating conditions such that the minimum melt viscosity of the additional prepreg is 5000 Pa·s or less. Typically, the metal foil is removed from the first laminate before additional prepregs are laminated to the insulating substrate.

[0097] When two or more prepregs 1 are used, they may include two or more types of prepregs with different minimum melt viscosities. In this case, the laminate 5 is heated under conditions such that the maximum of the minimum melt viscosities of the two or more types of prepregs is 5000 Pa·s or less. For example, from the perspective of reducing variation in thickness of substrate materials for semiconductor packages, the laminate to be heated and pressurized may include one or more prepregs with a minimum melt viscosity of 5000 Pa·s or less and, on both sides of the prepreg, one or more prepregs with a minimum melt viscosity of 3000 Pa or less.

[0098] From the viewpoint of productivity, the width of the substrate material 100 for a semiconductor package may be 200 to 1,300 mm, and the thickness of the substrate material 100 for a semiconductor package may be 200 to 1,500 μm.

[0099] The substrate material 100 for a semiconductor package can have a thickness with small variations. For example, the standard deviation of the thickness of the substrate material for a semiconductor package may be 4 μm or less, 3.5 μm or less, 3 μm or less, 2.5 μm or less, or 2 μm or less, or may be 0.1 μm or more. The standard deviation of the thickness of the substrate material 100 for a semiconductor package is calculated by multiplying the thicknesses T1, T2, . . . , T3 of the substrate material 100 for a semiconductor package at each of any n positions. n The value σ may be calculated from the following formula:

number

[0100] The standard deviation of the thickness of the substrate material 100 for a semiconductor package may be a value determined by a method including dividing the entire main surface of the substrate material for a semiconductor package into a plurality of square areas with sides of 50 mm, measuring the thickness at four locations 2 mm inward from the four corners of each area, calculating the value of the standard deviation of the thickness using the thickness values ​​measured at the four locations in each area as a population, and setting the maximum value of the standard deviation of the thickness calculated in each area as the standard deviation of the thickness of the substrate material 100 for a semiconductor package.

[0101] The position at which the thickness of the semiconductor package substrate material 100 is measured is, for example, 2500 mm across the entire main surface of the semiconductor package substrate material 100. 2 The area is divided into multiple regions with an area of ​​2500mm, and one or more items can be selected from each region. 2 The entire main surface of the semiconductor package substrate material 100 is divided so as to maximize the number of regions having an area of ​​100. The thickness is measured using, for example, a micrometer.

[0102] The substrate material 100 for semiconductor packages can be used, for example, as a core material for forming a wiring substrate for semiconductor packages on which a semiconductor chip is mounted. By utilizing the metal foil 3 of the substrate material 100 for semiconductor packages or by removing the metal foil 3 and forming wiring on the exposed insulating substrate, a wiring substrate for semiconductor packages having fine wiring can be manufactured.

[0103] The wiring board for semiconductor packages can be obtained, for example, by a method including forming wiring on metal foil 3 by a subtractive method, or by a method including forming wiring by a semi-additive method after removing metal foil 3 as needed. If necessary, through holes penetrating insulating substrate 10 may be formed, and conductive vias may be formed to fill the through holes.

[0104] A semiconductor package is manufactured by mounting a semiconductor chip, memory, etc., at a predetermined position on a wiring substrate for a semiconductor package. The wiring substrate for a semiconductor package obtained using the substrate material for a semiconductor package according to this embodiment has small variations in thickness, which tends to improve the yield of the process of mounting the semiconductor chip. Furthermore, a semiconductor chip having minute solder bumps can be more easily mounted on the wiring substrate.

[0105] A build-up layer may be formed on the wiring substrate for a semiconductor package. In this case, wiring connected to the semiconductor chip may be formed on the build-up layer. The build-up layer may be formed by, for example, a subtractive method, a full-additive method, a semi-additive method (SAP: Semi-Additive Process), a modified semi-additive method (m-SAP: Modified Semi-Additive Process), or a trench method.

[0106] The trench method involves forming a build-up material or photosensitive insulating material layer having a pattern including grooves on a wiring substrate and filling the grooves with a conductive material. The conductive material formed outside the grooves is removed by methods such as CMP or fly-cutting. If the thickness of the substrate material for semiconductor packages is small, the conductive material formed outside the grooves can be easily removed while leaving the conductive material filled in the grooves. [Example]

[0107] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to the following examples.

