JP2008100866A - Crystallized glass, electric circuit board material containing crystallized glass, laminated circut board material, low temperature firing board material and high frequnecy circuit board material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide crystallized glass having low relative dielectric constant and low dielectric loss and used as an electric circuit board material, a laminated circuit board material, a low temperature firing board material and a high frequency circit board material. <P>SOLUTION: The crystallized glass has the crystal of a crystalline phase which contains Sr, specific dielectric constant of ≤9 in 1 MHz and dielectric loss of ≤10<SP>-2</SP>when a space group of the crystal is P-42<SB>1m</SB>, wherein the crystal of the crystalline phase is preferably akermanite. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to crystallized glass containing Sr (strontium), an electric circuit board material, a laminated circuit board material, a low-temperature fired board material, and a high-frequency circuit board material using the crystallized glass.

  2. Description of the Related Art Conventionally, the use frequency band has been rapidly increased with the improvement in performance of portable information terminals and the like, and there is a demand for higher density wiring, higher speed, and higher frequency. In order to meet such demands for high-speed signal transmission and high frequency, it is strongly required to reduce the dielectric constant and dielectric loss of the substrate material (dielectric layer). In other words, since the signal propagation delay time is proportional to the square root of the dielectric constant (ε), it is essential to lower the dielectric constant of the substrate material in order to transmit the signal at high speed. It is essential to lower the dielectric constant of the substrate material.

  The dielectric loss (tan δ) affects the signal transmission loss. The signal current is converted into thermal energy by the electromagnetic field generated in the substrate material in the vicinity of the circuit by the signal current, causing a transmission loss of the signal. Since this transmission loss is proportional to the dielectric loss and the square of the frequency, it increases as the frequency becomes higher. Therefore, low dielectric loss of the substrate material is indispensable for a high frequency substrate. Further, for high-speed signal propagation, it is necessary to shorten the wiring length, that is, to increase the circuit density. Therefore, it is desired to form a fine wiring or a three-dimensional wiring as much as possible on the substrate. Accordingly, in any case, the substrate surface needs to be as smooth as possible.

  Materials exhibiting a low dielectric constant and a low dielectric loss are also known, for example, for single crystals and ceramics. However, since single crystals are expensive, there is a problem that costs are high, and ceramics have problems that manufacturing processes such as compression, adjustment of a firing atmosphere, and mixing of trace additives are complicated.

For this reason, for example, in Patent Document 1, SiO ₂ is 45 to 65% by weight in terms of oxide, Al ₂ O ₃ is 20 to 30% by weight, CaO is 5 to 15% by weight, and MgO is 5 to 15% by weight. There is disclosed a ceramic substrate comprising a crystallized glass molded body having the following chemical composition, wherein the main crystal of the crystallized glass is anorthite, cordierite α and cordierite β.
JP-A-5-254863

  The ceramic substrate described in Patent Document 1 is manufactured by pressing particles into a mold to form a green compact, which is heated and allowed to react between solid phases. Although the reaction proceeds in the direction of eliminating the gaps between the particles that cause various characteristic deterioration in the sintered body, the gaps cannot be completely eliminated. Therefore, as long as the solid phase reaction, that is, the sintering method is used, there is a problem that there is a limit in principle in improving the characteristics.

  The present invention has been made to solve the above-described problems, and has a low relative dielectric constant and low dielectric loss, and an electric circuit board material, a laminated circuit board material, a low-temperature fired board material, and a high-frequency circuit. An object is to provide crystallized glass that can be used as a substrate material.

The present inventor has found that the crystallized glass containing Sr and having a crystal phase in the space symmetry of the space group P-42 ₁ m has a relative dielectric constant of 9 or less and a dielectric loss of 10 ^-2 or less. The present invention has been completed. More specifically, the present invention provides the following.

(1) Crystallized glass in which the space group of the crystal phase containing Sr has a spatial symmetry of P-42 ₁ m, the relative dielectric constant at 1 MHz is 9 or less, and the dielectric loss is 10 ⁻² % or less .

