JPH03297009A - Compound dielectrics - Google Patents

Abstract

PURPOSE:To prevent a reinforcing material made of glass from interfering with maintaining a high dielectric constant by using non-lead glass having a dielectric constant 9 or higher as at least a part of glass of glass constituting the reinforcing material made of resin reinforcing glass. CONSTITUTION:This is compound dielectrics wherein resin is reinforced by a reinforcing material made of glass, while at least a part of the glass constituting the reinforcing material is non-lead glass of a dielectric constant 9 or higher. The reinforcing material made of glass may be cloth-like, mat-like or fiber-like, for example, which can normally be obtained by spinning melt solution of glass material to be glass fiber (fiber molded) and then processing it. The entire reinforcing material is preferably made of non-lead glass of a dielectric constant 9 or higher, while only a part may be the lead glass of a dielectric constant 9 or higher. Thus it is easy to maintain a high dielectric constant of compound dielectrics itself and the derivative is free from lead poisoning of non-lead glass and safe so that it is highly practical.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to composite dielectrics.

[Conventional technology]

As we enter the advanced information age, information transmission tends to become faster and more frequent. Mobile radios such as car telephones and personal radios, new media such as satellite broadcasting, satellite communications, and CATV are also at the stage of practical application.

On the other hand, in mobile radio and new media, devices are becoming more compact, and along with this, there is a strong demand for smaller microwave circuit elements such as dielectric resonators.

The size of a microwave circuit element is based on the wavelength of the electromagnetic waves used. The wavelength λ of an electromagnetic wave propagating in a dielectric material with relative permittivity εr is λ=λ, where λ is the propagation wavelength in vacuum.
, /εr0·5. Therefore, the larger the relative dielectric constant of the printed circuit board substrate used, the smaller the device becomes. Further, when the dielectric constant of the substrate is large, electromagnetic energy is concentrated within the substrate, which is advantageous in that leakage of electromagnetic waves is small.

As the substrate for the printed circuit board, there is a substrate using a composite dielectric material made of a resin (such as a PPO resin having excellent high frequency characteristics) reinforced with a reinforcing material made of glass (glass reinforcing material). This printed circuit board substrate is manufactured by A et al. It is attracting attention because it is superior to ceramic substrates in terms of price and post-processing (cutting, drilling, adhesion, etc.).

[Problem to be solved by the invention]

However, conventional substrates made of composite dielectrics made of resin reinforced with glass reinforcing materials cannot be said to have sufficient dielectric constant.

Since resin has a low dielectric constant, inorganic dielectric powder is usually used in combination to compensate for this, but even then, it is difficult to achieve a suitably large dielectric constant. Although increasing the content of inorganic dielectric powder increases the dielectric constant, there are disadvantages such as increased cost and increased interface trouble. The reason why the dielectric constant cannot be increased sufficiently even when an inorganic dielectric constant is used in combination is because the dielectric constant of the glass reinforcing material is not high. A glass reinforcing material with a low relative permittivity divides the high permittivity resin region in which inorganic dielectric powder is dispersed, creating a series-coupled state of capacitance internally, resulting in a high relative permittivity of the substrate. This prevents the The reason why the dielectric constant of the composite dielectric material for the substrate is set to an appropriate value (for example, 10 to several 10) is that if the dielectric constant is too large, processing for forming a circuit becomes difficult.

In view of the above circumstances, it is an object of the present invention to provide a composite dielectric material in which a reinforcing material made of glass does not interfere with ensuring a high relative dielectric constant.

(Means for Solving the Problems) In order to solve the above problems, in the composite dielectric of the present invention,
At least a part of the glass constituting the reinforcing material made of glass reinforcing the resin is made of lead-free glass having a dielectric constant of 9 or more. Furthermore, it is preferable that the relative dielectric constant of the lead-free glass is 12 or more.

The composite dielectric of the present invention will be explained in more detail below.

As the composite (matrix) resin in this invention, an appropriately selected resin is used as required, but in applications in the high frequency range, resins with low high frequency loss (low tan) are used.
δ) Resins are preferred, and include, for example, PPO (polyphenylene oxide) resins, fluororesins (for example, polyfluoroethylene resins commonly known as Teflon), polycarbonates, polyethylene, polyethylene terephthalate, polypropylene, polystyrene, and the like. The dielectric constant εr of these resins is usually about 2.0 to 3.2. For other applications, polyester, epoxy, or PV with a high dielectric constant may be used, although the loss is somewhat inferior.
A resin such as DF (polyvinylidene fluoride) may also be used.

