JP2001151935A - Resin composition for circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preferable resin composition for a circuit board as a circuit board material of electronic equipment due to a low linear expansion coefficient, a low specific permittivity, a low dielectric dissipation factor, a high heat resistance, and high mechanical strengths. SOLUTION: The resin composition for a circuit board comprises compounding a scaly inorganic filler having a specific permittivity of <=8 at 1 MHz and a dielectric dissipation factor of <=0.004 with a synthetic resin having a melting temperature of 300 deg.C<=.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a circuit board, and more particularly to an electronic device having a low coefficient of linear expansion, a low dielectric constant, a low dielectric loss tangent, a high heat resistance, and a high mechanical strength. The present invention relates to a resin composition for a circuit board suitable as a material for a circuit board.

[0002]

2. Description of the Related Art Materials for circuit boards of electronic equipment have low dielectric properties such as relative permittivity and dielectric loss tangent, and have a coefficient of linear expansion, heat resistance, and the like.
It is required to have excellent physical properties such as mechanical strength.
The relative permittivity (ε) is a parameter indicating the degree of polarization in a dielectric, and the higher the relative permittivity, the larger the propagation delay of an electric signal (Td = 3.3√ε, Td; electrical signal propagation delay) time). Therefore, in order to increase the signal propagation speed and enable high-speed operation, it is preferable that the relative dielectric constant is low.
The dielectric loss tangent (tan δ) is a parameter indicating the amount of a signal propagating in a dielectric which is converted into heat and lost.
The lower the dielectric loss tangent, the smaller the signal loss and the higher the signal transmission rate.

Conventionally, as a circuit board material, a so-called "glass epoxy board" obtained by impregnating and curing a thermosetting resin such as an epoxy resin in a glass cloth has been generally used.
Its dielectric constant is as high as 4.5 to 5.5, and its dielectric loss tangent is also 0.5.
Since it is as large as 020 to 0.035, the transmission speed and the transmission rate of the signal in a high frequency range of the MHz band or more are not satisfactory.

[0004] For the purpose of improving the linear expansion coefficient, heat resistance, mechanical strength, and the like, it is common practice to add various whiskers or reinforcing fibers such as fibrous materials to synthetic resins for electronic members. For example, according to JP-A-3-35585, glass fibers, potassium titanate whiskers and the like are proposed as such reinforcing fibers.

However, when glass fiber is added to a synthetic resin, the rise in relative dielectric constant can be suppressed relatively small,
The dielectric loss tangent increases significantly. Further, the glass fiber is as thick as 5 to 15 μm in fiber diameter and as long as 100 μm or more in fiber length, so that the surface smoothness of the molded product is impaired and it becomes difficult to plate a fine circuit on the surface of the molded product. In addition, when connecting circuits with a wire bonder, the tip of the wire bonder may be damaged.

[0006] Potassium titanate whiskers are microfibers having a fiber diameter of 0.05 to 2 µm and a fiber length of 2 to 50 µm, and are effective in improving heat resistance, mechanical strength, and decreasing the linear expansion coefficient. , The relative dielectric constant and the dielectric loss tangent are significantly increased, resulting in a delay in signal transmission speed and a decrease in transmission efficiency. In addition, the alkaline components such as potassium contained in the whiskers corrode the electrodes and wirings of the electronic device, cause disconnection, current leakage, and the like.

On the other hand, a thermoplastic resin composition comprising a heat-resistant resin and an inorganic filler, having good heat resistance, mechanical strength, electric insulation and moldability, and suitable as a material for electronic members has been proposed. (Japanese Patent Application Laid-Open No. 62-149436, etc.). However, general inorganic fillers do not have a stable particle size distribution and irregular shape, so when a thin substrate such as a film is manufactured, the surface properties may be roughened or extremely brittle. turn into.

[0008]

DISCLOSURE OF THE INVENTION The present invention does not have the above problems, and has a low relative dielectric constant, a low coefficient of linear expansion, a high heat resistance,
It is an object of the present invention to provide a resin composition for a circuit board which has both high mechanical strength and is suitable as a circuit board material for an electronic device.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the melting temperature is 300 ° C.
By mixing a specific flaky inorganic compound with a resin composition composed of a synthetic resin having a temperature of not less than ℃, without an increase in the relative dielectric constant that hinders use in a high-frequency range,
In addition, the present invention has found that heat resistance and mechanical strength can be improved, and that it does not curl when laminated with a metal foil as a circuit board, and that a highly desirable composition as a material for electronic members can be obtained. Was completed.