According to the crystallized glass of the invention of (1), when the spatial symmetry of the included crystal belongs to the space group P-42 ₁ m and contains Sr, the relative permittivity is low and the dielectric loss is also low. Can be small.

In this specification, the space group shown in Formula 1 is indicated as “P-42 ₁ m” for the sake of space.

  (2) The crystallized glass according to (1), wherein the crystal phase includes an akermanite type crystal.

(3) The chemical formula of the akermanite crystal is Sr ₂ AB ₂ O ₇ (A and B are selected from the group consisting of Si, Ge, Al, Ga, Zn, Mg, and Be) (2). The crystallized glass described in 1.

(4) The crystallized glass according to (2) or (3), wherein the chemical formula of the akermanite crystal is Sr ₂ MgSi ₂ O ₇ .

  According to the crystallized glass in the inventions of (2), (3) and (4), the dielectric constant can be reduced and the dielectric loss can be reduced by making the crystallized crystal of the akermanite type containing Sr. .

In this specification, the “Okermanite type” refers to a compound in which Ca of the mineral akermanite (Ca ₂ MgSi ₂ O ₇ ) is replaced with Sr, and the mineral has the same space group as the akermanite. Further, the portions corresponding to Mg and Si of the mineral akermanite can be appropriately replaced with Si, Ge, Al, Ga, Zn, Mg, and Be.

  (5) The crystallized glass according to any one of (1) to (4), wherein the average crystal particle diameter is 1 μm or less.

  According to the crystallized glass in the invention of (5), since the average crystal particle diameter is 1 μm or less, an ultra-smooth polished surface can be obtained. By uniformly depositing such fine crystals, the mechanical strength of the crystallized glass is improved.

  Here, the average crystal particle diameter refers to the particle diameter of the central cumulative value (“median diameter” d50) of the area standard of the diameter of 100 crystal particles measured by a transmission electron microscope (TEM).

(6)% by mass based on oxide,
SiO ₂ 37~47%
MgO 5-13% and SrO 42-54%
The crystallized glass according to any one of (1) to (5), containing

According to the crystallized glass in the invention of (6), a crystal phase composed of crystals having a space symmetry in which the space group containing Sr is P-42 ₁ m is selectively precipitated. In the crystallized glass of the present invention, the SiO ₂ component, MgO component, and SrO component play an important role in particular. That is, the SiO ₂ component, the MgO component, and the SrO component are extremely important components for precipitating crystals having a space group containing Sr as a crystal phase of P-42 ₁ m by heat treatment of the original glass.

(7) Further, in mass% based on oxide,
B ₂ O _{3 0~10%} and / or Al ₂ O _{3 0~10%} and / or P ₂ O _{5 0~10%} and / or GeO ₂ 0% and / or Ga ₂ O _{3 0~10%} And / or TiO ₂ 0-2% and / or ZrO ₂ 0-10% and / or ZnO 0-10% and / or CaO 0-10% and / or BaO 0-10% and / or Y ₂ O ₃ 0 10% and / or La ₂ O ₃ 0% and / or Sb ₂ O ₃ 0% and / or As ₂ O ₃ 0% and / or F 0%
The crystallized glass according to (6), containing

According to the crystallized glass in the invention of (7), B ₂ O ₃ , Al ₂ O ₃ , P ₂ O ₅ , GeO ₂ , Ga ₂ O ₃ , TiO ₂ , ZrO _2, ZnO, CaO, BaO, By containing Y ₂ O _3, La ₂ O _3, Sb ₂ O _3, As ₂ O ₃ and F, the original glass can be produced more stably.

  (8) By performing a nucleation step for 1 hour or more at 700 ° C. to 800 ° C. for the original glass and performing a crystal growth step by heat-treating at 800 ° C. to 950 ° C. for 0.5 hour or more after this nucleation step. The crystallized glass according to any one of (1) to (7) obtained.

