JP2002145940A - Crosslinkable low relative dielectric constant polymer material and film, substrate and electronic part using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a low relative dielectric constant polymer material having excellent adhesivity or adhesiveness to a metal conductor layer, pattern formation ability by crosslinking, yet low relative dielectric constant and dielectric dissipation factor, excellent electrical insulating properties and excellent heat resistance. SOLUTION: This low relative dielectric constant polymer material is obtained by polymerizing a monomer composition comprising an epoxy group- containing fumaric acid diester as a monomer. A compound represented by general formula (II) and a compound represented by general formula (III) are suitable as the epoxy group-containing fumaric acid diester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel low dielectric polymer material having a pattern forming ability, and to a film, a substrate, and an electronic component using the same. More specifically, it has a low relative dielectric constant and a low dielectric loss tangent performance in electrical characteristics in a high frequency band, and has excellent heat resistance up to a high temperature range, excellent adhesion or adhesion to a metal foil, and a thin film pattern forming ability. The present invention relates to a dielectric polymer material.

[0002]

2. Description of the Related Art In recent years, with the rapid increase in the amount of communication information, there has been a strong demand for smaller, lighter, and faster communication devices, and low dielectric constant polymer materials that can cope with such demands have been demanded. In particular, the frequency band of radio waves used for portable mobile communications such as automobile telephones and digital portable telephones, and satellite communications has a high frequency band from megahertz to gigahertz. With the rapid development of communication devices used as these communication means, miniaturization and high-density mounting of substrates and electronic elements have been attempted. In order to reduce the size and weight of a communication device compatible with a high frequency band such as the megahertz to gigahertz band, it is necessary to develop an electrical insulating material having excellent high-frequency transmission characteristics. Furthermore, when trying to achieve high-density mounting,
As a method other than forming a multilayer laminate, a build-up method of stacking insulating layers requires a polymer material to be used to be capable of forming a pattern for forming a via hole in addition to electric characteristics.

As described above, materials having electrical characteristics such as electrical insulation and a low dielectric constant are usually thermoplastic resins such as polyolefins, chlorinated vinyl chloride resins and fluororesins, and unsaturated polyester resins. , Polyimide resin,
Thermosetting resins such as epoxy resins, vinyl triazine resins (BT resins), crosslinkable polyphenylene oxides, and curable polyphenylene ethers have been proposed. Further, as materials having pattern forming ability in addition to these electrical properties, photosensitive unsaturated polyester resin, photosensitive polyimide resin, photosensitive epoxy resin and the like have been proposed, but in practice, using photosensitive epoxy resin In general, photo-curing is used for pattern formation.

[0004] These materials having pattern forming ability have relatively good heat resistance. However, epoxy resins and unsaturated polyester resins have a relatively high relative dielectric constant of 3 or more, and satisfactory characteristics can be obtained. Not. On the other hand, the photosensitive polyimide resin has not reached a practical level.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide good adhesion or adhesion to a metal conductor layer, a pattern forming ability by cross-linking, and a low dielectric constant and a low dielectric loss tangent. An object of the present invention is to provide a low dielectric constant polymer material having excellent heat resistance and excellent heat resistance.

It is another object of the present invention to provide a substrate having excellent processing characteristics in which the low dielectric constant polymer material is coated or pasted on an insulating substrate and a pattern can be formed by crosslinking. Another object of the present invention is to provide an electronic component suitable for use in a high-frequency region obtained from the low dielectric constant polymer material.

[0007]

The polymer material of the present invention which achieves the above object has a low dielectric constant obtained by polymerizing a monomer composition containing an epoxy group-containing fumaric acid diester as a monomer. Polymer material.

In the low dielectric constant polymer material of the present invention, the epoxy group-containing fumaric diester is preferably a fumaric diester represented by the following formula (I).

[0009]

Embedded image More specifically, fumaric acid diesters represented by the following formulas (II) and (III) are preferred.

[0010]

Embedded image In the low dielectric constant polymer material of the present invention, the monomer composition may further include a fumarate ester monomer represented by the following formula (IV).

[0011]

Embedded image Here, R ³ in the formula represents an alkyl group or a cycloalkyl group, R ⁴ represents an alkyl group, a cycloalkyl group or an aryl group, and R ³ and R ⁴ may be the same or different.