Reinforcing materials made of glass include cross-shaped, matt-shaped,
Fiber-like fibers are exemplified, and these are usually obtained by spinning a melt of a glass raw material to form glass fibers (fiber molding) and then processing the fibers. In the case of cloth or mat, the thickness is usually 1.5. A glass fiber with a diameter of about n-1.5fi and a glass fiber diameter of about 0.5 to 30p is used. In the case of fibers, those with a length of about 20 to 300 nm and a glass fiber diameter of about 2 to 50 nm are usually used. The entire reinforcing material is preferably made of lead-free glass with a dielectric constant of 9 or more, but only a portion may be made of lead-free glass with a dielectric constant of 9 or more. For example, it may be a cloth in which only the warp threads are fibers of non-lead glass having a dielectric constant of 9 or more, and the weft threads are fibers of glass other than lead-free glass having a dielectric constant of 9 or more.

Lead-free glass with a dielectric constant of 9 or more used in glass reinforcement materials includes 15 mol of silicon oxide (Stow).
% or more and 60 mol% or less, magnesium oxide (MgO)
, calcium oxide (Cab), strontium oxide (S
r O) and barium oxide (B a O) (hereinafter referred to as "Group A oxide" as appropriate)
0Il101% or more and 40+woffi% or less, titanium oxide (T i O-), zirconium oxide (Z
rOs) and at least one oxide of tin oxide (SnO3) (hereinafter appropriately referred to as "Group B oxide")
O+*o 1% or more 55m.

These oxides (silicon oxide, A
The total amount of group oxides and group B oxides is 85 mol%.
The above can be mentioned.

When silicon oxide exceeds 60 mol %, it becomes difficult to ensure a dielectric constant of 9 or more.

Silicon oxide is 15a+oj! %, if the amount of group A oxide exceeds 40+o1%, or if the amount of group B oxide exceeds 55 mol%, fiber formability will decrease.

Furthermore, in the lead-free glass having the composition shown in claim 2,
As in claim 3, the content of silicon oxide is 35s+oj
! % or more 50a+oj! % or less, the content of at least one oxide (group A oxide) among magnesium oxide, calcium oxide, strontium oxide, and barium oxide is 20a+o#% or more and 40yao1% or less, among titanium oxide, zirconium oxide, and tin oxide The content of at least one oxide (B group oxide) is 20 mo
More preferably, it is in the range of A% or more and 4011IO1% or less. This is because a glass dielectric constant of 12 or more and good fiber formability can be easily ensured.

When the silicon oxide content is 50 mol % or more, it is difficult to ensure a dielectric constant of 12 or more, and when it is less than 35 mol %, it is difficult to ensure good fiber formability.

If the amount of the group A oxide or the group B oxide is out of the range of 20 mol% or more and 40+io4% or less, it becomes difficult to ensure good fiber formability.

The lead-free glass having the composition shown in claim 2.3 is 15 yx
oj! For example, the following other oxides (hereinafter referred to as "Group 0 oxides"), Li20, N
atOlK, Ol Z n OX M n OS
Fe01BzOx, AlxOs, B
it Os , Flz Os , Ge0z
, TeOx, PgOs, V*O
s, NbzOs, TaxOs, LagOx
It may contain at least one of the following.

Note that if the content of group 0 oxides is 1511o1% or more, it becomes difficult to ensure a high relative dielectric constant, or fiber formability decreases.

Preferably, inorganic dielectric powder is dispersed in the resin of the composite dielectric of the present invention. As a specific inorganic dielectric powder, for example, B a T
iOs series, SrTiOx series, pbTi+/*
Z r l/l Ox system, P b (M g *yx
N b l/3) o, system, Ba (Snx Mgy
Taz ) Ox system, Ba (Zrx Zny Taz
) Those having a perovskite type crystal structure (or composite perovskite type crystal structure) such as those based on Os, and other inorganic compounds such as TiOx, ZrOx, and Snow alone and their composite oxides.

Usually, inorganic dielectric powder having a particle size of about 0.05 to 100 nm is used.