  According to the crystallized glass in the invention of (8), the number of crystal nuclei is controlled by heat treatment at 700 ° C. to 800 ° C. for 1 hour or more, and then heat treatment is performed at 800 ° C. to 950 ° C. for 0.5 hour or more. To grow the nucleus into a crystal. Further, by controlling the nucleation step and the crystal growth step, as many desired crystals as possible can be generated in the crystallized glass. In addition, the size and number of crystals can be controlled.

  (9) The crystallized glass according to any one of (1) to (8), wherein the relative dielectric constant at 1 MHz is 5 or less.

  (10) An electric circuit board material comprising the crystallized glass according to any one of (1) to (9).

  (11) A laminated circuit board material comprising the crystallized glass according to any one of (1) to (9).

  (12) A low-temperature fired substrate material comprising the crystallized glass according to any one of (1) to (9).

  (13) A high-frequency circuit board material comprising the crystallized glass according to any one of (1) to (9).

According to the inventions of (10) to (13), the crystallized glass according to (1) to (9) has a relative dielectric constant of 1 or less at 1 MHz and a dielectric loss of 10 ⁻² % or less. Since the average crystal particle diameter of the crystal phase is fine, crystallized glass having desirable surface roughness, low relative permittivity and dielectric loss can be obtained only by polishing. Since the relative permittivity and dielectric loss are low, it can be used as an extremely good electric circuit board material, laminated circuit board material, low-temperature fired board material, and high-frequency circuit board material.

  According to the present invention, by reducing the relative dielectric constant, it is possible to suppress the extra electric flux entering the crystal phase, so that the dielectric loss can be reduced and the transmission speed can be increased. As a result, it is possible to provide an electric circuit board material, a laminated circuit board material, a low-temperature fired board material, and a high-frequency circuit board material having a low relative dielectric constant and low dielectric loss.

In the crystallized glass of the present invention, the space group of the crystal phase containing Sr has a spatial symmetry of P-42 ₁ m, the relative dielectric constant at 1 MHz is 9 or less, and the dielectric loss is 10 ^−2. % Or less.

  Hereinafter, embodiments of the crystallized glass of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. can do. In addition, although description may be abbreviate | omitted suitably about the location where description overlaps, the meaning of invention is not limited.

  In the present specification, the “oxide standard” means that oxides, carbonates, nitrates, etc. used as raw materials for the glass constituents of the present invention are all decomposed and converted into oxides when melted. In addition, the total oxide content is 100% by mass, and the content of each component contained in the glass is described.

[Crystallized glass]
The crystal phase of the crystallized glass of the present invention is not particularly limited as long as it contains Sr and the space group exhibits a spatial symmetry of P-42 ₁ m. As a crystal containing Sr and having a tetragonal system and a space group belonging to P-42 ₁ m, for example, an akermanite-type crystal can be exemplified.

The mineral akermanite (Ca ₂ MgSi ₂ O ₇ ) belongs to the melilite group in the solosilicate and is an alkaline earth silicate crystal. In this specification, an akermanite-type crystal (Sr ₂ AB ₂ O ₇ ) indicates a crystal having the same crystal structure as that of akermanite.

The chemical formula of the akermanite crystal is represented by Sr ₂ AB ₂ O ₇ , and A and B are selected from the group of Si, Ge, Al, Ga, Zn, Mg, and Be. A and B can be appropriately changed according to the purpose of use of the crystallized glass. However, when A is Mg and B is Si, a crystal having a lower relative dielectric constant and a lower dielectric loss. A glass can be obtained. A plurality of akermanite-type crystals in which A and B are different from each other may be precipitated, or may be singly.

