TW202030254A - Resin composition for millimeter wave substrate, adhesive film for millimeter wave substrate, millimeter wave substrate, millimeter wave radar substrate, and semiconductor device - Google Patents

Abstract

Provided is a resin composition for a millimeter-wave substrate which can be used as an insulator for a millimeter-wave radar, in which a cured product of the resin composition has excellent high-frequency characteristics, small temperature dependency of tan δ, and excellent flame retardancy.

This invention provides a resin composition for a millimeter-wave substrate including (A) a hydrogenated styrene elastomer, (B) a cross-linkable compound having a biphenyl skeleton, and (C) a flame retardant containing a metal salt of phosphinic acid, Component (C) is 15 parts by mass to 50 parts by mass with respect to 100 parts by mass in total of the components (A), (B) and (C), and the rate of change of the value of dielectric loss tangent at 10 GHz at 120 ℃ with respect to the value at 25 ℃ of the cured product is not more than 30%.

Description

Resin composition for millimeter wave substrate, adhesive film for millimeter wave substrate, millimeter wave substrate, millimeter wave radar substrate, and semiconductor device

The present invention relates to a resin composition for a millimeter wave substrate, an adhesive film for a millimeter wave substrate, a millimeter wave substrate, a millimeter wave radar substrate, and a semiconductor device.

In general, printed circuit boards for high-frequency applications are required to have low transmission loss. In the past, even in high-frequency applications, as long as the transmission loss in the 1GHz band is small, it is sufficient. However, the adhesive layer, cover layer, and substrate itself of the printed circuit board are used as an index of the degree of transmission loss. As long as the value of the electrical loss tangent (tan δ) is below 0.01, there is no problem. Therefore, even if the value of tan δ drifts more or less due to temperature changes, it can be accepted. For example, when the value of tan δ at room temperature is 0.0100 and the value at high temperature is 0.0110, the amount of change is 0.0010, and the rate of change of tan δ falls to 10%.

However, in recent years, the characteristics of the high frequency band above 3 GHz have become required. In order to reduce the transmission loss, a smaller value of tan δ has been sought, such as 0.003 or less. The value of tan δ only slightly changes, and the rate of change of tan δ will also increase. For example, when the value of tan δ at room temperature is 0.0030 and the value at high temperature is 0.0040, the amount of change is 0.0010, but the value of tan δ The rate of change increased to 33.3%. Therefore, a material with a small change rate of tan δ based on temperature change has become more necessary.

Especially in the case of the use of a millimeter-wave circuit substrate (hereinafter referred to as a millimeter-wave substrate), the rate of change of tan δ based on temperature changes in the high frequency band is small (that is, the temperature dependence of tan δ is small) The requirements are becoming more stringent. The same stringent requirements are imposed on millimeter-wave radars for vehicles that use substrates for millimeter-wave radars (hereinafter referred to as millimeter-wave radar substrates).

In addition, for substrate use, in addition to the small temperature dependence on tan δ, flame retardancy is further required. At this time, it becomes necessary to use a flame retardant, but it is currently based on a non-halogen (non-halogen) premise, so halogen-based flame retardants cannot be used.

Here, the "resin composition for a printed circuit board that has excellent dielectric properties in a high frequency band and small deviation of dielectric properties with respect to temperature changes, and exhibits excellent stability" (Patent Document 1, paragraph 0012, Paragraph 0015, etc.), it is disclosed that "a resin composition for a printed circuit board contains: a cyanate ester compound having two or more cyano groups in the molecule and/or these prepolymers, and An epoxy resin containing at least one type of epoxy resin having a biphenyl skeleton in its molecule" (Patent Document 1).

However, since the specific permittivity (ε) of this resin composition for printed circuit boards at 25°C is 3.5 or more, and the value of tan δ is as high as 0.004 or more, it is difficult even if the temperature dependence of tan δ is small. Used for millimeter wave substrate applications. In addition, the specifically disclosed flame retardants belong to halogen-based flame retardants.

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] JP 2010-212689 A

The present invention is made in view of the above circumstances and aims to provide a resin composition for millimeter wave substrates. The cured resin composition of the resin composition has excellent high-frequency characteristics, small temperature dependence of tan δ, and excellent flame retardancy, and can be used As an insulator for millimeter wave substrates.

The present invention relates to a resin composition for a millimeter wave substrate, an adhesive film for a millimeter wave substrate, a millimeter wave substrate, a millimeter wave radar substrate, and a semiconductor device that solve the above-mentioned problems by having the following configurations.