[0108] 1.Prepreg Preparation Prepreg A 24 g of zircone diamine (trade name "KF-8010", manufactured by Shin-Etsu Silicones), 240 g of bis(4-maleimidophenyl)methane, and 400 g of propylene glycol monomethyl ether were placed in a flask equipped with a stirrer, a thermometer, and a nitrogen purge device. The reaction solution was heated at 115°C for 4 hours to produce polyimide resin 1. The reaction solution was then heated to 130°C under atmospheric pressure and concentrated to obtain a polyimide resin solution with a concentration of 60% by mass.

[0109] The resulting polyimide resin solution (polyimide resin content: 50 g) was mixed with an epoxy resin solution prepared by dissolving 40 g of biphenylaralkyl epoxy resin (product name "NC-3000-H" manufactured by Nippon Kayaku Co., Ltd.) in propylene glycol monomethyl ether, 0.5 g of a curing accelerator (product name "2P4MHZ-PW" manufactured by Shikoku Kasei Co., Ltd.), a silica slurry containing 40 g of silica filler (product name "SC2050-KNK" manufactured by Admatechs Co., Ltd.), and N-methylpyrrolidone. The mixture was stirred for 30 minutes to obtain a resin varnish. The total concentration of the polyimide resin and epoxy resin in the resin varnish was 65% by mass. The resulting resin varnish was impregnated into a glass cloth (thickness: 0.1 mm) made of E-glass fiber and dried by heating at 150°C for 10 minutes to obtain prepreg A with a resin content (content of the thermosetting resin composition) of 50% by mass.

[0110] Prepreg B Prepreg B was produced in the same manner as prepreg A, except that the resin content was changed to 70 mass %.

[0111] Prepreg C A flask equipped with a stirrer, thermometer, and nitrogen purge device was charged with 10.3 g of 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 4.1 g of 1,4-butanediol bis(3-aminopropyl)ether (trade name "B-12" manufactured by Tokyo Chemical Industry Co., Ltd.), and 101 g of N-methylpyrrolidone. Next, 20.5 g of 1,2-(ethylene)bis(trimellitate anhydride) was added. The reaction solution was stirred at room temperature for 1 hour, and then a reflux condenser with a water receiver was attached to the flask. The reaction solution was heated to 180°C while blowing in nitrogen gas, and the temperature was maintained for 5 hours while removing water to allow the reaction to proceed, producing polyimide resin 2. The polyimide resin solution was then cooled to room temperature.

[0112] The resulting polyimide resin solution (polyimide resin content: 50 g) was mixed with an epoxy resin solution prepared by dissolving 40 g of biphenylaralkyl epoxy resin (product name "NC-3000-H" manufactured by Nippon Kayaku Co., Ltd.) in N-methylpyrrolidone, 0.5 g of a curing accelerator (imidazole compound, product name "2P4MHZ-PW" manufactured by Shikoku Kasei Co., Ltd.), 40 g of silica filler-containing silica slurry (product name "SC2050-KNK" manufactured by Admatechs Co., Ltd.), and N-methylpyrrolidone. The mixture was stirred for 30 minutes to obtain a resin varnish. The total concentration of polyimide resin and epoxy resin in the resin varnish was 65% by mass. The resulting resin varnish was impregnated into a glass cloth (thickness: 0.1 mm) made of E-glass fiber and dried by heating at 150°C for 10 minutes to obtain prepreg C with a resin content of 50% by mass.

[0113] Prepreg D Prepreg D was produced in the same manner as prepreg C, except that the resin content was changed to 70 mass %.

[0114] Prepreg E Prepreg E was produced in the same manner as prepreg A, except that the resin content was changed to 35% by mass.