As shown in FIGS. 1 and 2, the structure of the akermanite type crystal forms a layer perpendicular to the c-axis by sharing oxygen at each corner of the MgO ₄ tetrahedron and the two SiO ₄ tetrahedrons. . The layer perpendicular to the c-axis is a layered silicate laminated in the c-axis direction, and Ca ions are bonded between the layers. In the present invention, Ca is replaced with Sr, Mg is replaced with A in Sr ₂ AB ₂ O ₇ , and Si is replaced with B in Sr ₂ AB ₂ O ₇ . The broken lines in FIGS. 1 and 2 indicate that they are coupled downward toward the paper surface, and the solid lines indicate that they are coupled upward toward the paper surface. In the figure, black circles indicate oxygen, white circles indicate magnesium, and double circles indicate silicon.

In the present invention, the SiO ₂ component is also a useful component for producing a crystal having a space symmetry with a space group of P-42 ₁ m. If the SiO ₂ component is excessively contained, the glass component in the crystallized glass increases, and therefore the dielectric constant tends to increase. Further, when the SiO ₂ component is insufficient, it is difficult to melt, and in some cases, it may not vitrify. Therefore, the lower limit of the SiO ₂ component is preferably 37%, more preferably 39%, and most preferably 41%. Further, the upper limit of the SiO ₂ component is preferably 47%, more preferably 44%, and most preferably 43%.

  The MgO component is a useful component as one of the selective species of the constituent components of the precipitated crystal while improving the melting property of the glass. If the MgO component is contained excessively, the crystals obtained are unstable and the structure tends to be coarsened. Further, when the MgO component is insufficient, products other than the akermanite type crystal phase are likely to be generated. Therefore, the lower limit of the MgO component is preferably 5%, more preferably 7%, and most preferably 8%. The upper limit of the MgO component is preferably 13%, more preferably 11%, and most preferably 10%.

  The SrO component is a useful component that constitutes crystals, and at the same time, is a component that is effective in improving meltability and stability in the production of the current glass. Moreover, by replacing Ca of akermanite with Sr, the dielectric constant and dielectric loss are reduced, which contributes to the improvement of characteristics as a circuit board. On the other hand, when the SrO component is contained excessively, the stability of the glass tends to be lowered. Therefore, the lower limit of the SrO component is preferably 42%, more preferably 45%, and most preferably 47%. The upper limit value of the SrO component is preferably 54%, more preferably 50%, and most preferably 49%.

The B ₂ O ₃ component is an optional component that has the effect of improving the meltability of the glass. However, when it is excessively contained, it becomes difficult to precipitate a desired crystal. Therefore, the upper limit value of the B ₂ O ₃ component is preferably 10%, more preferably 8%, and most preferably 5%.

The Al ₂ O ₃ component is an optional component useful for improving the chemical durability and mechanical hardness of the crystallized glass. The type of precipitated crystals varies depending on the heat treatment conditions, but in order to precipitate crystals containing Sr and a space group having a spatial symmetry of P-42 ₁ m even when various heat treatment conditions are taken into consideration. The upper limit of the Al ₂ O ₃ component is preferably 10%, more preferably 8%, and most preferably 5%.

The P ₂ O ₅ component is a useful optional component that acts as a crystal nucleating agent for glass. However, if contained excessively, the raw glass causes milky white devitrification, so the upper limit of the P ₂ O ₅ component is It is preferably 10%, more preferably 8%, and most preferably 5%.

GeO ₂ component is an optional component that same function as the SiO ₂ component, it is possible to replace some or all of the SiO ₂ component. However, since the GeO ₂ component is expensive, the upper limit is preferably 10%, more preferably 8%, and most preferably 5%.

The Ga ₂ O ₃ component is a component that is effective in improving the meltability, chemical durability, and hardness of the glass surface. Although it is a component that can be optionally added, it is particularly introduced in the form of replacing a part of the SiO ₂ component. The upper limit of the Ga ₂ O ₃ component is preferably 10%, preferably 8%, and most preferably 5%.

The TiO ₂ component is an optional component that can be a crystal nucleation agent. Appropriate use is useful from the viewpoint of controlling the crystal grain size, but excessive addition tends to increase the dielectric constant. Therefore, the upper limit of the TiO ₂ component is preferably 2%, more preferably 1%, and most preferably 0.2%.