[1] A resin composition for millimeter wave substrates, comprising: (A) a hydrogenated styrene elastomer, (B) a crosslinkable compound having a biphenyl skeleton, and (C) a metal salt containing phosphonic acid Flame retardants, of which,

The (C) component is 15 to 50 parts by mass relative to 100 parts by mass of the total of (A) component, (B) component and (C) component;

The change rate of the dielectric loss tangent of the hardened material at 10GHz at 120°C to the value at 25°C is 30% or less.

[2] The resin composition for a millimeter wave substrate according to the above [1], wherein the phosphonic acid metal salt of the component (C) is 5 parts by mass or more.

[3] The resin composition for a millimeter wave substrate according to [1] or [2] above, wherein the dielectric loss tangent at 10 GHz is 0.0030 or less.

[4] The resin composition for a millimeter wave substrate according to any one of [1] to [3] above, wherein the (A) component is 100 parts by mass of the total of the (A) component and (B) component 50 to 80 parts by mass.

[5] The resin composition for a millimeter wave substrate according to any one of [1] to [4] above, wherein the component (A) is a styrene-ethylene/butylene-styrene block copolymer.

[6] An adhesive film for millimeter wave substrates, comprising the resin composition for millimeter wave substrates described in any one of [1] to [5] above.

[7] A millimeter wave substrate comprising a cured product of the resin composition for a millimeter wave substrate described in any one of [1] to [5] above.

[8] A millimeter wave radar substrate comprising a cured product of the resin composition for a millimeter wave substrate described in any one of [1] to [5] above.

[9] A semiconductor device comprising the millimeter wave substrate described in [7] above or the millimeter wave radar substrate described in [8] above.

According to the present invention [1], a resin composition for a millimeter wave substrate can be provided. The cured product of the resin composition has excellent high-frequency characteristics, small temperature dependence of tan δ, and excellent flame retardancy, and can be used as a millimeter wave Insulators for substrates.

According to the present invention [7], it is possible to provide a millimeter wave substrate having excellent high-frequency characteristics, small temperature dependence of tan δ, and excellent flame retardancy. According to the present invention [8], a millimeter wave radar substrate can be provided, which has excellent high-frequency characteristics, small temperature dependence of tan δ, and excellent flame retardancy.

According to the present invention [9], it is possible to provide a semiconductor device which is a highly reliable semiconductor device including a millimeter wave substrate or millimeter wave radar substrate with excellent high frequency characteristics, small temperature dependence of tan δ, and excellent flame retardancy (Hereinafter, also referred to as substrate).

Hereinafter, a suitable embodiment of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In addition, in this specification, the frequency domain (frequency domain) used for the millimeter wave substrate and the millimeter wave radar substrate refers to 3 GHz to 300 GHz.

〔Resin composition for millimeter wave substrate〕

The resin composition for millimeter wave substrates of the present invention (hereinafter referred to as the resin composition for substrates) contains (A) a hydrogenated styrene elastomer, (B) a crosslinkable compound having a biphenyl skeleton, and ( C) Flame retardant containing phosphonic acid metal salt, of which,

The (C) component is 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the total of (A) component, (B) component and (C) component,

The change rate of the dielectric loss tangent of the hardened material at 10GHz at 120°C to the value at 25°C is 30% or less.

The hydrogenated styrene-based elastic system belonging to the component (A) contributes to the properties and heat resistance of the film. In addition, it provides excellent electrical characteristics, low dielectric constant, and low dielectric loss tangent in the high frequency band. Furthermore, the temperature dependence of tan δ is small. In addition, since the component (A) has moderate flexibility that can relax the external stress of the resin composition for a substrate after curing, it can relax the stress generated in the substrate. (A) Component can include: styrene-ethylene/butylene-styrene block copolymer (SEBS), styrene-ethylene/propylene-styrene block copolymer (SEPS), styrene-(ethylene-ethylene/ From the viewpoint of heat resistance, propylene)-styrene block copolymer (SEEPS) is preferably styrene-ethylene/butylene-styrene block copolymer (SEBS). (A) The component is preferably one having a weight average molecular weight of 30,000 to 200,000. The weight average molecular weight is obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene. (A) A component may be used independently, and may use 2 or more types together.