[0115] Prepreg F A polyimide solution containing polyimide resin 1 (polyimide content: 50 g), an epoxy resin solution prepared by dissolving 60 g of biphenylaralkyl epoxy resin (product name "NC-3000-H" manufactured by Nippon Kayaku Co., Ltd.) in propylene glycol monomethyl ether, 1.5 g of a curing accelerator (imidazole compound, product name "2P4MZ" manufactured by Shikoku Kasei Co., Ltd.), a silica slurry containing 50 g of silica filler (product name "SC2050-KNK" manufactured by Admatechs Co., Ltd.), and N-methylpyrrolidone were mixed together and stirred for 30 minutes to obtain a resin varnish. The total concentration of polyimide resin and epoxy resin in the resin varnish was 65% by mass. The resulting resin varnish was impregnated into a glass cloth (thickness: 0.1 mm) made of E-glass fiber, and the resulting resin varnish was dried by heating at 150°C for 10 minutes to obtain prepreg F with a resin content of 50% by mass.

[0116] Prepreg G Prepreg G was produced in the same manner as prepreg A, except that the resin content was changed to 40 mass %.

[0117] Prepreg H Prepreg H was produced in the same manner as prepreg A, except that the resin content was changed to 80 mass %.

[0118] 2. Melt viscosity of prepreg The prepared prepreg was sandwiched between two parallel plates with a diameter of 8 mm, and the melt viscosity (complex viscosity) of the laminate was measured in shear mode at a frequency of 10 Hz using a viscoelasticity measuring device (ARES, manufactured by Rheometrics Scientific F.E., Inc.) under the heating condition A below. From the measurement results, the minimum melt viscosity was calculated. The temperature T1 [°C] at which the melt viscosity decreased to 10,000 Pa·s with increasing temperature, and the temperature T2 [°C] at which the melt viscosity subsequently increased to 10,000 Pa·s after passing the minimum melt viscosity, were calculated, and the difference between T1 and T2 (T2 - T2) was calculated. Furthermore, the melt viscosity was measured by 1000 x 10 3 The rate of increase in melt viscosity per minute was determined while the viscosity rose to Pa·s. For prepreg A, the melt viscosity was measured when the temperature rise conditions were changed to the following conditions B or C. The measurement results are shown in Table 1. Condition A: Heating rate: 4°C / min from 20°C to 250°C Condition B: Heating rate 6°C / min from 20°C to 250°C Condition C: The temperature was raised from room temperature (approximately 25°C) to 140°C at a rate of 6°C / min, and the temperature was held at 140°C for 30 minutes under pressure. The temperature was then raised from 140°C to 230°C at a rate of 6°C / min. The temperatures at which prepreg A showed the minimum melt viscosity were 135°C under condition A and 145°C under condition B.

[0119] [Table 1]

[0120] 3. Preparation of Substrate Materials One of prepregs A to H was cut into a square with sides of 250 mm. Four cut prepregs were stacked, and copper foil (MT18EX-5, manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed on both sides of the stack. The prepreg and copper foil laminate was pressed at a pressure of 3 MPa and a vacuum of 40 hPa using a press machine (MHPC-VF-350-350-3-70, manufactured by Meiki Seisakusho Co., Ltd.) with five 0.2 mm-thick cushioning materials (KS190, manufactured by Oji Paper Co., Ltd.) sandwiched between the laminate and the prepreg. While applying pressure, the temperature of the press machine was increased under the following conditions A, B, or C, and the laminate was then heated and pressed at 230°C for 2 hours. Subsequently, 25 mm-wide edges along the four sides of the laminate were cut off using a cutter to obtain a substrate material with a square main surface with sides of 200 mm. Table 2 shows the combinations of prepregs and heating conditions used in each example or comparative example. Condition A: Heat from room temperature (approximately 25°C) to 230°C at a rate of 4°C / min Condition B: Heat from room temperature (approximately 25°C) to 230°C at a rate of 6°C / min Condition C: The temperature was raised from room temperature (approximately 25°C) to 140°C at a rate of 6°C / min, and the temperature was held at 140°C for 30 minutes under pressure. The temperature was then raised from 140°C to 230°C at a rate of 6°C / min.

[0121] 4. Evaluation of substrate materials The flatness (thickness variation) of the substrate material, solder bump connectivity, fine wiring formability, and wiring width variation were evaluated by the following methods. The evaluation results are shown in Table 2. The minimum melt viscosity of the prepreg shown in Table 2 is the minimum melt viscosity measured under heating conditions equivalent to those employed in each example or comparative example.

