JPH10120437A - Low dielectric constant glass fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass fiber, having a low dielectric constant and a low dielectric dissipation factor, excellent in water resistance, having a low spinning temperature and excellent in productivity and operating efficiency by including a specific glass composition therein. SOLUTION: This glass fiber is obtained by providing a glass composition of 50-56wt.% SiO2 , 10-18wt.% Al2 O3 , 18-25wt.% B2 O3 , >10 and <=17wt.% CaO, 0-4wt.% MgO, 0-1.0wt.% total amount of Li2 O, Na2 O and K2 O and 0-2wt.% F2 , preferably a glass composition of 52-55wt.% SiO2 , 12-15wt.% Al2 O3 , 20-24wt.% B2 O3 , 11-15wt.% CaO, 0-3wt.% MgO, 0-0.3wt.% Li2 O, 0-0.3wt.% Na2 O, 0-0.4wt.% K2 O and 0-1wt.% F2 . As a result, the glass fiber having <=5.5 dielectric constant, <=10×10<-4> dielectric dissipation factor, <=1,300 deg.C spinning temperature and <=1% percentage loss of weight is obtained.

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 glass fiber, and more particularly, to a low dielectric constant glass fiber having a low dielectric loss tangent suitable for reinforcing a high-density printed wiring board requiring a low dielectric loss tangent. About.

[0002]

2. Description of the Related Art In recent years, in the era of the advanced information society, communication devices such as satellite broadcasting and mobile radio tend to be digitized and processed at high speed. These include reinforcements, resins,
A printed wiring board composed of a composite material composed of a material such as a modifier and a filler is used, and glass fiber is widely used as a reinforcing material thereof. Conventionally, E glass is known as this kind of commercially produced glass fiber.

Generally, when an alternating current is applied to glass, the glass absorbs energy with respect to the alternating current and absorbs heat as heat. The absorbed dielectric loss energy is proportional to the dielectric constant and the dielectric loss tangent determined by the composition and structure of the glass, and is expressed by the following equation.

W = kfv2 × εtanδ where W is the dielectric loss energy, k is a constant, f is the frequency, v2 is the potential gradient, ε is the dielectric constant, and tanδ is the dielectric loss tangent.

From this equation, it can be seen that as the dielectric constant and the dielectric loss tangent increase, and as the frequency increases, the dielectric loss increases.

In the case of E glass, for example, the dielectric constant at a frequency of 1 MHz at room temperature is 6.7 and the dielectric loss tangent is 12 ×.
10-4, which is insufficient for a printed wiring board using E glass to meet the demands for higher density and faster signal processing. Therefore, a glass having a dielectric constant and a dielectric loss tangent lower than that of E glass is desired. As one such glass, a glass called D glass has been developed. D glass is, for example, 75.3% of SiO2,
B2O3 20.5%, CaO 0.6%, MgO0.4
%, Li2 O 0.6%, Na2 O 1.1%, K2 O
It is a glass having a composition of 1.5%. For example, the dielectric constant at a frequency of 1 MHz at room temperature is 4.3 and the dielectric loss tangent is 10.times.10@-4.

[0007]

However, D glass is
Because the meltability is poor and striae and bubbles are likely to occur, in the spinning process, glass fiber is often cut and productivity and workability are poor.
Further, since the spinning temperature is very high, there is a disadvantage that the life of the furnace is short. Further, D glass has poor water resistance and poor adhesion to resin, so that it is liable to peel off from resin in a printed wiring board, and high reliability cannot be obtained when the printed wiring board is used. is there.

Japanese Patent Application Laid-Open No. 6-219780 discloses that Si
O2 50.0 to 65.0%, Al2 O3 10.0 to 1
8.0%, B2O3 11.0-25.0%, MgO
6.0-14.0%, CaO 1.0-10.0%, Z
nO 0 to 10, MgO + CaO + ZnO 1
A low dielectric constant glass of 0.5-15% is disclosed. This glass has a content of MgO of 6% or more, and CaO + M
By increasing the ratio of gO + ZnO to 10.5% or more, the spinning temperature is lowered to improve productivity. However, M is a component that has a strong phase separation property and a high dielectric loss tangent.
Since gO is 6% or more, sufficient water resistance cannot be obtained, and the dielectric loss tangent thereof is relatively high.

Japanese Patent Application Laid-Open No. 7-10598 discloses S
iO2 50.0 to 65.0%, Al2 O3 10.0 to
18%, B2O3 11.0-25.0%, CaO 0-0
10.0%, MgO 0 to 10.0%, MgO + CaO
1.0-15.0%, ZnO 0-10.0%, SrO
A glass having a composition of 0 to 10.0% and BaO of 1 to 10.0% is disclosed. However, since this glass also contains BaO, which is a component that increases the dielectric constant, as an essential component, it is difficult to obtain a sufficiently low dielectric constant. In order to obtain a low dielectric constant, the ratio of BaO must be reduced. I cannot help but
In that case, there is a problem that the viscosity of the glass increases and the spinning workability deteriorates. In addition, BaO also has a problem that the life of the melting furnace is short because the erosion of the furnace material of the glass melting furnace is large.