As for the crosslinkable compound with biphenyl skeleton of component (B), the Tg of the cured product is high, so that the resin composition for the substrate after curing is not easy to change with time, and the long-term reliability of the substrate can be maintained Sex. In addition, the temperature dependence of tan δ is small. As for the cross-linkable compound having a biphenyl skeleton, a polyether compound having a phenyl group bonded with a vinyl group at both ends (hereinafter referred to as modified PPE), a compound having a biphenyl skeleton Epoxy and so on. Modified PPE and epoxy resins with a biphenyl skeleton have low moisture absorption and excellent moisture resistance because the number of hydrophilic groups in the resin is small. In addition, these compounds are excellent in insulating properties, and even if the thickness of the substrate formed of the resin composition for the substrate is reduced, the reliability of the substrate can be maintained.

As for the polyether compound having a phenyl group bonded with a vinyl group at both ends, a compound represented by the general formula (1) (hereinafter referred to as modified PPE) can be cited;

(In the formula,

R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , and R ₇ may be the same or different, and are hydrogen atoms, halogen atoms, alkyl groups, halogenated alkyl groups or phenyl groups,

-(OXO)- is represented by structural formula (2), wherein R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R ₁₅ may be the same or different, and are halogen atoms or alkyl groups with less than 6 carbon atoms or Phenyl, R ₁₁ , R ₁₂ , and R ₁₃ may be the same or different, and are hydrogen atoms, halogen atoms, or alkyl groups or phenyl groups with less than 6 carbon atoms,

-(YO)- is a structure shown in structural formula (3), or two or more structures shown in structural formula (3) are arranged randomly, wherein R ₁₆ and R ₁₇ can be the same or different, And it is a halogen atom or an alkyl group or phenyl group with a carbon number of 6 or less, R ₁₈ and R ₁₉ may be the same or different, and are hydrogen atoms, a halogen atom, or an alkyl group or a phenyl group with a carbon number of 6 or less,

Z is an organic group with a carbon number of 1 or more, and optionally includes oxygen, nitrogen, sulfur, and halogen atoms,

a, b show at least one of the integers from 0 to 300 that is not 0,

c, d show an integer of 0 or 1).

Regarding the -(OXO)- structural formula (2) of the modified PPE represented by the general formula (1), R ₈ , R ₉ , R ₁₀ , R ₁₄ , and R _{15 are} preferably alkyl groups with 3 or less carbon atoms , R ₁₁ , R ₁₂ , and R _{13 are} preferably a hydrogen atom or an alkyl group with 3 or less carbon atoms. Specifically, structural formula (4) can be cited.

Regarding the structural formula (3) of -(YO)-, R ₁₆ and R _{17 are} preferably an alkyl group having 3 or less carbon atoms, and R ₁₈ and R _{19 are} preferably a hydrogen atom or an alkyl group having 3 or less carbon atoms. Specifically, structural formula (5) or (6) can be cited.

Examples of Z include an alkylene group having 3 or less carbon atoms, and specifically a methylene group.

a and b show at least one of the integers from 0 to 300 that is not 0, preferably an integer from 0 to 30.

Preferably, it is a modified PPE of general formula (1) with a number average molecular weight of 1,000 to 4500. More preferably, the number average molecular weight is 1,000 to 3,000. The above-mentioned modified PPE can be used alone or in combination of two or more.

From the viewpoints that the adhesive strength of the resin composition for a substrate is improved and the temperature dependence of tan δ is reduced compared to epoxy resins of other structures, an epoxy resin having a biphenyl skeleton is preferred. In addition, it is preferably one that does not contain a hydroxyl group in the molecule having an epoxy equivalent of 150 to 300. However, the epoxy resin having a biphenyl skeleton may not be included. In some aspects, the resin composition for a substrate does not substantially contain epoxy resin.

The component (B) preferably further contains an initiator or a hardening agent. Examples of the initiator for the modified PPE include organic peroxides, and examples of the hardeners for epoxy resins having a biphenyl skeleton include phenol hardeners, amine hardeners, imidazole hardeners, and acid anhydride hardeners. Wait. In particular, from the viewpoint of reducing the temperature dependence of tan δ on the curability and adhesiveness of an epoxy resin having a biphenyl skeleton, an imidazole-based curing agent is preferred. (B) The component may be used alone, or two or more of them may be used in combination.

On the metal phosphinate-containing flame retardant component (C) in terms of, based include _{^{M e (POOR 20 R 21)}} f ( the formula, M is Li, Na, K, Mg, Ca, Sr, Ba, Al, Ge, Sn, Sb, Bi, Zn, Ti, Zr, Mn, Fe or Ce, R ²⁰ and R ²¹ are aliphatic hydrocarbon groups or aromatic nicotine groups with 1 to 5 carbon atoms, and e and f are 1 Up to 9). Among these, from the viewpoint of flame retardancy and the viewpoint of reducing the temperature dependence of tan δ, aluminum phosphonate is preferred, aluminum dialkylphosphonate is more preferred, and diethyl phosphine is more preferred. Acid aluminum.