[0122] Flatness (thickness variation) The main surface of the substrate material was divided into 16 square areas with sides of 50 mm, and the thickness of each area was measured 2 mm inward from the four corners using a micrometer (Mitutoyo, ID-C112X). The difference between the maximum and minimum thickness values ​​measured at four points in each of the 16 areas was calculated, and the average value of the differences between the maximum and minimum thickness values ​​for the 16 areas (average thickness difference) was calculated. The thickness values ​​measured at the four points in each of the 16 areas were used as the population to calculate the standard deviation of the thickness. The maximum of the standard deviations of the thickness for each of the 16 areas was recorded as the standard deviation of the substrate material.

[0123] warp The substrate material was placed on a horizontal table, and the distances between the four sides of the 200 mm square substrate material and the surface of the table were measured. The maximum of the four measured distances was recorded as the value of the warpage of the substrate material.

[0124] Solder Bump Connectivity Test substrate materials with square main surfaces measuring 50 mm on a side were cut from the substrate material by dicing. The substrate material was immersed in a 10% by weight sulfuric acid solution for 1 minute. After rinsing with water, a fluxing agent (SPARKLEFLUX WF-6317, manufactured by Senju Metal Industry Co., Ltd.) was applied to the surface of the substrate material. A semiconductor chip with solder bumps was placed on the fluxing surface of the substrate material and heated in a reflow machine (SNR-1065GT, manufactured by Senju Metal Industry Co., Ltd.) set to a maximum temperature of 260°C under a nitrogen atmosphere to mount the semiconductor chip to the substrate material. The semiconductor chip used here had copper pillars with a diameter of 75 μm and a height of 45 μm, and 15 μm-high solder bumps (SnAg) provided on them, with connection terminals arranged at a 150 μm pitch. The semiconductor chip had a square main surface with a side length of 25 mm, obtained by dicing a silicon wafer (manufactured by Waltz, FBW150-00SnAg01JY) with a thickness of 725 μm.

[0125] The substrate material and the chip mounted thereon were cleaned using an ultrasonic cleaner at a frequency of 45 kHz for 10 minutes to remove the fluxing agent, followed by drying at 100°C for 30 minutes. Next, underfill was injected between the substrate material and the semiconductor chip on a hot plate heated to 110°C, and the package was further heated at 150°C for 2 hours to obtain a semiconductor package for evaluation. Ten cross sections of each solder bump located at the four corners of the semiconductor chip in the resulting semiconductor package were observed using a scanning electron microscope to confirm the connection between the solder bump and the copper foil of the substrate material. A total of 120 locations were observed for three semiconductor packages fabricated using the same procedure. The percentage of locations where connection between the solder bump and the copper foil of the substrate material was confirmed was calculated. A percentage of 90% or more was rated "A," and a percentage of less than 90% was rated "B."

[0126] Fine wiring formability Test substrate materials with square main surfaces measuring 50 mm on a side were cut from the substrate material by dicing. The copper foil was removed from the substrate material by etching in an ammonium persulfate solution. A photosensitive insulating material (Hitachi Chemical, AR5100) was applied to the exposed insulating substrate using a slit coater. The coating was dried by heating at 120°C for 1 minute and then cured by heating at 230°C for 2 hours in a nitrogen atmosphere to form a 5 μm-thick insulating resin layer. A seed layer consisting of a titanium layer (50 nm thick) and a copper layer (150 nm thick) was formed on the insulating resin layer by sputtering. A photoresist layer (Hitachi Chemical, RY-5107UT) was then formed on the seed layer, and a 70 mm square area of ​​the photoresist was exposed to UV light using a projection exposure system (Therma Precision, S6Ck exposure system). The exposed photoresist was developed by spraying a 1% by mass aqueous solution of sodium carbonate using a spin developer (Blue Ocean Technology, Inc., ultra-high-pressure spin developer). This exposure and development process resulted in the formation of 20 patterns, each consisting of 20 400 μm-long straight lines arranged with a resist width / space width of 2 μm / 2 μm. The exposed seed layer surface was treated with oxygen plasma for 1 minute using a plasma asher (Nordson Advanced Technology, AP Series batch plasma processing system) at 500 W power, 150 mTorr pressure, and 100 sccm gas flow. A 3 μm-thick copper plating was then formed on the seed layer by electrolytic copper plating. The photoresist was stripped using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. The exposed seed layer was then washed for 30 seconds at 23°C using an aqueous solution prepared by mixing a copper etchant (Mitsubishi Gas Chemical, WLC-C2) and pure water in a 1:1 mass ratio. The copper and titanium layers were then removed by immersion for 10 minutes in a 23°C aqueous solution prepared by mixing a titanium etchant (Mitsubishi Gas Chemical Company, WLC-T) and a 23% aqueous ammonia solution in a mass ratio of 50:1. This procedure resulted in the formation of 20 sets of wiring, each consisting of 20 straight segments. The percentage of the 400 straight segments of the formed wiring that had been confirmed to have collapsed was calculated.If this ratio was between 80% and 100%, it was judged as "A", if this ratio was between 50% and less than 80%, it was judged as "B", and if this ratio was between 0% and less than 50%, it was judged as "C".