[0012]

Embodiments of the present invention will be described below in detail.

The low dielectric constant polymer material of the present invention having a pattern forming ability by cross-linking is obtained by polymerizing a monomer composition containing an epoxy group-containing fumaric acid diester as a monomer. It is a fumarate polymer having a repeating unit derived from an epoxy group-containing fumaric acid diester.

The monomer of the epoxy group-containing fumaric acid diester (hereinafter, referred to as monomer α) may be one that imparts low dielectric constant and heat resistance to the polymer material when the polymer material is used. Although not particularly limited, fumaric diester represented by the above formula (I) can be mentioned as a preferred example.

The alkylene groups represented by R ¹ and R ² in the formula (I) may be linear or branched, and specifically include methylene, ethylene and trimethylene. Group, propylene group, tetramethylene group and the like. Note that R ¹ and R ² may be the same or different.

The alkylene oxides represented by A and B in the formula (I) are not essential, but examples include ethylene oxide and propylene oxide. Note that A and B may be the same or different.

Preferred examples of the monomer α represented by the formula (I) include diglycidyl fumarate (DGF) represented by the above formula (II) and dicyclohexylglycidyl represented by the above formula (III) Methanol fumarate (di-CHGM
F). These may be used alone or in combination of two or more.

The monomer composition may contain, as a monomer, another vinyl monomer (hereinafter, referred to as monomer β) in addition to the monomer α. That is, the polymer material of the present invention may be composed of a polymer composed of only the monomer α, or composed of a copolymer of the monomer α and the monomer β. Here, as the vinyl monomer of the monomer β, a fumarate ester monomer represented by the above formula (IV) is preferable.

The copolymer of monomer α and monomer β is
Any of a random copolymer, an alternating copolymer, and a block copolymer may be used. The mixing ratio of the monomer α and the monomer β is such that the monomer α is 50 to 100% by weight,
Is preferably 0 to 50% by weight. Monomer β is 5
Exceeding 0% by weight is not preferred because the heat resistance decreases and the water absorption increases. When the monomer β is copolymerized, flexibility is imparted.

The molecular weight of the low dielectric constant polymer material of the present invention is not particularly limited. However, when forming a build-up on an insulating substrate, since the insulating substrate itself has considerable mechanical strength, it cannot be supported. Some elements are used, and are not cross-linked and used after coating or adhesion, so that the mechanical strength is improved. Therefore, it is not necessary to be a high molecular weight substance as much as an insulating substrate, and it is sufficient if the molecular weight is such that a film can be formed, that is, the number average molecular weight is 1,000 or more.

In the present invention, in order to produce the above-mentioned fumarate-based polymer, a usual radical polymerization method can be used. As the polymerization initiator used in the polymerization,
It is necessary to avoid excessive heating from the viewpoint of protecting the epoxy group, and it is preferable to use one or more of an organic peroxide and an azo compound having a half-life temperature of 80 ° C. or less.

Examples of such a polymerization initiator include, for example,
Organic peroxides such as benzoyl peroxide, diisopropylperoxydicarbonate, t-butylperoxydi-2-ethylhexanoate, cumene peroxide, t-butyl hydroperoxide, 2,2′-azobisbutyronitrile, azobis Azo compounds such as (2,4-dimethylvaleronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), and 2,2′-azobis (2,4-dimethylvaleronitrile). The amount of the polymerization initiator to be used is preferably 10 parts by weight or less, more preferably 5 parts by weight, based on 100 parts by weight of the raw material monomer.
Not more than parts by weight.

The polymerization can be carried out according to a conventional method. Generally, in a solution polymerization method, an inert gas is used at a temperature in the range of 30 to 100 ° C., depending on the type of the polymerization initiator. By holding for 72 hours, a predetermined high molecular polymer is obtained.

Since the polymer material of the present invention thus obtained has a repeating unit derived from an epoxy group-containing fumaric acid diester, it has a pattern-forming ability by crosslinking, has a low dielectric constant, and has a low dielectric constant. Excellent in film properties, adhesion to metals, and mechanical properties.