The flame retardants that can be used other than the phosphonic acid metal salt as the component (C) include flame retardants that are halogen-free and have a small temperature dependence of tan δ. Specifically, examples include: bisphenol bis(xylenyl) phosphate, 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide Wait. (C) A component may be used individually or in combination of 2 or more types.

The (A) component is preferably 50 to 80 parts by mass, more preferably 55 to 80 parts by mass with respect to 100 parts by mass of the total of (A) component and (B) component. When the content of the (A) component is greater than or equal to the content of the (B) component, the peel strength of the resin composition for a substrate is likely to increase, and the heat resistance reliability (for example, at 125° C., 1000 hours or more) is easily improved.

In addition, with respect to 100 parts by mass of the total of (A) component, (B) component and (C) component, (A) component is preferably 32.5 to 70 parts by mass, more preferably 40 to 70 parts by mass, and still more preferably 40 to 64 parts by mass.

From the viewpoint of imparting flame retardancy and high-frequency characteristics, the (C) component is 15 to 50 parts by mass relative to 100 parts by mass of the total of the (A) component, (B) component, and (C) component.

Here, when the (C) component is only the phosphonic acid metal salt, the phosphonic acid metal salt is 20 to 35 parts by mass relative to the total of 100 parts by weight of the (A) component, (B) component and (C) component Better.

When the (C) component is composed of a phosphonic acid metal salt and other flame retardants, from the standpoint of flame retardancy, high frequency characteristics, adhesiveness, and heat resistance, it is relative to the (A) component. The total of component (B) and component (C) is 100 parts by mass, phosphonic acid metal salt is more than 5 parts by mass but less than 15 parts by mass, and other flame retardants are 20-40 parts by mass, and belong to the flame retardant of component (C) The total amount of the agents is preferably 25 to 50 parts by mass.

In addition, the resin composition for substrates may contain inorganic fillers, silane coupling agents, defoamers, dispersion aids, antioxidants, defoamers, and conditioning agents within a range that does not impair the effects of the present invention. Additives such as leveling agents, thixotropic agents, anti-blooming agents, anti-caking agents and organic solvents.

From the viewpoint of improving the physical properties of the cured product, general inorganic fillers can be used as the inorganic filler. In terms of low thermal expansion coefficient, SiO _{2 is} preferred; in terms of obtaining desired hardened physical properties, it is preferably selected from talc, kaolin, BaSO ₄ , CaCO ₃ , MgO, Al ₂ O ₃ , At least one inorganic filler selected from the group consisting of SiO ₂ , AlN, BN, diamond filler, ZnO, and SiC. These fillers can be surface treated.

The average particle diameter of the inorganic filler (the average maximum particle diameter in the case of non-granular form) is not particularly limited, but in order to reduce the moisture resistance of the cured resin due to the moisture absorption on the surface of the filler particles, and obtain the The desired thickness of the coating film is therefore preferably 0.05 to 20 μm. When the average particle size of the inorganic filler is less than 0.05 μm, the moisture absorption on the surface of the inorganic filler increases due to the large specific surface area, and the moisture resistance of the cured resin may deteriorate. If it exceeds 20 μm, the thickness of the coating film is too large for the necessary thickness, and it may be difficult to obtain the desired thickness. Furthermore, when used in a finely patterned substrate, since the filler is too large relative to the size of the pattern, the filler material and resin on the pattern may be localized, which may increase the dielectric loss. The average particle size of the inorganic filler is more preferably 1 to 10 μm, and more preferably the maximum particle size is 10 μm or less. By setting the maximum particle size to 10 μm or less, it becomes easy to prevent the dielectric loss from increasing in the frequency band above 10 GHz. Here, the average particle size and maximum particle size of the inorganic filler are measured by a laser scattering diffraction type particle size distribution measuring device. The inorganic filler may be used alone, or two or more of them may be used in combination.

Examples of organic solvents include aromatic solvents, such as toluene, xylene, etc.; ketone solvents, such as methyl ethyl ketone, methyl isobutyl ketone, etc.; in addition, cyclohexanone, two High boiling point solvents such as methylformamide and 1-methyl-2-pyrrolidone. The organic solvent may be used alone or in combination of two or more. In addition, the amount of the organic solvent used is not particularly limited, as long as it can be adjusted so as to achieve the respective preferred viscosity according to the coating method of the resin composition. Specifically, an organic solvent can be used so that the solid content becomes 20 to 80% by mass.

