JPH0825771B2 - Glass composition and circuit board - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a glass composition and a circuit board.

[0002]

2. Description of the Related Art In an advanced information age, information transmission tends to be faster and higher in frequency. In mobile radio such as car telephones and personal radios, satellite broadcasting, satellite communications, and new media such as CATV, downsizing of devices is being promoted, and accordingly, microwave circuit elements such as dielectric resonators are being promoted. However, miniaturization is strongly desired.

The size of the microwave circuit element is based on the wavelength of the electromagnetic wave used. The wavelength λ of the electromagnetic wave propagating through the dielectric having the relative permittivity ε _r is λ = λ ₀ / (ε _r ) ^0.5 when the propagation wavelength in vacuum is λ ₀ . Therefore, the device becomes smaller as the permittivity of the printed circuit board used increases. Further, when the dielectric constant of the substrate is large, electromagnetic energy is concentrated in the substrate, which is convenient because there is little leakage of electromagnetic waves.

As the above-mentioned printed circuit board, there is a board in which a resin is reinforced with a reinforcing material made of fibers of a glass composition (hereinafter, appropriately referred to as "glass reinforcing material"). This printed circuit board is superior in price and post-processing (cutting, punching, etc.) to a ceramic board made of alumina or the like.
As a method of increasing the dielectric constant of this printed circuit board,
Polyvinylidene fluoride (ε _r = 13) and cyano resin (ε
_r = 16 to 20), there is a method using a resin having a high relative dielectric constant. In this case, however, the dielectric loss is large, and there is a problem in the stability of dielectric characteristics in a high frequency range.
It cannot be said that it is a very appropriate measure because it lacks the suitability for (00 MHz or more).

In addition, high relative dielectric constant inorganic particles (for example, Ti
Although there is a measure for improving the dielectric constant using a resin in which O ₂ particles and BaTiO ₃ particles are dispersed, there is a problem that the dielectric constant becomes uneven on the substrate surface due to the uneven dispersion of the high dielectric constant inorganic particles. Also, the appearance of the particle-resin interface is not preferable in terms of long-term reliability, and thus cannot be said to be an appropriate countermeasure.

In addition to the above, there is a dielectric constant improving measure using a glass reinforcing material (for example, glass cloth) having a high relative dielectric constant. A usual glass cloth for reinforcing material is composed of fibers of a SiO ₂ —Al ₂ O ₃ —CaO glass composition called E glass. More specifically, this E glass is made of S
iO _2: 50-60 wt%, Al ₂ O _3: 13~16 wt%, B ₂ O _3: 5~9 wt%, MgO: 0~6 wt%, CaO: 15-25 wt%, Na ₂ O + K ₂ O: 0
１1% by weight and F: 0０〜1% by weight, the relative dielectric constant is about 6-7, and the relative dielectric constant is not so high.

As a glass composition having a high relative dielectric constant, Pb
There is a lead-based glass composition containing a large amount of O. For example,
PbO: 72% by weight, SiO 2 : 26% by weight, B 2 O
A lead-based glass composition having a composition of 3 : 1.5 wt% and K 2 O: 0.5 wt% has a relative dielectric constant of 13.0 . However, in the case of a lead-based glass composition, fiberization (diameter 7-9μ
There is a problem that m) is difficult. PbO when melting glass
Evaporation is severe and becomes inhomogeneous, resulting in frequent yarn breakage in the spinning process. Further, in the case of a lead-based glass composition, there is a problem that it is difficult to form a glass cloth which is extremely suitable for reinforcement. In the case of manufacturing glass cloth, there is a heat treatment step for removing the primary binder, but the lead-based glass composition has a low strain point and is easily deteriorated, so that it is difficult to sufficiently perform the treatment. The glass cloth, which is not sufficiently treated to remove the primary binder, causes deterioration of long-term reliability of the substrate. In addition, in the case of a lead-based glass composition, there is a problem that it is not easy to handle because lead is toxic, and there is a problem that the dielectric loss (tan δ) in a high frequency region of 100 MHz or more is large.

Further, glass used as a reinforcing material for a printed circuit board also needs to have chemical durability. This is because various chemical treatments are performed when forming a circuit on a printed circuit board, and it is necessary that the reinforcing material is not damaged by this treatment.