That is, according to the present invention, the melting temperature is 300 ° C.
The gist of the present invention is a resin composition for a circuit board, characterized in that a flake-like inorganic compound having a relative dielectric constant of 8 or less at 1 MHz and a dielectric loss tangent of 0.004 or less is mixed with the above synthetic resin. I do. The values of the relative permittivity and the dielectric loss tangent in this specification are 1 MHz, 2
The value is measured under the condition of 5 ° C.

The synthetic resin used in the present invention having a melting temperature of 300 ° C. or higher can be used without any particular limitation.
For example, there are polyallyl ether ketone, polyether sulfone, polysulfone, polyether imide, liquid crystal polymer, thermoplastic polyimide, polyarylate, polyether nitrile, polyphenylene sulfide, polyphenylene ether, polyamide imide and the like. Preferably, polyallyl ether ketone, polyether imide,
Liquid crystal polymer and thermoplastic polyimide are good. These resins can be used alone or in combination with one or more other resins.

The scaly inorganic compound used in the present invention comprises:
Examples include synthetic mica, mica, sericite, illite, talc, kaolinite, montmorillonite, smectite, and vermiculite. More preferably, synthetic mica and mica are good. These flaky inorganic compounds may be subjected to surface treatment with various coupling agents.

The amount of the flaky inorganic compound in the composition of the present invention can be appropriately selected from a wide range according to the type of a circuit board to which the obtained composition of the present invention is applied. The amount may be about 5 to 100 parts by weight, preferably about 10 to 50 parts by weight, per 100 parts by weight of a certain synthetic resin.

The composition of the present invention may contain ordinary additives for synthetic resins as long as the preferable properties are not impaired. Specific examples of the additive include a flame retardant, a flame retardant auxiliary, an ultraviolet absorber, an antioxidant, a solid or liquid lubricant, an impact resistance agent, a dye, a pigment, and the like.

The composition of the present invention can be produced by mixing a predetermined amount of each component with a usual mixing device such as a mixing mixer having a heating function and a mixing function, a single-screw or twin-screw extruder, or the like. .

[0016]

The present invention will be specifically described below with reference to examples and comparative examples. (Examples 1 to 9 and Comparative Examples 1 to 7) Each component is shown in Tables 1 and 2.
At a predetermined ratio (parts by weight) as shown in the following table, and supplied to a twin-screw extruder (Kobe Steel, Ltd .; KTX46) to obtain a pellet-shaped resin composition.

A test piece was prepared from the obtained pellet composition by injection molding. 1M of the obtained test piece
The relative permittivity and the dielectric loss tangent at hz and 3 Ghz were measured. The relative permittivity and dielectric loss tangent at 1 MHz are JIS
According to K6911, the relative permittivity and the dielectric loss tangent at 3 Ghz were measured by a cavity resonance method using a network analyzer 8719C (manufactured by Hewlett-Packard Company). The results are also shown in Table 1.

1. PEEK (polyetheretherketone);
Victrex; 450G 2.PEI (polyetherimide); GE Plastics Japan; Ultem 1000-1000 3.PAR (polyarylate); Unitika; 4. Synthetic mica; Topy Industries; PDM-9WA ; Relative permittivity =
6.2, dielectric loss tangent = 0.0008 5. Plate-like titanium oxide; trade name: luxelene, manufactured by Sumitomo Chemical Co., Ltd., relative dielectric constant = 45, dielectric loss tangent = 0.0005

[0019]

[Table 1]

[0020]

[Table 2]

Continued on the front page (72) Inventor Shusuke Tsutsumi 463 Kagasuno, Kawauchi-cho, Tokushima City, Tokushima Prefecture Inside the Tokushima Research Institute (72) Inventor Tomohiro Tanaka 463 Kasuno, Kawauchi-cho, Tokushima City, Tokushima Prefecture Tokushima Laboratory F-term (reference) 4J002 CF161 CH071 CH091 CM041 CN011 CN031 CN051 DJ006 DJ036 DJ046 DJ056 FA016 GQ01

Claims (3)

[Claims] 1. A synthetic resin having a melting temperature of 300 ° C. or higher and a flaky inorganic filler having a relative dielectric constant of 8 or lower at 1 MHz and a dielectric loss tangent of 0.004 or lower are compounded. And a resin composition for a circuit board. 2. The resin for a circuit board according to claim 1, wherein the scale-like inorganic filler having a relative dielectric constant of 8 or less at 1 MHz and a dielectric loss tangent of 0.004 or less is synthetic mica. Composition. 3. The synthetic resin having a melting temperature of 300 ° C. or higher is one or more selected from the group consisting of polyallyl ether ketone, polyetherimide, thermoplastic polyimide, and liquid crystal polymer. The resin composition for a circuit board according to claim 1 or 2, wherein