The resin composition for a substrate can be obtained by dissolving or dispersing raw materials containing components (A) to (C) in an organic solvent. The device for dissolving or dispersing these raw materials is not particularly limited, but a stirrer, dissolver, crusher, three-roll mill, ball mill, planetary mixer, bead mill, etc., equipped with a heating device can be used . Moreover, these devices can be used in appropriate combination.

The resin composition for a substrate can be thermally cured at 130 to 220°C for 30 to 180 minutes, for example. The resin composition for a substrate can be appropriately selected to have a viscosity of 0.1 to 100 Pa•s in accordance with the desired coating method, and the viscosity is a value measured at 10 rpm and 25° C. using an E-type viscometer.

Regarding the tan δ of the cured product at 10 GHz, the resin composition for a substrate has a rate of change of 30% or less at a value at 120°C to a value at 25°C. When the change rate of tan δ at 10GHz at 120°C to 25°C is greater than 30%, it cannot meet market requirements. The change rate of the value of tan δ at 10GHz at 120°C relative to the value at 25°C is preferably 20% or less, more preferably 10% or less.

From the viewpoint of the use of the resin composition for a substrate in its frequency band, the dielectric loss tangent of the resin composition for a substrate at 10 GHz is preferably 0.0030 or less. The resin composition system for a substrate can be used for an adhesive layer, a cover layer, or the substrate itself of a circuit board.

〔Products using resin composition for millimeter wave substrate〕

The adhesive film for millimeter wave substrates of the present invention includes the above-mentioned resin composition for millimeter wave substrates. The adhesive film for a millimeter wave substrate can be formed from a resin composition for a substrate.

The adhesive film for a millimeter wave substrate can be obtained by coating the resin composition for a substrate on a desired support, and then drying it. The support is not particularly limited, and examples include metal foils such as copper and aluminum; organic films such as polyester resins, polyethylene resins, and polyethylene terephthalate resins. The support can be released by polysiloxane compounds.

The method of applying the resin composition for a substrate to the support is not particularly limited, but in terms of thinning/controlling the film thickness, a microgravia method or a slot die coating is preferable. ) Method, doctor blade method. By the slit die coating method, an adhesive film for a millimeter wave substrate having a thickness of 10 to 300 μm after thermal curing can be obtained.

The drying conditions can be appropriately set according to the type and amount of the organic solvent used in the resin composition for the substrate, the thickness of the coating, and the like. For example, it can be performed at 50 to 120°C for about 1 to 30 minutes. The insulating adhesive film for millimeter wave substrates obtained in this way has good storage stability. In addition, the adhesive film system for a millimeter wave substrate can be peeled from the support at a desired timing.

The adhesive film for the millimeter wave substrate can be thermally cured at 130 to 220° C. for 30 to 180 minutes, for example.

The thickness of the adhesive film for a millimeter wave substrate is preferably 10 μm or more and 300 μm or less, and more preferably 20 μm or more and 200 μm or less. When it is less than 10μm, it may become impossible to obtain The desired insulation, the strength of the coating film, and the durability. When it exceeds 300 μm, the stress during hardening will increase, and the substrate may be warped and other defects.

The millimeter wave substrate of the present invention is a cured product containing the resin composition for the millimeter wave substrate described above. That is, the cured product includes the adhesive film for millimeter wave substrates described above.

The millimeter wave radar substrate of the present invention is a cured product containing the resin composition for the millimeter wave substrate described above. That is, the cured product includes the adhesive film for millimeter wave substrates described above.

The semiconductor device of the present invention includes the millimeter wave substrate described above or the millimeter wave radar substrate described above.

[Example]

The present invention is explained by examples, but the present invention is not limited to these examples. In addition, in the following examples, parts and% refer to parts by mass and% by mass unless otherwise stated.

The raw materials used in the examples/comparative examples described in Table 1 to Table 3 are as follows.