The present invention has been made in view of the above circumstances, and provides a glass fiber having characteristics of low dielectric constant and dielectric loss tangent, excellent productivity, workability, and excellent water resistance. It is intended to provide.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted various studies to achieve the above object, and as a result, in the glass fiber composition, in particular, the content of SiO2 was reduced to 56% or less,
By setting O to 10% or more, the spinning temperature of the glass is lowered, and by further setting B2 O3 to 18% or more, the dielectric constant is 5.5 or less and the dielectric loss tangent is 10.times.10@-4.
Was obtained.

Accordingly, the present invention relates to a method for preparing SiO2
50 to 56%, Al2 O3 10 to 18%, B2 O3 1
8 to 25%, CaO over 10% and up to 17%, Mg
O 0-4%, Li2 O + Na2 O + K2 O 0-1.0
% And a glass composition of F2 0 to 2%.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The reasons for limiting the composition of glass fibers in the present invention are as follows.

[0014] SiO2 is a component that forms a glass skeleton together with Al2O3 and B2O3. If the content of SiO2 is less than 50%, the dielectric constant becomes too large, and the water resistance and acid resistance are reduced. This causes deterioration of the printed wiring board using the reinforcing material.
If it exceeds 56%, the viscosity may be too high, and fiberization may be difficult during spinning. Therefore, SiO2 is 50 ~
It is limited to 56%, preferably 52 to 55%.

If the content of Al 2 O 3 is less than 10%, the phase separation becomes strong and the water resistance becomes poor. If it exceeds 18%,
The liquidus temperature rises and spinnability deteriorates. Therefore, Al2 O3
Is limited to 10 to 18%, preferably 12 to 15%.

B 2 O 3 is used as a flux to lower the viscosity and facilitate melting, but if it is less than 18%, the dielectric constant and the dielectric loss tangent become too large. If it exceeds 25%, the amount of volatilization at the time of melting increases, so that a homogeneous glass cannot be obtained and the water resistance becomes too poor. Therefore B2
O3 is limited to 18 to 25%, preferably 20 to 24%.
%.

CaO is a component that acts as a flux together with MgO. However, it has a weaker phase separation property than MgO, and when CaO elutes with water as Ca (OH) 2, B 2 O 3 Of H3BO3, it is possible to prevent a decrease in water resistance. If it is less than 10%, the viscosity increases and the meltability deteriorates, and the water resistance also deteriorates. If it exceeds 17%, the dielectric constant becomes too large. Therefore, CaO is limited to more than 10% and 17% or less,
Preferably it is 11 to 15%.

MgO is a component used as a flux to lower the viscosity and facilitate melting.
When it exceeds, the dielectric loss tangent becomes large and the phase separation becomes strong. Therefore, MgO is limited to 0-4%, preferably 0-3%.

Li2 O, Na2 O, and K2 O are effective components as fluxing agents. However, if the total exceeds 1.0%, the dielectric loss tangent becomes too high and the water resistance deteriorates. Therefore L
i2O + Na2O + K2O is limited to 0 to 1.0%,
Preferably it is 0 to 0.6%.

If the content of Li 2 O and Na 2 O exceeds 0.3%, and if the content of K 2 O exceeds 0.4%, the dielectric loss tangent may become too high. Therefore, preferably Li2O,
Na2O is 0 to 0.3%, and K2O is 0 to 0.4%. More preferably, Li2O is 0-0.2%, Na2O
Is 0.1 to 0.2% and K2O is 0 to 0.2%.

F2 is a component as a flux that lowers the viscosity of the glass and lowers the dielectric constant and especially the dielectric loss tangent.
Heat resistance deteriorates. Therefore, F2 is limited to 0-2%, preferably 0-1%.

Incidentally, in the glass composition of the present invention, other than the above components, Zn is added to such an extent that the glass properties are not impaired.
O, SrO, TiO2, Cr2 O3, As2 O3, Sb2
Components such as O3, P2O5, ZrO2, Cl2, SO3 and MoO2 can be contained up to 2%.

Preferred physical properties of the low dielectric constant glass fiber of the present invention include a dielectric constant of 5.5 or less, a dielectric loss tangent of 10 × 10 −4 or less, a spinning temperature of 1300 ° C. or less, and 1% by weight.
The weight loss rate is as follows.

The glass fiber of the present invention is preferably 52 to 55% by weight of SiO 2 and 12 to 15% of Al 2 O 3 by weight.
%, B2O3 20-24%, CaO 11-15%, M
gO 0-3%, Li2 O 0-0.3%, Na2 O0
It has a glass composition of 0.3%, K2 O 0-0.4% and F2 0-1%.