ZrO ₂ and ZnO components are optional components that can be crystal nucleating agents, and are components that are effective in improving the meltability of glass and the stability of glass. It becomes easy. Therefore, the upper limit of both ZrO ₂ and ZnO components is preferably 10%, more preferably 8%, and most preferably 5%.

  The CaO component is a component that can be a crystal component and is an optional component that has the effect of improving the meltability of the glass. However, when it is excessively contained, devitrification tends to occur. Therefore, the upper limit of the CaO component is preferably 10%, more preferably 8%, and most preferably 5%.

  The BaO component is a crystal component and is also an optional component that increases the stability of the glass. However, if it is excessively contained, the stability of the glass tends to be lowered. Therefore, the upper limit of the BaO component is preferably 10%, more preferably 8%, and most preferably 5%.

Since the Li ₂ O component, the Na ₂ O component, and the K ₂ O component impart electrical conductivity, the dielectric properties are likely to be hindered. Therefore, it is preferable not to contain the Li ₂ O component, the Na ₂ O component, and the K ₂ O component.

The Y ₂ O ₃ component is an optional component that is effective in improving the chemical durability of the glass and the hardness of the glass surface. However, if it is excessively contained, the stability of the glass tends to be lowered. Therefore, the upper limit value of the Y ₂ O ₃ component is preferably 10%, more preferably 8%, and most preferably 5%.

The La ₂ O ₃ component is an optional component that is effective in improving the chemical durability of the glass and the hardness of the glass surface, but if it is contained excessively, the stability of the glass tends to be lowered. Therefore, the upper limit value of the La ₂ O ₃ component is preferably 10%, more preferably 8%, and most preferably 5%.

The Sb ₂ O ₃ component is an optional component that is effective in defoaming glass melt. The Sb ₂ O ₃ component needs to take measures for environmental measures when glass is manufactured, processed, and discarded. Therefore, the upper limit value of the Sb ₂ O ₃ component is preferably 10%, more preferably 8%, and most preferably 5%.

The As ₂ O ₃ component is an optional component effective for defoaming glass melt. As ₂ O ₃ component needs to take measures on environmental measures when manufacturing, processing, and disposing of glass. Therefore, the upper limit of the As ₂ O ₃ component is preferably 10%, more preferably 8%, and most preferably 5%.

  The F (fluorine) component is an optional component that is effective in improving the meltability and stability of the glass. However, when the F component is excessively contained, the stability of the glass is significantly lowered. Therefore, the upper limit value of the F component is preferably 10%, more preferably 8%, and most preferably 5%.

[Relative permittivity and dielectric loss]
The crystallized glass of the present invention has a low relative dielectric constant of 9 or less at 1 MHz and a low dielectric loss of 10 ⁻² % or less. Since the propagation delay time of the signal is proportional to the square root of the dielectric constant (ε), if the relative dielectric constant exceeds 9, the signal cannot be transmitted at high speed. Therefore, it is preferably 9 or less, more preferably 6 or less, and most preferably 5 or less. The dielectric loss (tan δ) affects the signal transmission loss. The signal current is converted into thermal energy by the electromagnetic field generated in the substrate material in the vicinity of the circuit by the signal current, causing a transmission loss of the signal. Since this transmission loss is proportional to the dielectric loss and the square of the frequency, the signal attenuates when the dielectric loss exceeds 10 ⁻² %. In addition, the dielectric loss is preferably 10 ⁻² % or less, and more preferably 10 ⁻³ % or less.

[Usage]
The crystallized glass of the present invention can be used for, for example, an electric circuit board material, a laminated circuit board material, a low-temperature fired board material, and a high-frequency circuit board material. These crystallized glasses can be used in the form of being combined with other dielectrics in the form of powder, paste, etc., in addition to being used alone for the above-described use of the substrate material. Specifically, there are applications such as a dielectric substrate having a pattern electrode formed on the substrate, a laminated substrate material, a dielectric resonant element, a firing aid for the dielectric material, and a dielectric paste.