[0009]

In view of the above-mentioned circumstances, the present invention provides a glass composition having good fiberization suitability, excellent dielectric properties even in a high frequency range, and excellent chemical durability. A second problem is to provide a circuit board having excellent dielectric characteristics even in a high frequency range and having high long-term reliability.

[0010]

[Means for Solving the Problems]
Therefore, the inventors₂-BaO-TiO₂-ZrO
₂Attention was paid to the system glass composition. This glass composition is non-lead
System with good dielectric properties and chemical durability
This is because they are rich in acidity, alkali resistance, and water resistance. Only
The problem is that the devitrification temperature is high and fiberization is difficult
There is. When obtaining glass fiber, 200-800 small
In front of a platinum pot called a bushing with a hole in the bottom
The melt is pulled out from the small hole to obtain the fiber, but the devitrification
When the temperature is high, devitrification crystals form on the bottom of the bushing.
Melt outflow is hindered and yarn breakage occurs. Normal, bushing
Devitrification is controlled by controlling the bottom temperature and the fiber winding speed.
Although glass fiber is obtained while suppressing the temperature, the devitrification temperature
Liquid viscosity is 10^2.5Poise (316 poise)
If you exceed it, you cannot control it.

[0011] Therefore, the present inventors have continued to earnestly investigate for a method of imparting the fiberization aptitude while ensuring the required dielectric properties and chemical durability, and the above-mentioned SiO ₂ —BaO—TiO _{2 is} used.
It is effective to add an appropriate amount of NbO _5/2 to the _2- ZrO ₂ glass composition so that the devitrification temperature does not exceed the temperature at which the melt viscosity becomes 10 ^2.5 poise (316 poise). I was able to obtain the knowledge that there is.

However, it was difficult to impart sufficient fiber-forming suitability only by adding NbO _5/2 . This is because the difference between the devitrification temperature and the temperature at which the melt viscosity becomes 10 ^2.5 poise does not easily become sufficiently large. When the difference between the devitrification temperature and the melt viscosity is 10 ^2.5 Poise temperature is small, the temperature change in the bushing causes a partial decrease in the glass melt temperature, which causes crystallization due to devitrification and facilitates yarn breakage. Therefore, it is very difficult to control fiberization, and it cannot be said that the suitability for fiberization is sufficient.

Therefore, the inventors have conducted further studies, and have been able to obtain the finding that it is very effective to add an appropriate amount of AlO _3/2 in addition to the addition of NbO _5/2. . That is, SiO ₂ —BaO—TiO ₂
The --ZrO ₂ -based glass composition is suitable because SiO ₂ -based cristobalite crystals and BaO--TiO ₂ --ZrO ₂ -based crystals mainly precipitate due to devitrification within a composition range where necessary dielectric properties can be secured. Although the addition of a large amount of NbO _5/2 suppresses the precipitation of the latter BaO—TiO ₂ —ZrO ₂ system crystals, the devitrification temperature is lowered, but the former SiO ₂ system cristobalite crystals are completely suppressed. However, there was a limit to the degree of devitrification temperature reduction.
Therefore, by adding an appropriate amount of AlO _3/2 at the same time,
Precipitation of SiO ₂ -based cristobalite crystals is also sufficiently suppressed, the devitrification temperature is further lowered, and the melt viscosity is increased, so that the difference between the devitrification temperature and the 10 ^2.5 poise temperature can be made larger. I was able to find out.
The devitrification temperature cannot be lowered to 10 ^2.5 poise temperature or lower only by adding AlO _3/2 without NbO _5/2 .

Therefore, in order to solve the first problem,
The glass composition of the invention according to claim 1, a SiO ₂ 40
˜65 mol%, at least one of CaO, SrO and BaO 20 to 45 mol%, TiO ₂ and ZrO ₂
Of at least one of 5 to 25 mol%, NbO _5/2 of 0.5 to 15 mol% and AlO _3/2 of 0.5 to 15 mol%
The total amount of these oxides is 85 mol% or more, the relative dielectric constant (1 MHz, 25 ° C) is 9 or more , and devitrification is performed.
The temperature is lower than the temperature at which the melt viscosity is 10 ^2.5 poise,
The glass composition of the present invention according to claim 2 further comprises S
The content of iO ₂ is 46 to 60 mol%, the content of at least one of CaO, SrO and BaO is 25 to 40 mol%, the content of at least one of TiO ₂ and ZrO ₂ is 7 to 24 mol%, and NbO _{5 / 2} content is 1-10
The composition is such that the mol% and the content of AlO _3/2 are 1 to 10 mol%.