G1652MU: Hydrogenated styrene elastomer SEBS made by Kraton polymer

OPE-2St 2200: Styrene end-modified PPE oligomer manufactured by Mitsubishi Gas Chemical (Molecular Weight: Mn2200)

YX4000HK: Biphenyl skeleton epoxy resin manufactured by Mitsubishi Chemical

OP935: Aluminum diethyl phosphonate (aluminum phosphonate) made by clariant chemicals shown in the chemical formula below:

KBE-846: Silane coupling agent bis(triethoxysilylpropyl) tetrasulfide manufactured by Shin-Etsu Chemical

KBM-573: Silane coupling agent N-phenyl-3-aminopropyl trimethoxysilane manufactured by Shin-Etsu Chemical

PERCUMYL D: Organic peroxide bis-isophenylpropyl peroxide made by Japan Oil

EH-2021: Modified imidazole made by ADEKA

FB-3SDX: spherical silica filler made by denka (average particle size: 3.4μm)

PX-200: Dihydroxybenzene bis-bis(xylenyl) phosphate shown in the chemical formula below:

PX-202: Bisphenol bis-bis(xylyl) phosphate produced by Daha Chemical Industry as shown in the following chemical formula:

TPP: Triphenyl phosphate produced by Dahachi Chemical Industry as shown in the following chemical formula:

FP-600: Bisphenol A bis-diphenyl phosphate produced by ADEKA shown in the following chemical formula:

FP-100: Phenoxy cyclophosphazene produced by Fushimi Pharmaceutical as shown in the following chemical formula:

HCA-HQ-HS: 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10-phosphaphenanthrene-10-oxide produced by Sanko, shown in the following chemical formula:

HCA: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide produced by Sanko, shown in the following chemical formula:

TR2003: Non-hydrogenated styrene elastomer SBS manufactured by JSR

[Examples 1 to 9, Comparative Examples 1 to 11]

After measuring each component according to the formula (parts by mass) shown in Tables 1 to 3, put the (A) component or (A') component, and (B) component in the heating mixer with a predetermined amount of toluene first, and Rotate the stirring blade at a speed of 35 rpm at 70°C and normal pressure while dissolving and mixing for 2 hours Together. Then, after cooling to normal temperature, the (C) component or (C') component, and other components were added, and the stirring blade was rotated at 60 rpm while stirring and mixing for 1 hour. Next, in the stirring material, a predetermined amount of toluene is added so as to have a viscosity suitable for coating, followed by stirring and dilution. After that, a wet micronizer (manufactured by Yoshida Machinery Co., Ltd., model: nanomizer MN2-2000AR) was used to disperse the resin composition.

The coating solution containing the resin composition obtained in this way was coated on one side of the support (PET film subjected to release treatment) and dried at 100°C, thereby obtaining a millimeter with a support Adhesive film for wave substrates (thickness 100μm).

〔1. Fire resistance evaluation〕

Test according to UL94 VTM burning test method, and judge the flame retardancy. The resulting adhesive film for millimeter-wave substrates was heated and cured at 200°C×60 minutes and 10 kgf, peeled from the support, and cut into a size of 200±5 mm in length×50±1 mm in width to prepare a test piece. Set the 50mm side of the test piece as the bottom edge, and draw a marker line along the width at a position 125mm from the bottom edge with a pen, and press the rod (rod diameter: 12.7±0.5mm) against the test piece Wrap the test piece in the length direction of the test piece, and after attaching the pressure-sensitive tape to the part above the marking line, pull out the rod, and use the pressure-sensitive tape on the upper end of the tube-shaped test piece in a way that does not produce a chimney effect Be closed. The upper end of the test piece is clamped with a clamp set on the stand, and the test piece is kept vertical. Ignite a Bunsen burner with an inner diameter of 9.5±0.3mm (0.374±0.012 inches), and adjust the flame so that the flame becomes a yellow-free blue flame and the height becomes 19mm: (3/4 inch). The flame is set up so that the distance between the center of the lower end of the cylindrical test piece and the opening of the lamp becomes 9.5mm (3/8 inch), and the flame is connected for the first time for 3±0.5 seconds. Burning time (including fire Kind of time). Immediately after the fire is extinguished, carry out the second flame connection for 3±0.5 seconds, then remove it, and measure the burning time (including the fire time). For each of the Examples and Comparative Examples, the test was performed with 5 test pieces, and those satisfying the judgment conditions of VTM-0 as shown below were judged to be equivalent to VTM-0 and regarded as pass. The result was marked with VTM-0. The equivalent is set to "○" and the one that is not equivalent to VTM-0 is set to "×".

<VTM-0 Judgment Conditions>

(1) The burning time after the first flame release or the second flame release of each test piece is 10 seconds or less.

(2) The total of the first burning time and the second burning time of the five test pieces is 50 seconds or less.

(3) The total burning time after the second flame release is 30 seconds or less.

(4) The combustion does not reach the mark line.

