JP2002137937A - Glass fiber having low dielectric constant and low dielectric tangent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass fiber for print circuit board having low dielectric constant and low dielectric tangent, and excellent in meltability and spinnability of glass. SOLUTION: This glass fiber having low dielectric constant and low dielectric tangent comprises in mol% 47.0 to 67.0 of SiO2, 6.0 to 15.0 of Al2O3, 10.0 to 30.0 of B2O3, 6.0 to 11.0 of MgO, and 5.0 to 9.0 of CaO whereas comprising substantially no alkali nor fluorine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low dielectric constant and low dielectric loss tangent glass fiber used as a resin reinforcing material for a printed wiring board of a circuit component for electronic equipment utilizing high frequency.

[0002]

2. Description of the Related Art A printed wiring board is a composite material comprising a resin, glass fiber, a modifier and the like. Among them, glass fiber is used as a resin reinforcing material, and E glass is conventionally used as glass fiber for a printed wiring board.

In recent years, information communication devices such as computers and mobile phones have been reduced in size and performance, and radio waves used for high-speed processing of signals have been increasing in frequency.

[0004] Along with such movements, demands have been made for a printed wiring board used as a circuit component of information communication equipment, for example, to increase the density and to improve the high frequency characteristics.

[0005] High-speed signal processing sometimes reduces the signal propagation delay, but the signal propagation delay time is correlated with the dielectric constant of the printed circuit board, as shown in the following equation. It is known that the signal propagation delay decreases as the value of the dielectric constant of the substrate decreases.

[0006]

(Equation 1)

Td is the signal propagation delay time per unit length of the conductor, k is a constant, and ε is the permittivity of the printed circuit board.

When a high frequency is used for high-speed processing of a signal, heat loss increases in a normal printed wiring board, which causes heat generation and causes a problem of thermal deterioration of the printed wiring board. . Further, in view of such heat loss, high output is required for the oscillation of the electric signal. This heat loss is proportional to the product of the dielectric constant and the dielectric loss tangent of the printed wiring board, as shown by the following equation, and the heat loss increases as this value increases.

[0009]

(Equation 2)

W is a loss, k is a constant, f is a frequency, v ² is a potential gradient, ε is a permittivity of a printed wiring board, and tan δ is a dielectric loss tangent of the printed wiring board.

From the above equations, it can be seen that the larger the dielectric constant and the dielectric loss tangent of the printed wiring board, the greater the heat loss.

In order to suppress signal propagation delay and heat loss, a printed circuit board has a dielectric constant (ε) and a dielectric loss tangent (ta).
A glass fiber made of D glass in which nδ) is smaller than E glass may be used.

D glass is, for example, SiO _{2 in} mol%.
75.3%, Al ₂ O ₃ 0.2%, B ₂ O ₃ 20.0
%, MgO 0.4%, CaO 0.6%, Li ₂ O
It is a glass having a composition of 0.9%, Na ₂ O 1.1%, and K ₂ O 1.5%, and has a dielectric constant (ε) of 4.3 and a dielectric loss tangent (tan δ) of 10 × 10 ^−4. It is. Incidentally, E glass has a dielectric constant (ε) of 6.6 and a dielectric loss tangent (tan δ) of 15 × 10 ⁻⁴ .

However, D glass has the following problems. That is, the glass fiber made of D glass has poor water resistance and is easily peeled off from the resin, and a printed wiring board using D glass as a resin reinforcing material has a high hardness when drilling to form a via. The drilling rate is high, and the drill is severely worn, resulting in poor machining efficiency. Further, D glass has a problem that it is difficult to melt and spin the glass because the content of silica is high and the high temperature viscosity is high.

The present invention has been made in view of the above-mentioned problems, and has as its object to reduce both the dielectric constant and the dielectric loss tangent as compared with E glass, and
Excellent water resistance and drilling workability compared to D-glass,
Another object of the present invention is to provide a glass fiber for a printed wiring board, which is easy to melt and spin glass.

As a result of repeated experiments to achieve the above object, the present inventors have found that, in particular, SiO ₂ —Al ₂ O ₃ —B ₂ O ₃
-RO glass has been found to satisfy the desired properties,
The present invention has been made.