[Method for producing crystallized glass]
The crystallized glass of the present invention is not particularly limited as long as it is a method for producing a normal crystallized glass. For example, it can be produced by the following method. A predetermined amount of each starting material (oxide, carbonate, nitrate, phosphate, sulfate, etc.) is weighed and mixed uniformly. The mixed raw materials are put into a gold crucible, a platinum crucible, a platinum alloy crucible or an iridium crucible, and dissolved in a melting furnace at 1400 to 1500 ° C. with stirring for 1 to 4 hours. Then, it casts into a metal mold | die etc. and anneals over 3-12 hours in the temperature range of 500-600 degreeC, and obtains the original glass for crystallized glass preparation.

  Thereafter, in order to crystallize the original glass, the crystal nucleation temperature is 700 to 800 ° C., the nucleation time is 1 to 20 hours, and the number of crystal nuclei is controlled (nucleation step). At this time, if the crystal nucleus forming temperature is less than 700 ° C., it is difficult to form crystal nuclei. On the other hand, if the temperature exceeds 800 ° C., growth occurs simultaneously with the formation of crystal nuclei, so that it is difficult to control the number of nucleations and the crystal grain size.

Furthermore, in order to grow crystal nuclei precipitated in the nucleation step, the crystallization temperature is set to 800 to 950 ° C., and the crystallization time is heat-treated for 0.5 to 10 hours to grow crystals (crystal growth step). If the crystallization temperature is less than 800 ° C., it is difficult to expect crystal growth. On the other hand, when the temperature exceeds 950 ° C., abnormal grain growth tends to occur.
After the crystal growth process, the crystallized glass that has been returned to room temperature still has strain due to the difference in thermal expansion between the crystal and the residual glass. Therefore, the final crystallized glass is obtained by finally annealing in the temperature range of 500 to 600 ° C. for 3 to 12 hours.

  The molded product of crystallized glass after the annealing step may be polished as necessary. In addition, it does not specifically limit about the grinding | polishing method, For example, it can grind | polish using synthetic abrasive grains, such as a synthetic diamond, silicon carbide, aluminum oxide, and boron carbide, and natural abrasive grains, such as a natural diamond and a cerium oxide.

The crystal phase of the crystallized glass thus crystallized by the heat treatment contains Sr and exhibits a space symmetry of P-42 ₁ m in the space group. At this time, the average crystal particle diameter of the crystal of the crystal phase is preferably 1 μm or less. By setting the average crystal particle diameter to 1 μm or less, crystallized glass excellent in strength and surface smoothness can be easily obtained. When the average crystal particle diameter exceeds 1 μm, not only the mechanical strength of the glass is easily lowered, but also the crystal surface roughness is easily deteriorated by causing crystal loss during polishing. The average crystal particle diameter is more preferably 0.5 μm or less. By uniformly depositing such fine crystals, it becomes easy to improve the mechanical strength of the crystallized glass, and it becomes easy to obtain a crystallized glass excellent in strength and surface smoothness.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to a following example.

[Example 1]
In the composition shown in Table 1, the raw materials were weighed so that the total amount was 400 g and mixed uniformly. Next, the mixture was melted at 1500 ° C. for 4 hours using a platinum crucible, and then rapidly cooled by casting into a metal mold. Annealing was performed at 550 ° C. for 6 hours to remove the distortion of the original glass. Thereafter, the glass was heat-treated at 800 ° C. for 3 hours to control the number of crystal nuclei, and then the crystal was grown at 900 ° C. for 12 hours to produce a plate-like crystallized glass.

[Example 2]
The composition shown in Table 1 was used in the same manner as in Example 1 except that the temperature in the glass melting condition, the temperature in the nucleation step, the temperature in the crystal growth step, and the time were changed.

[Example 3]
The composition shown in Table 1 was used in the same manner as in Example 1 except that the temperature and time in the nucleus growth step were changed.