Then, in order to solve the second problem,
A circuit board according to a third aspect of the present invention has a structure in which a resin is reinforced with a reinforcing material made of fibers of the glass composition according to the first or second aspect. Hereinafter, the present invention will be described in detail. Since the glass composition of the present invention has the above compositional constitution, the relative dielectric constant (1
Devitrification temperature is 10 ^2.5 poise
It is possible to secure excellent properties such as good fiberization suitability, which is lower than the temperature at which the temperature difference is 85 ° C. or more .

The relative permittivity (1 MHz, 25 ° C.) has a high permittivity of 9 or more. Dielectric loss (1 MHz, 25 ° C.), ie, tan δ0.6
% Or less. Even in the high frequency region of 100 MHz or more, the relative dielectric constant and the dielectric loss are slightly changed, and the high frequency dielectric property is excellent. It has excellent scientific durability (acid resistance, alkali resistance, water resistance).

The devitrification temperature is much lower than the temperature at which the melt viscosity becomes 10 ^2.5 poise, and it has a very good fiberization suitability. The temperature difference between the devitrification temperature and the 10 ^2.5 Poise temperature is 8
It can reach over 5 ° C. The strain point is as high as about 600 ° C. The reason for limiting the composition range of the glass composition of the present invention as described above is as follows.

SiO ₂ : 40 to 65 mol% (more preferably 46 to 60 mol%) SiO ₂ is a component that forms the skeleton of glass, and 40
If it is less than mol%, the devitrification temperature will increase and the melt viscosity will decrease, making it difficult to ensure the necessary fibrillation aptitude, and the chemical durability will also be insufficient. If it exceeds 65 mol%, it is difficult to secure a relative permittivity of 9 or more, and the glass viscosity is high, so that it is difficult to melt and become fibrous.

At least one of CaO, SrO and BaO: 20 to 45 mol% (more preferably 25 to 40)
Mol%) CaO, SrO, and BaO act as a modifying ion of the glass structure, and facilitate the melting. Further, the combined use causes a decrease in devitrification temperature. CaO, SrO and B
aO has a function of increasing the relative dielectric constant. If it is less than 20 mol%, it is difficult to obtain a melt, the suitability for fiber formation is reduced, and it is difficult to secure a relative dielectric constant of 9 or more. If it exceeds 45 mol%, the devitrification temperature will rise and the viscosity of the melt will decrease, making it difficult to secure the required fiber suitability.

At least one of TiO ₂ and ZrO ₂ : 5 to 25 mol% (more preferably 7 to 24 mol%) TiO ₂ and ZrO ₂ have a function of increasing the relative dielectric constant and a function of increasing chemical durability. . The combined use of TiO ₂ and ZrO ₂ is desirable, and the amount of TiO ₂ is often larger than that of ZrO ₂ . If it is less than 5 mol%, it is difficult to secure a relative dielectric constant of 9 or more and necessary chemical durability. If it exceeds 25 mol%, the devitrification temperature will rise and the suitability for fiber formation will be lost.

NbO _5/2 : 0.5 to 15 mol% (more preferably 1 to 10 mol%) NbO _5/2 has a function of significantly lowering the devitrification temperature without lowering the relative dielectric constant. If it is less than 0.5 mol%, the necessary addition effect is not exhibited, and if it exceeds 15 mol%, conversely the devitrification temperature rises. AlO _3/2 : 0.5-15 mol% (more preferably 1-
10 mol%) AlO _3/2 is a component that forms the skeleton of glass, and brings about a decrease in devitrification temperature and an increase in melt viscosity. If it is less than 0.5 mol%, the necessary addition effect is not exhibited, and if it exceeds 15 mol%, the relative dielectric constant is lowered, and the glass viscosity is excessively increased, which makes it difficult to melt and fiberize.