(5) There is no ignition of absorbent cotton (installed under the test piece) caused by falling objects during burning.

※However, because there is no falling material during burning, it does not focus on the fire of absorbent cotton.

[2. Evaluation of specific permittivity (ε) and dielectric loss tangent (tan δ)]

After peeling the adhesive film for the millimeter wave substrate from the support, laminate it so that the thickness becomes about 1mm, and heat and harden it at 200°C×60 minutes, 10kgf, so that the width: about 1mm, the length: about 20mm Cut to make a rod-shaped test piece. The size of the test piece was measured, and the specific permittivity (ε) and the dielectric loss tangent (tan δ) at 25°C at 10 GHz were measured with a cavity resonator in a precision thermostat. Preferably, the specific permittivity is 3.5 or less, and the dielectric loss tangent is 0.003 or less.

[3. Evaluation of temperature dependence (temperature characteristics) of specific permittivity (ε) and dielectric loss tangent (tan δ)]

In a precision constant temperature bath heated to 120°C, using a cavity resonator, measure [2. Evaluation of specific permittivity (ε) and dielectric loss tangent (tan δ)] at 10 GHz Specific permittivity (ε) and dielectric loss tangent (tan δ) at 120°C. From this value, the percentage of change relative to the measured value at 25°C was obtained. The rate of change is preferably ±30% or less.

[4. Evaluation of peel strength]

Copper foil (CF-T9FZSV, manufactured by Futian Metal Foil & Powder Industry Co., Ltd., thickness: 18μm) is bonded to both sides of the adhesive film for millimeter wave substrates with the roughened surface as the inner side, using a rolling mill at 200℃×60 It is hardened by applying pressure at 30kgf. The test piece was cut to a width of 10 mm, and peeled off from the interface of the copper foil with a precision universal testing machine (Autograph), and the peel strength of 180° was measured (according to JISK6854-2). Take the average value of n=5 as the measured value. The peel strength is preferably 4.5 (unit: (N/cm)) or more.

[5. Evaluation of solder heat resistance]

The copper foil was affixed and cured in the same manner as in [4. Evaluation of Peeling Strength] and cut to 30×30 mm to prepare test pieces. This was placed on the surface of a solder bath heated to 260°C for 60 seconds, and the presence of swelling protrusions was visually observed. The test was carried out with n=3, and those without swelling protrusions were set as "○", and those with swelling protrusions were set as "×".

Tables 1 to 3 show the preparation and evaluation results of the examples/comparative examples. In Tables 1 to 3, the filler ratio is relative to the volume ratio (Vol%) of the silica filler excluding all components of toluene, the specific gravity of the silica filler is set to 2.2, and the specific gravity of other components is set to 1.0 And the figure out. In addition, the elastomer ratio is the mass ratio (%) of the (A) component with respect to 100 parts by mass of the total of the (A) component and the (B) component. The formulation was based on Example 1. In Example 1, the ratio of the (A) component: (B) component relative to the total 100 parts by mass of the (A) component and the (B) component was 65:35, and compared with the (A) component, (B) The blending amount of the (C) component of 100 parts by mass of the total of the component and the (C) component is set to 30 parts by mass, and the blending ratio of the silica filler is set to 227 parts by mass so that the blending ratio of the silica filler becomes 50 vol% (vol%), And use KBE-846 (thioether series) as silane coupling agent. Example 2 is based on the formula of Example 1 without the silica filler. Example 3 will phase The blending amount of (C) component for the total of 100 parts by mass of (A) component, (B) component and (C) component is set to 20 parts by mass, and part of (B) component is replaced with biphenyl skeleton epoxy Resin. (A) Component: The ratio of (B) component is 60:(35:5). In Example 4, the blending amount of the (C) component with respect to the total of 100 parts by mass of the (A) component, (B) component, and (C) component was 50 parts by mass. In Example 5, the compounding amount of the (C) component with respect to the total of 100 parts by mass of the (A) component, (B) component, and (C) component was 15 parts by mass. In Example 6, the blending amount of the (C) component with respect to the total 100 parts by mass of the (A) component, (B) component and (C) component was 20 parts by mass, and the (A) component: (B) component The ratio is set to 80:20. In Example 7, the compounding amount of the (C) component with respect to the total of 100 parts by mass of the (A) component, (B) component and (C) component was 20 parts by mass, and the (A) component: (B) The ratio of ingredients is set to 55:45. In Example 8, the blending amount of the (C) component with respect to the total of 100 parts by mass of the (A) component, (B) component and (C) component was set to 20 parts by mass, and the silane coupling agent belonging to other components was changed It is KBM-573 (amine-based). Example 9 is a combination of two (C) flame retardants. In more detail, the blending amount of (C) component relative to the total of (A) component, (B) component and (C) component 100 parts by mass is 45 parts by mass, and 5 mass parts of phosphonic acid metal salt An example in which parts are combined with 40 parts by mass of another flame retardant (HCA-HQ-HS).