The glass fiber of the present invention is produced according to a known glass production technique such as E glass, C glass, D glass and the like.

The glass fiber of the present invention has a low dielectric constant and a low dielectric loss tangent, and is used as a glass fiber for a printed wiring board, particularly for a printed wiring board corresponding to high-density wiring and high-speed signal processing. Excellent for strengthening. Further, since the spinning temperature is low and the water resistance is excellent, a low-dielectric-constant glass fiber having excellent quality can be stably obtained.

The low dielectric glass fiber of the present invention can be used to obtain various fiber reinforced resin base materials such as glass fiber woven fabric, nonwoven fabric, knit, glass powder, glass chopped strand and the like.

For example, in order to obtain a glass powder, the glass bulk may be pulverized, or may be pulverized after forming into glass fibers. In order to pulverize the glass bulk or the fiberized glass fiber, it can be obtained by using a known apparatus alone or in combination such as a ball mill, a fred mill, a hammer mill, an orient mill, and an impeller mill.

Various substrates comprising the glass fiber of the present invention,
For example, woven, non-woven, knitted, chopped strand,
Roving, glass powder, mats and the like, and a composite material (eg, sheet molding compound, bulk molding compound, prepreg) composed of a mixture of a base material thereof, various thermosetting resins, and a thermoplastic resin have a low dielectric constant, Taking advantage of the characteristic of low dielectric loss tangent, it can be used as a base material for reinforcing various resins in, for example, peripheral members of communication devices.

[0030]

EXAMPLES The low dielectric constant glass fiber of the present invention will be described in detail based on examples.

Examples 1 to 8 Table 1 shows the low dielectric constant glass fibers of the present invention. First, a batch prepared so as to have a glass composition of each sample shown in Table 1 was put in a platinum crucible and melted in an electric furnace at 1500 to 1550 ° C. for 8 hours while stirring. Next, the molten glass was poured onto a carbon plate to prepare a glass cullet. After putting this glass cullet into a glass fiber manufacturing furnace, it is 1200 to 13
When the mixture was melted at 00 ° C. and spun, a large amount of boric acid generated when D glass was spun was not observed, and the spinning was performed without any inconvenience.

On the other hand, a glass cullet was melted into a plate, cooled slowly, and a double-sided optically polished sample having a diameter of 45 mm and a thickness of 2 mm was prepared. The dielectric constant and the dielectric loss tangent at a frequency of 1 MHz at room temperature were measured using an impedance analyzer. Was measured. As the spinning temperature, the glass cullet was re-melted with a platinum crucible, and the temperature (° C.) when the viscosity η (poise) was 103 was measured while measuring the viscosity of the melt with a Vismestron viscometer.

Further, as for the water resistance, distilled water at a temperature of 13
The weight loss rate of the glass component after immersion at 3 ° C. for 24 hours was measured.

Comparative Example Table 1 shows examples of E glass and D glass as comparative examples.

[0035]

[Table 1]

[Results] As shown in Table 1, the glass fibers of Examples have a dielectric constant of 5.5 or less, which is lower than that of E glass, and a dielectric loss tangent of 10 × 10 -4 or less. E
It is lower than glass and shows a value equal to or lower than that of D glass.

The spinning temperature of the glass fiber of the example is 10 3 when the viscosity μ (poise), which is a standard for spinning, is 10 3.
The temperature is 300 ° C. or lower, which is lower than that of D glass.

Further, the weight reduction rate of the glass component is almost equal to that of the E glass, and is much lower than 3.7% of the D glass.

[0039]

The glass fiber of the present invention has a low dielectric constant and a low dielectric loss tangent, and is used as a glass fiber for a printed wiring board, especially for a printed wiring corresponding to high-density wiring and high-speed signal processing. Excellent for strengthening substrates. Further, since the spinning temperature is low and the water resistance is excellent, a low-dielectric-constant glass fiber having excellent quality can be stably obtained.

Claims (2)

[Claims] 1. The composition according to claim 1, wherein the content of SiO2 is from 50 to 56% by weight,
l2 O3 10-18%, B2 O3 18-25%, Ca
O 10% to 17% or less, MgO 0 to 4%, Li
2 O + Na2 O + K2 O 0-1.0%, F2 0-2%
Low-permittivity glass fiber, characterized by having the following glass composition: 2. The composition according to claim 1, wherein the content of SiO2 is from 52 to 55% by weight.
l2 O3 12-15%, B2 O3 20-24%, Ca
O 11-15%, MgO 0-3%, Li2O 0
0.3%, Na2 O 0-0.3%, K2 O 0-0.4
The low dielectric constant glass fiber according to claim 1, which has a glass composition of 0% to 1% of F2.