The total amount of the above oxides is 85 mol% or less.
If it is full, it is difficult or difficult to secure a relative permittivity of 9 or more.
It becomes difficult to secure proper fiberization suitability. In addition, the
The lath composition has a Li content of 15 mol% or less.₂O, N
a ₂O, K₂O, ZnO, MnO₂, TaO_5/2,BO
_3/2,LaO_3/2, CeO ₂At least oxides such as
It may be included.

Various compounds such as oxides (including complex oxides), carbonates, sulfates, chlorides, and fluorides can be used as raw materials for producing the above glass composition. All you have to do is In the case of the circuit board of the present invention, the resin is reinforced with the reinforcing material made of the fiber of the above glass composition, and a printed circuit is formed. The glass fiber reinforcement improves the mechanical strength and dimensional stability of the printed circuit board.

Examples of the form of the glass fiber reinforcing material include a cloth form, a mat form and a simple filament form. In the case of cloth or mat, the fiber diameter is usually 0.
Those having a thickness of about 5 to 20 μm and a thickness of about 15 μm to 1.5 mm are used. In the case of a filament, the fiber diameter is usually 2 to 5
Those having a length of 0 μm and a length of 20 to 300 μm are used.

The resin to be composited with the reinforcing material is not particularly limited, but for use in a high frequency range, a resin having a low high frequency loss (low tan δ) is preferable, and examples thereof include PPO (polyphenylene oxide) resin and fluororesin (for example, Teflon: a polyfluorinated ethylene resin such as the product name of DuPont), polycarbonate, polyethylene, polyethylene terephthalate, polypropylene, polystyrene and the like. The relative permittivity ε _r of these resins is usually about 2.0 to 3.2. A resin having a higher relative dielectric constant (for example, an epoxy resin, a polyester resin, polyvinylidene fluoride, a phenol resin, etc.) is preferable in terms of the relative dielectric constant, but has a large dielectric loss and is not particularly suitable for high frequencies.

The printed circuit board usually has a thickness of 0.
The ratio (volume ratio) of the resin and the reinforcing material is usually 30 to 95% by volume of the resin and 5 to 5% of the reinforcing material.
70% by volume. When manufacturing a printed circuit board, for example, a glass cloth is impregnated with a resin varnish prepared in advance and dried, and then a plurality of the obtained resin impregnated cloths are laminated (if necessary) on a metal. The foil is placed on the surface and heated and pressed by a mold. Then, as shown in FIG.
Are combined to complete the printed circuit board 4 having the metal foil 3 on the surface.

[0027]

The glass composition of the present invention is made of SiO₂40 to
65 mol%, at least CaO, SrO and BaO
20 to 45 mol% of one, TiO₂And ZrO₂of
5-25 mol% of at least one, NbO_5/20.
5-15 mol%, AlO _3/20.5 to 15 mol% it
The total amount of these oxides is 85 mol% or more.
Composition.

Therefore, the glass composition and the circuit board using the reinforcing material composed of the fibers of the glass composition have the following characteristics. First, the glass composition and the reinforcing material have a high relative dielectric constant of 9 or more (1 MHz, 25 ° C.) and a dielectric loss (1 MHz, 25 ° C.), that is, tan δ.
It has a low loss of 0.6% or less and a small change in the relative permittivity and the dielectric loss even in a high frequency range of 100 MHz, and has excellent high frequency dielectric characteristics. Further, since it is rich in chemical durability (acid resistance, alkali resistance, and water resistance) (much better than E glass), there is no problem of damage during chemical treatment during processing. Further, there is no problem such as toxicity in the case of a lead-based glass containing a large amount of PbO.

With respect to the glass composition, the devitrification temperature is much lower than the temperature at which the melt viscosity becomes 10 ^2.5 poise,
It is highly suitable as a reinforcing material because it has excellent suitability for fiberization and can be easily used as a glass fiber for reinforcing material. Moreover, the strain point is as high as about 600 ° C, and the primary binder removal treatment at the time of crossing can be performed appropriately. Can be any suitable glass cloth.