[0127] Wiring width variation Wiring was formed on the substrate in the same manner as in the evaluation of "fine wiring formability," except that the resist width / space width was changed to 5 μm / 5 μm. The cross section of the wiring was observed using a scanning electron microscope (Hitachi High-Technologies Corporation, SU8200 scanning electron microscope), and the width was measured at three arbitrary points on the wiring, and the standard deviation was calculated.

[0128] [Table 2] [Explanation of symbols]

[0129] 1...prepreg, 3...metal foil, 5...laminate, 10...insulating substrate, 11...inorganic fiber base material, 12...thermosetting resin composition, 100...substrate material for semiconductor package.

Claims

1. a step of increasing the temperature of a laminate having a metal foil, one or more prepregs, and a metal foil laminated in this order, to a heat press temperature while applying pressure to the laminate; a step of forming a substrate material having an insulating substrate formed from the prepreg and the metal foils provided on both sides of the insulating substrate by heating the laminate at a temperature equal to or higher than the heat press temperature while applying pressure to the laminate; in this order, the prepreg comprises an inorganic fiber substrate and a thermosetting resin composition impregnated into the inorganic fiber substrate, the content of the thermosetting resin composition being 40 to 80% by mass based on the mass of the prepreg; In the step of increasing the temperature of the laminate to the heat press temperature while pressing the laminate, the laminate is heated under heating conditions such that the minimum melt viscosity of the prepreg is 5000 Pa s or less. A method for manufacturing a substrate material for a semiconductor package.

2. The method according to claim 1, wherein the heating conditions are such that the minimum melt viscosity of the prepreg is 1000 Pa·s or more and 5000 Pa·s or less.

3. a step of increasing the temperature of the laminate to the heat press temperature while pressing the laminate, raising the temperature of the laminate to a holding temperature that is lower than the heat press temperature and within a range of ±20°C of the temperature at which the prepreg exhibits a minimum melt viscosity; Holding the laminate at the holding temperature for 5 to 90 minutes; increasing the temperature of the laminate from the holding temperature to the heat pressing temperature; 3. The method of claim 1 or 2, comprising, in this order:

4. A prepreg comprising an inorganic fiber substrate and a thermosetting resin composition impregnated into the inorganic fiber substrate, the content of the thermosetting resin composition is 40 to 80% by mass based on the mass of the prepreg, A prepreg having a minimum melt viscosity of 5000 Pa·s or less, measured at a temperature rise rate of 4°C / min.

5. The prepreg according to claim 4, which is used as a prepreg for producing a substrate material for a semiconductor package by the method according to any one of claims 1 to 3.

6. An application of the prepreg according to claim 4 to manufacture a substrate material for a semiconductor package by the method according to any one of claims 1 to 3.

7. A substrate material for a semiconductor package, comprising an insulating substrate having an insulating resin layer and an inorganic fiber base material provided in the insulating resin layer, the content of the insulating resin layer is 40 to 80 mass % based on the mass of the insulating substrate; The standard deviation of the thickness of the substrate material for semiconductor packages is 4 μm or less. Substrate material for semiconductor packages.

8. The substrate material for a semiconductor package according to claim 7 , further comprising metal foils provided on both sides of the insulating substrate.

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