The low dielectric constant polymer material of the present invention is formed by dissolving in an organic solvent, removing the solvent, and forming a film, whereby an electric insulating film or an electric insulating layer having good adhesion to a metal conductor can be easily and easily formed. It can be easily formed. At this time, if a ring-opening polymerization catalyst for an epoxy group is added to the organic solvent, the epoxy group can be cross-linked by heating or irradiation after film formation, and the mechanical properties can be further improved. In addition, when irradiating with radiation through a pattern film (photomask), the radiation-irradiated portions are crosslinked and the solvent solubility is greatly reduced. Can be formed.

The radiation that can be used here includes infrared rays, ultraviolet rays, electron beams, and the like. In consideration of exposure sensitivity and pattern line width, ultraviolet rays are generally used. Also,
As the polymerization initiation catalyst for the epoxy group, any catalyst capable of initiating polymerization by irradiation with radiation may be used.
Examples include photocationic polymerization catalysts such as diazonium, iodonium, metal complex, and aluminum complex / allyl cyanol.

The low dielectric constant polymer material of the present invention can be used in various forms such as a film, a coating film, and a bulk or molded article as described above.
Therefore, various substrates for electronic components such as high-frequency resonators, filters, capacitors, inductors, antennas, etc., filters as chip components (for example, C filters that are multilayer substrates) and resonators (for example, triplate resonators), It can be used for a support such as a dielectric resonator, a housing or a casing of various substrates or electronic components, or a coating thereof.

The film of the present invention may be a film obtained by forming a low dielectric constant polymer material by itself or a film obtained by impregnating glass fiber. As a method of forming a film by itself, after uniformly dissolving the polymer material in a solvent, casting is performed to obtain a uniform film by evaporating the solvent on a mold such as a glass plate, a silicone rubber plate, or a metal plate. Law. In the case of using glass fiber, a film can be obtained by impregnating the glass fiber with the solution of the low dielectric constant polymer material and then removing the solvent.

Examples of the substrate include an on-board substrate for mounting components, a copper-clad laminate, and the like.
It can also be used for an antenna substrate (for example, a patch antenna).

When an insulating substrate having a predetermined thickness is obtained from the above-mentioned film, the above-mentioned film may be laminated and dried in a residual solvent state so as to have a predetermined thickness. Thus, a substrate having a desired film thickness can be formed. At this time, it is also possible to perform pressure pressing if necessary. In that case, a multilayer substrate can also be formed by sandwiching a metal conductor layer such as copper between the films.

Since the low dielectric constant polymer material of the present invention has a pattern forming ability as described above, it is particularly suitable for use as a photosensitive layer in a laminate such as a copper-clad laminate. That is, the substrate of the present invention also includes a laminated plate provided with a metal layer such as copper on an insulating substrate and further provided thereon with a photosensitive layer made of the low dielectric constant polymer material.

[0032]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples.

(Synthesis Example 1) 10 parts by weight of diglycidyl fumarate (DGF) represented by the above formula (II) was placed in a glass ampule, and azobisisobutyronitrile (AIBN) 0.1 was used as a radical polymerization initiator. A weight part and further 1 weight part of purified benzene were taken in a glass ampoule, and then sufficiently replaced with nitrogen, depressurization and deaeration were repeated, and the ampule was sealed under vacuum. Next, this ampoule was placed in a constant temperature bath at 40 ° C. and kept for 72 hours. After the completion of the polymerization, the content liquid was poured into a large amount of methanol, and the polymer was separated by precipitation and dried under reduced pressure to obtain a target polymer.

(Synthesis Example 2) In Synthesis Example 1, dicyclohexylglycidylmethanol fumarate (di-CHGMF) represented by the above formula (III) is used instead of DGF.
Was used to obtain a polymer of dicyclohexylglycidylmethanol fumarate (di-CHGMF).

(Synthesis Example 3) Diglycidyl fumarate (D
GF) 5 parts by weight and diisopropyl fumarate (di
-IPF) using 5 parts by weight of diisopropyl peroxydicarbonate (IPP) as a radical polymerization initiator
Except that 0.01 parts by weight was used, the same as in Synthesis Example 1,
A copolymer of DGF / di-iPF was obtained.