Regarding the circuit board according to the present invention,
The structure is such that the reinforcing material enhances the dielectric property, and the dielectric property is not enhanced by the high relative dielectric constant inorganic particles, so that the long-term reliability is also good.

[0031]

EXAMPLES Examples and comparative examples will be described below. "Examples and Comparative Examples of Glass Compositions" -Examples 1 to 25 and Comparative Examples 1 to 4 4-Glass composition raw materials were prepared so as to have the compositions shown in Tables 1 to 3, put in a platinum crucible and heated. (4 hours, 1500
° C) and melted. It should be noted that, as the raw material, the SiO ₂ S
iO ₂ , carbonate for CaO, SrO and BaO,
Anatase type TiO ₂ to TiO _2, the ZrO ₂ Z
rO ₂ and NbO _5/2 with NbO _5/2 primary reagent
The lO _3/2 was used as the primary reagent of AlO _3/2.

Then, the melt was cast onto a carbon plate, shaped into a plate, and annealed to obtain a plate glass. The following data were obtained for the plate glasses of each of the examples and comparative examples. —Relative Dielectric Constant and Dielectric Loss— First, the obtained plate-shaped glass was partially cut and polished to prepare a sample for dielectric property evaluation. Then, gold electrodes were formed on both surfaces of this sample by vapor deposition, and the relative permittivity and the dielectric loss (dielectric loss tangent) were measured by an impedance analyzer. The measurement frequency is 1 MHz and 1 GHz, and the temperature is 25 ° C.

[0033] -10 ^2.5 poise temperature - were measured measured 10 ^2.5 poise temperature the viscosity of the melt is dissolved a portion of sheet glass by a platinum ball pulling method. -Devitrification temperature-A part of the sheet glass is converted into a powder of 297 to 500 µm, placed in a platinum boat, kept in an electric furnace having a temperature gradient for 16 hours, then cooled in air, and a devitrification appearance position is determined under a microscope. Was measured.

-Fiberization Suitability-The rest of the plate glass is crushed and put in a platinum bushing, and the platinum bushing is directly energized to melt the glass, and the bushing temperature is set to 10 ^2.5 poise temperature. It was drawn out from the (nozzle) and wound to obtain glass fiber.

The above data are shown in Tables 1-3. In addition, in the said Example, although it made into plate glass and was re-melted and obtained glass fiber, you may make it obtain glass fiber directly from the first melt. Glass fibers can likewise be obtained.
For mass production, it is expedient to obtain the glass fibers directly from the initial melt.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

In the case of the example, the difference between the devitrification temperature and the 10 ^2.5 poise temperature was large as compared with the comparative examples 1 and 2, and there was sufficient aptitude for fiber formation, so that the fiber formation was easy. In the case of Comparative Examples 1 and 2 as well, although it is possible to somehow make fibers,
The work was not easy because the difference between the devitrification temperature and the 10 ^2.5 poise temperature was small, and strict temperature control was necessary so that devitrification did not occur during the work. Comparative Examples 3 and 4 are NbO _5/2.
Since the devitrification temperature was higher than 10 ^2.5 Poise temperature, it could not be formed into fibers.

The dielectric properties of the examples are good including the high frequency range. "Examples and Comparative Examples of Printed Circuit Boards" -Examples A to E and Comparative Examples A and B-Using the fibers obtained from the glass composition of Example 2, a glass cloth was obtained by a conventional method. This glass cloth is a plain woven glass cloth, having a thickness of 100 μm and a fiber diameter of 7 μm.
m, weave density: 60 lengths and 58 widths per 25 mm.

For comparison, a lead-based glass having the following composition and a glass cloth using E glass were also manufactured. "Lead glass" compositions PbO: 41.2 mol%, SiO _2: 55.3 mol%, B ₂ O _3: 2.8 mol%, K ₂ O: 0.7 mol% relative permittivity 1 MHz: 13.0 , 1 GHz: 12.9 dielectric loss 1MHz: 0.09%, 1GHz: 0.54 % "E-glass" compositions SiO _2: 57.9 mol%, Al ₂ O _3: 8.7
Mol%, B ₂ O _3: 7.3 mol%, CaO: 24.2 mol%, MgO: 1.6 mol%, K ₂ O: 0.3 mol% relative permittivity 1MHz: 6.5,1GHz: 6.5 Dielectric Loss 1 MHz: 0.15%, 1 GHz: 0.28% On the other hand, 150 parts by volume of tricrene was added to 100 parts by volume of PPO resin and stirred to prepare a resin varnish in which the PPO resin was completely dissolved. .