That is, the low dielectric constant and low dielectric loss tangent glass fiber of the present invention has a molar percentage of SiO _{2 of} 47.0 to 67.0.
_{%, Al 2 O 3 6.0~15.0%} , B 2 O 3 10.0
~ 30.0%, MgO 6.0 ~ 11.0%, CaO
It has a composition of 5.0 to 9.0%, contains substantially no alkali and fluorine, has a dielectric constant of 5.5 or less, a dielectric loss tangent of 13 × 10 ⁻⁴ or less, and a spinning temperature of 1390 ° C. Hereinafter, the difference between the spinning temperature and the liquidus temperature is 80 ° C. or more.

The low dielectric constant and low dielectric loss tangent glass fiber of the present invention is composed of 50.0 to 65.0% of SiO _{2 by} mole%,
l ₂ O ₃ 7.0 to 13.0%, B ₂ O ₃ 11.0 to ₂
8.0%, MgO 6.5 to 10.5%, CaO 5.
A composition of 5 to 8.5%, containing substantially no alkali and fluorine, and having a dielectric constant of 5.0 or less, a dielectric loss tangent of 11 × 10 ^-4 or less, a spinning temperature of 1370 ° C. or less, The difference between the spinning temperature and the liquidus temperature is 100 ° C. or more.

[0019]

The respective components of the low dielectric constant and low dielectric loss tangent glass fibers according to the present invention are limited as described above for the following reasons.

SiO ₂ is a component that forms the skeleton of glass and has the effect of reducing the dielectric constant and dielectric loss tangent of the glass.
It is 7.0%, preferably 50.0 to 65.0%. If the content is less than 47.0%, the effect cannot be obtained.
If the content is more than 67.0%, the high-temperature viscosity of the glass increases, so that the melting property of the glass deteriorates, and the drill workability deteriorates when manufacturing a printed wiring board.

Al ₂ O ₃ is a component for improving the melting property and the devitrification property of the glass without deteriorating the electric characteristics, and its content is 6.0 to 15.0% by mol%, preferably 7.0 to 13.0%. If the content is less than 6.0%, such an improvement effect cannot be obtained, and if it exceeds 15.0%, the devitrification of the glass increases.

B ₂ O ₃ is a component that lowers the high-temperature viscosity of the glass, acts as a flux, and also has a function of reducing the dielectric constant and the dielectric loss tangent of the glass. 0.0 to 30.0%, preferably 11.0
~ 28.0%. If the content is less than 10.0%, these effects cannot be obtained. If the content is more than 30.0%, the amount of volatilization increases during melting and spinning of the glass, leading to deterioration in productivity, and Water resistance deteriorates.

MgO is a component having an effect of lowering the high-temperature viscosity of glass, and is also used as a flux. Its content is 6.0 to 11.0% by mol%, preferably 6.5 to 10%.
5%. If the content is less than 6.0%, a sufficient effect cannot be obtained, and if it exceeds 11.0%, the dielectric constant becomes large and the glass is apt to be devitrified, which is not preferable.

CaO is used as a flux together with MgO and is a component having an effect of lowering the high-temperature viscosity of glass, and its content is 5.0 to 9.0% by mol%, preferably 5.5 to 8%. 0.5%. If the content is less than 5.0%, a sufficient effect cannot be obtained, and if the content is more than 9.0%, the dielectric constant becomes large, which is not preferable.

In the present invention, if the glass contains an alkali, the dielectric loss tangent exceeds 20 × 10 ⁻⁴ , so that the alkali should not be substantially contained. However, it is unavoidable that alkalis of up to about 0.2% by mol% are mixed in due to impurities in the raw material.

Table 1 shows the dielectric loss tangent tan of alkali glass.
The effect on δ (× 10 ⁻⁴ ) is shown. Table 1 shows that the presence of 0.5% by mole of alkali significantly increases the dielectric loss tangent.

[0027]

[Table 1]

Fluorine is preferably not contained because it volatilizes during glass production and harms the surrounding environment.

In the present invention, BaO, Z, and the like other than the above-mentioned components are also added to such an extent that the desired glass properties are not impaired.
_{nO, SrO, TiO 2, Fe} 2 O 3, P 2 O 5, SO 3, A
Components such as s ₂ O ₃ and MoO ₂ can be combined up to 3 mol%.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The low dielectric constant and low dielectric loss tangent glass fiber of the present invention will be described below by way of examples.

Tables 2 and 3 show examples (samples No. 1 to No. 7) and comparative examples (samples No. 8 to No. 9) of the low dielectric constant and low dielectric loss tangent glass fibers of the present invention, respectively. Things. Sample No. of Comparative Example 8 is E glass, sample N
o. 9 is D glass.