The usual method for dispersing into resin is to impregnate reinforcing material with resin in which inorganic dielectric powder has been previously dispersed. There is also a method in which the inorganic dielectric powder is dispersed in the resin.

The compounding ratio of the matrix resin, the reinforcing material made of glass, and the inorganic dielectric powder in the composite dielectric material (100 vot'%) of this invention is 10 to 95 volts of resin.

1%, reinforcing material 5-7Ovo1%, inorganic dielectric powder 0-7
It is about 0voj2% (usually 0 to 40vof%).

Applications of the composite dielectric of the present invention include, but are not limited to, substrates for printed circuit boards.

[For production]

In the composite dielectric material according to claims 1 to 4, since the glass reinforcing material has a high dielectric constant, it is easy to ensure a high dielectric constant of the composite dielectric material itself. Lead-free glass is also safe, with no concerns about lead poisoning.

As in the composite dielectric according to claim 2, the lead-free glass having a dielectric constant of 9 or more contains silicon oxide in an amount of 15 mol% or more and 60 m
ol% or less, group A oxide 0■O1% or more 40mof%
Hereinafter, if the group B oxide is contained in a proportion of Omoβ% or more and 55 mol% or less, and the total amount of these oxides (silicon oxide, A group oxide, and B1# oxide) is 8511oI1% or more, 9 or more Since it is easy to ensure the relative permittivity and fiber formability of the material, it is preferable for obtaining a reinforcing material with a high relative permittivity.

In the composite dielectric according to claim 3, in the lead-free glass, silicon oxide is contained in an amount of 35 mof% or more and 50 mol%.
Below, group A oxide is 20II+01% or more 40vao1
1% or less, Group B oxide 20IIIOI 1% or more 40I
When it is contained in a range of 1% or less of Iio, it is easy to ensure a dielectric constant of 12 or more and good fiber formability, so it is very preferable for obtaining a reinforcing material with a higher dielectric constant.

When an inorganic dielectric powder is used in combination as in the composite dielectric of claim 4, the high dielectric properties of the inorganic dielectric powder can be fully utilized, and the dielectric constant of the composite dielectric itself can easily reach 10 or more. Become.

〔Example〕

Next, the present invention will be explained in detail. Of course, the present invention is not limited to the following embodiments.

First, an example of manufacturing a lead-free glass fiber having a dielectric constant of 9 or more to be used as a reinforcing material will be described.

Raw materials such as oxides, carbonates, or hydroxides are blended to obtain a glass containing a predetermined proportion of oxides, placed in a platinum crucible, and heated in an electric furnace (conditions: 1450°C).
, 2 hours) and melt.

Next, the obtained melt was transferred to another platinum crucible with a nozzle that had been heated to a temperature where the melt viscosity was about 10" poise,
The glass fibers are pulled out from the nozzle on the back of the crucible to obtain glass fibers with a diameter of about 5 to 30 nm. Needless to say, the obtained glass fibers are then woven or cut into reinforcing materials such as glass cloth or fibers.

The dielectric constant and difficulty of fiber molding were investigated by changing the glass composition.

The relative permittivity was determined by making a bulk glass and measuring it with an impedance analyzer (measurement frequency IMHz). The results are shown in Table 1.2.

Regarding the difficulty of fiber molding, after holding the obtained melt in a platinum crucible at a temperature of about 108 poise for 24 hours,
I checked to see if the string could be pulled. When mass producing glass fiber, the melt is kept in a crucible made of platinum etc. for a long time (for example,
(approximately 20 hours). If a thread cannot be drawn even if the melt is kept in a crucible made of platinum or the like for a long time, there are limitations to the fiberizing method, such as forming fibers immediately after obtaining the melt. Glass samples numbered [Phase] to [Phase] could not be successfully formed into fibers after being held in the crucible for 24 hours.

Example 1 - As a reinforcing material, a 100 μm thick glass cloth made of glass fibers (fiber diameter 9 μm) having the composition of glass sample number (■) in Table 1 was prepared. On the other hand, 45 g of PPO resin was heated at 80°C.
After dissolving in 215g of toluene, Ba with an average particle size of 2n was dissolved.
A varnish in which 110 g of TiOs powder was added and dispersed was prepared.

The glass cloth was placed in the varnish, impregnated with the varnish, dried (115°C, 90 seconds), then stacked 4 times and heated to a temperature of 1.
A composite dielectric material having a thickness of approximately 0.8 strips was obtained by hot press molding at 80.degree. C., pressure of 50 kg/aJ, and 120 minutes.