Then, the resin varnish was impregnated with glass cloth and then dried. The impregnation amount was adjusted so that the volume ratio between the PPO resin and the glass cloth was as shown in Tables 4 and 5. Five varnish-impregnated glass cloths thus obtained were stacked, copper foil (thickness: 17 μm) was placed on the top and bottom, and the temperature was adjusted to 2
Molding was performed at 50 ° C. under a pressure of 33 kg / cm ² for 10 minutes to obtain a double-sided copper foil-clad printed circuit board.

The relative permittivity and the dielectric loss of the substrates of Examples and Comparative Examples were measured. The measurement results are shown in Tables 4 and 5.

[0044]

[Table 4]

[0045]

[Table 5]

As can be seen from Tables 4 and 5, the printed circuit board of Example A has a smaller dielectric loss at 1 GHz than the comparative example A using lead glass, and the comparative example using E glass. It can be clearly seen that it has a higher relative permittivity than the B substrate and is suitable as a circuit substrate for a high frequency range.

[0047]

As described above, the glass composition of the present invention contains 40 to 65 mol% of SiO ₂ , CaO and Sr.
20 to 45 mol% of at least one of O and BaO and 5 to at least one of TiO ₂ and ZrO _2.
25 mol%, NbO _5/2 0.5 to 15 mol%, AlO
_3/2 is contained in an amount of 0.5 to 15 mol%, and the total amount of these oxides is 85 mol% or more, the high relative dielectric constant (9 or more), and the devitrification temperature is 10 ^2.5 poise. When
The temperature is lower than the temperature, the temperature difference is 85 ° C or more, good fiberization suitability is ensured, and it also has excellent high frequency dielectric properties, and has excellent chemical durability as a reinforcing material for circuit boards. It is suitable.

Since the circuit board of the present invention has a dielectric material enhanced by a reinforcing material composed of fibers of the glass composition having the above composition, it is a useful board having excellent high frequency dielectric characteristics and high long-term reliability. ing.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration example of a printed circuit board according to a third aspect of the invention.

[Explanation of symbols]

 1 Glass cloth (reinforcing material) 2 Resin 3 Metal foil 4 Printed circuit board

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Naka, 2-7-1, Harashirashi, Otsu-shi, Shiga Nippon Electric Glass Co., Ltd. (72) Inventor Shigeru Yamamoto 2-7-1 Harusan, Otsu, Shiga Japan Electric Glass Co., Ltd. (72) Inventor Tadashi Kokubo 2-chome, Umegaoka, Nagaokakyo-shi, Kyoto (56) References JP-A-3-297009 (JP, A) JP-A-4-106806 (JP, A)

Claims (3)

[Claims] 1. SiO ₂ of 40 to 65 mol%, CaO,
20 to 45 mol% of at least one of SrO and BaO and 5 of at least one of TiO ₂ and ZrO _2.
-25 mol%, NbO _5/2 0.5-15 mol%, Al
O _3/2 is contained in an amount of 0.5 to 15 mol%, the total amount of these oxides is 85 mol% or more, and the relative dielectric constant (1M
Hz, 25 ° C.) with 9 or more, the devitrification temperature melt viscosity 10 ^2.5 po
A glass composition having a fiberizing aptitude that is lower than the temperature at which it becomes azu and the temperature difference is 85 ° C. or more . _2. The content of SiO ₂ is 46 to 60 mol%,
The content of at least one of CaO, SrO and BaO is 25 to 40 mol%, the content of at least one of TiO ₂ and ZrO ₂ is 7 to 24 mol%, and the content of NbO _5/2 is 1 to 10 mol%, The content of AlO _3/2 is 1 to 1
The glass composition according to claim 1, which is 0 mol%. 3. A circuit board obtained by reinforcing a resin with a reinforcing material composed of the fiber of the glass composition according to claim 1.