  The glasses obtained in Examples 1 to 3 were cut into 40 mm × 40 mm and processed into parallel flat plates by double-side polishing. Thereafter, electrodes having both end surfaces made of gold were vapor-deposited, and the relative dielectric constant (ε) and dielectric loss (tan δ) at a frequency of 1 MHz at 25 ° C. were determined by an impedance analyzer (SI1260 manufactured by Solartron). A magnetron sputtering apparatus (SC-701HMC manufactured by Sanyu Electronics Co., Ltd.) was used for film formation. Moreover, the composition of the glass is indicated by mass%. The dielectric loss (tan δ) is also displayed. The results are shown in Table 1.

  In addition, Comparative Example 1 containing 64% exceeding 54% which is a preferable upper limit of SrO, Comparative Example 2 containing 30% less than 37% which is a preferable lower limit of SiO2, and 13% which is a preferable upper limit of MgO are included. Table 1 also shows the results of Comparative Example 3 containing 16% in excess.

From Table 1, in Examples 1 to 3, all the akermanite-type crystals were precipitated in the crystal phase and had the same crystal structure as that of the akermanite. In addition, in Examples 1 to 3, low dielectric constant and low dielectric loss are shown, while in Comparative Example 3, the relative dielectric constant shows a high value of 10, which is 9 or more. Further, Comparative Examples 1 and 2 could not be vitrified, and crystallized glass could not be obtained unless SiO ₂ was contained to some extent.

It is the figure which looked at the structure of the akermanite type crystal from the top. It is the figure which looked at the structure of the akermanite type crystal from the side.

Claims (13)

A crystallized glass in which a space group of crystal phases containing Sr has a spatial symmetry of P-42 _{1 m} , a relative dielectric constant at 1 MHz is 9 or less, and a dielectric loss is 10 ⁻² % or less.   The crystallized glass according to claim 1, wherein the crystal phase includes an akermanite type crystal. The chemical formula of the akermanite-type crystal is Sr ₂ AB ₂ O ₇ (A and B are selected from the group of Si, Ge, Al, Ga, Zn, Mg, and Be). Crystallized glass. The crystallized glass according to claim 2 or 3, wherein a chemical formula of the akermanite crystal is Sr ₂ MgSi ₂ O ₇ .   The crystallized glass according to any one of claims 1 to 4, wherein an average crystal particle diameter is 1 µm or less. % By mass based on oxide,
SiO ₂ 37~47%
MgO 5-13% and SrO 42-54%
The crystallized glass according to claim 1, comprising: Furthermore, in mass% based on oxide,
B ₂ O _{3 0~10%} and / or Al ₂ O _{3 0~10%} and / or P ₂ O _{5 0~10%} and / or GeO ₂ 0% and / or Ga ₂ O _{3 0~10%} And / or TiO ₂ 0-2% and / or ZrO ₂ 0-10% and / or ZnO 0-10% and / or CaO 0-10% and / or BaO 0-10% and / or Y ₂ O ₃ 0 10% and / or La ₂ O ₃ 0% and / or Sb ₂ O ₃ 0% and / or As ₂ O ₃ 0% and / or F 0%
The crystallized glass according to claim 6 containing.   The raw glass was obtained by performing a nucleation step at 700 ° C. to 800 ° C. for 1 hour or longer and, after this nucleation step, performing a crystal growth step by heat treatment at 800 ° C. to 950 ° C. for 0.5 hour or longer. The crystallized glass according to any one of claims 1 to 7.   The crystallized glass according to any one of claims 1 to 8, wherein a relative dielectric constant at 1 MHz is 5 or less.   An electric circuit board material comprising the crystallized glass according to claim 1.   A laminated circuit board material comprising the crystallized glass according to claim 1.   A low-temperature fired substrate material comprising the crystallized glass according to any one of claims 1 to 9.   A high-frequency circuit board material comprising the crystallized glass according to claim 1.

Images