Synthesis Example 4 Di-C was prepared in the same manner as in Synthesis Example 3 except that 7 parts by weight of dicyclohexylglycidylmethanol fumarate (di-CHGMF) and 3 parts by weight of dicyclohexyl fumarate (di-CHF) were used.
An HGMF / di-CHF copolymer was obtained.

(Comparative Synthesis Example 1) A di-iPF polymer was synthesized in the same manner as in Synthesis Example 1 except that 10 parts by weight of diisopropyl fumarate (di-iPF) was used.

(Comparative Synthesis Example 2) A di-CHF polymer was synthesized in the same manner as in Synthesis Example 1 except that 10 parts by weight of dicyclohexyl fumarate (di-CHF) was used.

Number average molecular weight Mn of each of the polymers and copolymers obtained in Synthesis Examples 1-4 and Comparative Synthesis Examples 1-2
Table 1 shows various properties.

(Example) 0.5 g of each polymer obtained in Synthesis Examples 1 to 4 and Comparative Synthesis Examples 1 and 2 was dissolved in 50 ml of benzene, and the polymerization initiator shown in Table 1 was added to solid content. 5% by weight was added. The obtained solution was poured into a smooth Petri dish having a diameter of about 20 cm, and then benzene was slowly evaporated to obtain a film. Then, using a high-pressure mercury lamp 80W x 1 lamp, the integrated illuminance 1000mj / c
The resin was irradiated with ultraviolet rays at m ^{2 and the} physical properties of the resin were measured thereafter. Table 1 shows the results.

[0041]

[Table 1]

As shown in Table 1, Synthesis Example 1 according to the present invention
The films formed of the polymer materials of Nos. To 4 have good adhesion to metal, excellent soldering heat resistance, and a frequency band of 1G.
In the high frequency band from 5 Hz to 5 GHz, the relative dielectric constant (ε) is 2.0 to 2.6 and the dielectric loss tangent (tan δ)
Was 0.0018 to 0.0042, which provided excellent electrical insulation.

[0043]

The low dielectric constant polymer material of the present invention is obtained by polymerizing a specific epoxy group-containing unsaturated dibasic acid diester monomer or a vinyl monomer with the monomer. And has excellent film-forming properties and heat resistance, as well as good adhesion or adhesion to the metal conductor layer. In addition, the dielectric constant and the dielectric loss tangent in the high frequency band from megahertz to gigahertz are low and the electrical insulation is excellent.

By using this low dielectric constant polymer material, an electric insulating film having good adhesion to a metal conductor can be easily and easily formed.
It is possible to obtain a multilayer substrate excellent in processing characteristics capable of forming a pattern, and to obtain an electronic component suitable for use in a high-frequency region.

Continued on the front page (72) Inventor Toshiaki Yamada 1-1-13 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Teruaki Sugawara 910-60 Ishidacho, Moriyama City, Shiga Prefecture (72) Inventor Naofumi Suzuki 280-93, Harimata-cho, Moriyama-shi, Shiga Prefecture F-term (reference) AC06 AC07 AF04 AG01 AH02 AH03

Claims (7)

[Claims] 1. A low dielectric constant polymer material obtained by polymerizing a monomer composition containing an epoxy group-containing fumaric acid diester as a monomer. 2. The low dielectric constant polymer material according to claim 1, wherein the epoxy group-containing fumaric acid diester is a fumaric acid diester represented by the following formula (I). Embedded image 3. The low dielectric constant of claim 1, wherein the epoxy group-containing fumaric diester is a fumaric diester represented by the following formula (II) and / or (III). Molecular material. Embedded image 4. The method according to claim 1, wherein the monomer composition further comprises the following formula (IV):
The low dielectric constant polymer material according to any one of claims 1 to 3, further comprising a fumaric acid ester monomer represented by the following formula: Embedded image (In the formula, R ³ represents an alkyl group or a cycloalkyl group, R ⁴ represents an alkyl group, a cycloalkyl group, or an aryl group, and R ³ and R ⁴ may be the same or different.) 5. A film comprising the low dielectric constant polymer material according to claim 1. 6. A substrate made of the low dielectric constant polymer material according to claim 1. 7. An electronic component using the low dielectric constant polymer material according to claim 1.