[0032]

[Table 2]

[0033]

[Table 3]

The preparation method of each sample in the table is as follows.

First, 500 g of glass raw materials each prepared to have a predetermined composition were put into a platinum crucible and melted in an electric furnace at about 1580 ° C. for 4 hours. Next, the molten glass was poured onto a carbon plate and formed into a plate shape, and then gradually cooled to remove a strain, thereby preparing a sample.

The dielectric constant (ε), the dielectric loss tangent tan δ (× 10 ⁻⁴ ), the spinning temperature, the liquidus temperature, and the difference between the spinning temperature and the liquidus temperature (ΔT) of each of the above-prepared samples are described.
Are shown in the table.

As is clear from the table, the N
o. 1 to No. 7 each had a dielectric constant of 4.9.
Hereinafter, the dielectric loss tangent is as small as 10 × 10 ⁻⁴ or less. Moreover, the spinning temperature is 1365 ° C. or less, and the difference between the spinning temperature and the liquidus temperature is 115 ° C. or more, so that the spinnability is good.

In contrast to the above example, sample N which is a comparative example
o. No. 8, the spinning temperature is low, but both the dielectric constant and the dielectric loss tangent are large. In addition, the sample No. No. 9 has a high spinning temperature and is difficult in terms of glass meltability and spinnability.

The dielectric constant and the dielectric loss tangent in the table were determined by cutting each sample to a size of 50 mm × 50 mm × 3 mm, polishing both surfaces with a No. 1000 sandpaper, and then using an impedance analyzer at room temperature. Each value was measured at a frequency of 1 MHz.

The spinning temperature is such that each sample is put into an alumina crucible and re-melted, and the temperature of the melt is measured by a platinum ball pulling method, and is a temperature corresponding to a viscosity of 10 ³ poise.

The liquidus temperature was set at 300 to 500 μm for each sample.
Crushed into small pieces and placed in a container made of platinum.
After holding for 6 hours, the devitrification temperature point was measured.

[0042]

As described above, the low dielectric constant and low dielectric loss tangent glass fiber of the present invention has a dielectric constant of 5.5 or less and a dielectric loss tangent of 1 or less.
Since each is as small as 3 × 10 ⁻⁴ or less, it can be used as a resin reinforcing material for a printed wiring board which is required to cope with high-speed processing of signals, has good drill workability, and has a spinning temperature of 1390. C. or less, and the difference between the spinning temperature and the liquidus temperature is 80.degree. C. or more, so that the glass has excellent meltability and spinnability, and is suitable for mass production of glass fibers.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4G062 AA05 BB05 CC10 DA05 DA06 DB03 DB04 DC04 DD01 DE01 DF01 EA01 EB01 EC01 ED03 ED04 EE03 EF01 EG01 FA01 FA10 FB01 FC01 FD01 FE01 FF01 FG01 FH01 FJ01 GA01 GB01 GA01 HH01 HH03 HH05 HH07 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM15 MM28 NN26

Claims (2)

[Claims] 1. The composition according to claim 1, wherein the molar percentage of SiO _{2 is} 47.0 to 67.
0%, Al ₂ O ₃ 6.0 to 15.0%, B ₂ O ₃ 10.
0-30.0%, MgO 6.0-11.0%, CaO
It has a composition of 5.0 to 9.0%, contains substantially no alkali and fluorine, has a dielectric constant of 5.5 or less, a dielectric loss tangent of 13 × 10 ⁻⁴ or less, and a spinning temperature of 1390 ° C. or less. ,
A low dielectric constant and low dielectric loss tangent glass fiber, wherein a difference between a spinning temperature and a liquidus temperature is 80 ° C. or more. _{2. The} amount of SiO _{2 in the} range of 50.0 to 65.
_{0%, Al 2 O 3 7.0~13.0} %, B 2 O 3 11.
0-28.0%, MgO 6.5-10.5%, CaO
It has a composition of 5.5 to 8.5%, contains substantially no alkali and fluorine, has a dielectric constant of 5.0 or less, a dielectric loss tangent of 11 × 10 ^-4 or less, and a spinning temperature of 1370 ° C. or less. ,
The low dielectric constant and low dielectric loss tangent glass fiber according to claim 1, wherein the difference between the spinning temperature and the liquidus temperature is 100 ° C or more.