It can be seen from Table 1 that the flame retardancy of Examples 1 to 9 are all equivalent to VTM-0, and the temperature dependence of ε and ε is low, the temperature dependence of tan δ and tan δ is also small, the peel strength is high, and the solder heat resistance The performance is high, and the result is good.

As can be seen from Table 2, Comparative Examples 1 to 7 are those in which the component (C) of Example 1 is replaced with another phosphorus-based flame retardant ((C') component) of the same content. In terms of flame retardancy, all of Comparative Examples 1 to 7 could not achieve VTM-0, which was inferior to Example 1. However, the tan δ of Comparative Example 2 using PX-202 and Comparative Example 6 using HCA-HQ-HS is small at 25°C, and the temperature characteristics are also good (temperature dependent Little reliance). However, the temperature characteristics of Comparative Example 1, Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 7 are very poor (large temperature dependence). Furthermore, the tan δ of Comparative Example 3, Comparative Example 4, and Comparative Example 5 The value at 25°C exceeds 0.003, which means it cannot be used for millimeter wave substrate applications. In addition, the peel strength of Comparative Example 4 and Comparative Example 7 was low.

As can be seen from Table 3, in Comparative Example 8, when the component (A) of Example 1 was replaced with a non-hydrogenated styrene elastomer (component (A')), the temperature characteristic of tan δ was poor (large temperature dependence). Comparative Example 9 is based on the blending amount of the component (C) of Example 1 at 55 parts by mass relative to the total of the components (A), (B) and (C) 100 parts by mass, and the solder heat resistance is compared It is worse in Example 1, and the peel strength is also lower. In Comparative Example 10, when the blending amount of the component (C) of Example 1 is 10 parts by mass relative to the total of 100 parts by mass of the (A) component, (B) component and (C) component, the flame retardancy is not good Achieve VTM-0. In Comparative Example 11, the component (C) was removed from Example 1, and the flame retardant was not blended, and the flame retardancy failed to achieve VTM-0. On the other hand, the temperature characteristics are good (the temperature dependence is small).

As described above, the resin composition for millimeter wave substrates of the present invention has excellent high-frequency characteristics of the cured resin composition, small temperature dependence of tan δ, and excellent flame retardancy, and can be used as an insulation for millimeter wave radars. The body is very useful in the manufacture of highly reliable millimeter wave substrates, millimeter wave radar substrates, and semiconductor devices.

Claims (9)

A resin composition for millimeter wave substrates, comprising: (A) hydrogenated styrene elastomer, (B) crosslinkable compound with biphenyl skeleton, and (C) flame retardant containing phosphonic acid metal salt ； Wherein, the (C) component is 15 to 50 parts by mass relative to 100 parts by mass of the total of (A) component, (B) component and (C) component; The change rate of the dielectric loss tangent of the hardened material at 10GHz at 120°C to the value at 25°C is 30% or less. The resin composition for millimeter-wave substrates as described in claim 1, wherein the phosphonic acid metal salt of the component (C) is 5 parts by mass or more. The resin composition for millimeter wave substrates as described in item 1 or 2 of the scope of patent application, wherein the dielectric loss tangent at 10 GHz is 0.0030 or less. The resin composition for millimeter wave substrates according to any one of the claims 1 to 3, wherein the (A) component is 50 to 100 parts by mass of the total of the (A) component and (B) component 80 parts by mass. The resin composition for a millimeter wave substrate according to any one of the claims 1 to 4, wherein the component (A) is a styrene-ethylene/butylene-styrene block copolymer. An adhesive film for millimeter wave substrates contains the resin composition for millimeter wave substrates described in any one of items 1 to 5 in the scope of patent application. A millimeter wave substrate is a cured product containing the resin composition for millimeter wave substrates described in any one of the first to fifth patent applications. A millimeter-wave radar substrate is a cured product containing the resin composition for millimeter-wave substrates described in any one of items 1 to 5 in the scope of patent application. A semiconductor device containing the millimeter wave substrate described in the 7th patent application or the millimeter wave radar substrate described in the 8 patent application.