The proportions of PPO resin, inorganic dielectric powder, and base material in the composite dielectric were 49vol% and 21vol%, respectively.
%, 30vo1%.

Example 2 - Composite dielectric was fabricated in the same manner as in Example 1, except that a glass cloth with a thickness of 100μ made of glass fibers (fiber diameter 9m) having the composition of glass sample number ■ in Table 1 was used as a reinforcing material. I got a body.

Example 3 - The same procedure as in Example 1 was used, except that a glass cloth with a thickness of 100 and n made of glass fibers (fiber diameter 9.W) having the composition of glass sample number ■ in Table 1 was used as the reinforcing material. A composite dielectric was obtained.

Example 4 A composite dielectric was prepared in the same manner as in Example 1, except that a glass cloth with a thickness of 100 nm made of glass fibers (fiber diameter 9.W) having the composition of glass sample number ■ in Table 2 was used as a reinforcing material. I got a body.

Example 5 - Composite dielectric material was prepared in the same manner as in Example 1, except that a glass cloth with a thickness of 100μ made of glass fibers (fiber diameter 9i1M) having the composition of glass sample number ■ in Table 2 was used as a reinforcing material. I got a body.

Comparative Example 1 - The glass constituting the glass cloth has a dielectric constant of about 6°7.
A composite dielectric material was obtained in the same manner as in Example 1 except that the material was glass.

Electrodes were provided on the front and back surfaces of each of the composite dielectrics of Examples and Comparative Examples, and the relative permittivity was measured using an impedance analyzer (measurement frequency IMtfz).

The measurement results are shown in Table 3.

The composite dielectric materials of Examples 1 to 5 in Table 3 all have relative dielectric constants exceeding 10. Comparing the dielectric constants of Examples 1 to 5 and Comparative Example 1, it is clear that the high dielectric constant of the reinforcing material is very effective in ensuring a high dielectric constant. In addition, PPO
The dielectric constant of the part made of resin and 13aTiOs powder was separately investigated and found to be 11.0, clearly proving that the reinforcing material does not hinder securing a high dielectric constant in the composite dielectric of this invention. It was done.

〔Effect of the invention〕

As described above, the composite dielectric of claims 1 to 4 can easily ensure a high dielectric constant of the composite dielectric itself because the reinforcing material made of glass has a high dielectric constant, and is lead-free. Glass is highly practical because it is safe and free from lead poisoning.

In addition, in the composite dielectric according to the second aspect, a reinforcing material having a high dielectric constant can be easily obtained, and therefore the composite dielectric can be easily manufactured, which is preferable.

In addition, in the composite dielectric according to the third aspect, it is easy to obtain a reinforcing material having a higher dielectric constant, and therefore the composite dielectric is easy to manufacture, which is very preferable.

In addition, the composite dielectric material according to the fourth aspect of the present invention can easily secure a high dielectric constant of 10 or more, so that it is very practical.

Claims (1)

[Scope of Claims] 1. In a composite dielectric material in which a resin is reinforced with a reinforcing material made of glass, at least a part of the glass constituting the reinforcing material is a lead-free glass having a dielectric constant of 9 or more. A composite dielectric material characterized by: 2 Lead-free glass with a dielectric constant of 9 or more contains silicon oxide of 1
5 mol% or more and 60 mol% or less, magnesium oxide,
0 mol% to 40 mol% of at least one oxide of calcium oxide, strontium oxide, and barium oxide, and 0 mol of at least one oxide of titanium oxide, zirconium oxide, and tin oxide.
The composite dielectric material according to claim 1, wherein the composite dielectric material contains 1% or more and 55 mol% or less, and the total amount of these oxides is 85 mol% or more. 3 Silicon oxide content is 35 mol% or more and 50 mol
% or less, the content of at least one oxide of magnesium oxide, calcium oxide, strontium oxide, and barium oxide is 20 mol% or more and 40 mol% or less, the content of at least one oxide of titanium oxide, zirconium oxide, and tin oxide is Content is 20mol%
3. The composite dielectric material according to claim 2, wherein the amount is in the range of 40 mol% or more. 4 Claim 1 wherein inorganic dielectric powder is dispersed in the resin
3. The composite dielectric material according to any one of 3 to 3.