Porcelain composition

Abstract

The present invention provides a porcelain composition in which the generation and growth of Ag colloids is suppressed, and an increase in the dielectric loss tangent due to co-firing with Ag is suppressed.　The present invention provides a porcelain composition that contains, in terms of oxide equivalent mass%, 46-68 mass% of SiO2, 20-49 mass% of MgO, 0.3-5 mass% of Li2O, 0.6-15 mass% of Bi2O3, and 0.3-12 mass% of B2O3, wherein the mass ratio of Bi2O3 to B2O3 (Bi2O3 / B2O3) is 10 or less.

Description

Technical Field

[0001] The present invention relates to a porcelain composition, and particularly to a porcelain composition that becomes a dielectric porcelain for high frequencies by firing at a low temperature.

Background Art

[0002] Alumina, crystallized glass ceramics, etc. are known as dielectric materials useful at high frequencies (particularly frequencies of 10 GHz or higher), and these are used as circuit board materials. Further, as a circuit board material, a porcelain composition that is sintered at a temperature of about 800 to 1000 °C, which is close to the melting point of the metal wiring material such as Ag or Au, is used for co-firing with the metal wiring material.

[0003] As a porcelain composition that has low loss at high frequencies and is sintered at a temperature of about 800 to 1000 °C, for example, Patent Document 1 describes a porcelain composition containing crystallized glass powder and alumina powder, etc. Further, Patent Document 2 describes a porcelain composition containing MgO, SiO2, and a sintering aid component.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As a result of diligent research, the inventors have discovered that when a porcelain composition having forsterite (Mg2SiO4) and / or enstatite (MgSiO3) as the main crystalline phase after firing is fired simultaneously with Ag as a wiring material, the Ag element diffuses into the porcelain during firing and precipitates as Ag colloid after cooling, increasing the dielectric loss tangent of the porcelain. Circuit boards using such porcelain compositions have the problem of exhibiting characteristics that deviate significantly from the designed circuit characteristics.

[0006] Therefore, there is a need for the development of a porcelain composition in which the generation and growth of Ag colloids are suppressed, and the increase in dielectric loss tangent due to co-firing with Ag as a wiring material is suppressed.

[0007] The present invention aims to provide a porcelain composition in which the generation and growth of Ag colloids are suppressed, and the increase in dielectric loss tangent due to co-firing with Ag is suppressed. [Means for solving the problem]

[0008] As a result of further diligent research, the inventors have discovered that in the production of porcelain with forsterite (Mg2SiO4) and / or enstatite (MgSiO3) as the main crystalline phase, a porcelain composition in which SiO2, MgO, Li2O, Bi2O3, and B2O3 are essential components, and the oxide content of each component is within a specific range, can suppress the generation and growth of Ag colloids, and can suppress the increase in dielectric loss tangent due to co-firing with Ag as a wiring material, thus completing the present invention.

[0009] In other words, the present invention relates to the following porcelain composition. 1. In terms of mass percentage on an oxide basis, SiO2 at 46-68% by mass, MgO is 20-49% by mass. Li2O at 0.3-5% by mass, Bi2O3 in 0.6-15% by mass, 0.3-12% by mass of B2O3 Contains, The mass ratio of Bi2O3 to B2O3 (Bi2O3 / B2O3) is 10 or less. Porcelain composition. 2. In terms of mass percentage on an oxide basis, SiO2 in 50-64% by mass, MgO is 24-45% by mass. Li2O at 0.5-3% by mass, Bi2O3 at 0.8-8% by mass, 0.5-4% by mass of B2O3 Contains, The porcelain composition according to item 1, wherein the mass ratio of Bi2O3 to B2O3 (Bi2O3 / B2O3) is 6 or less. 3. The porcelain composition according to item 1 or 2, wherein the total content of SiO2, MgO, CaO, ZnO, MnO, NiO, and CoO is 80% by mass or more. 4. A porcelain composition according to any one of items 1 to 3, for co-firing with Ag. [Effects of the Invention]

[0010] The porcelain composition of the present invention suppresses the generation and growth of Ag colloids, and suppresses the increase in dielectric loss tangent due to co-firing with Ag. [Modes for carrying out the invention]

[0011] 1. Porcelain composition The porcelain produced by firing the porcelain composition of the present invention has a crystalline phase of forsterite (Mg2SiO4) and / or enstatite (MgSiO3) as the main crystalline phase. For convenience, the composition of the porcelain composition will be expressed below as an elemental oxide of a single element. The porcelain composition of the present invention contains SiO2, MgO, Li2O, Bi2O3, and B2O3. The following describes each component and its content. In this specification, the content of each component of the porcelain composition is expressed as mass % in terms of oxide.

[0012] The porcelain composition of the present invention is expressed in terms of mass % on an oxide basis. SiO2 at 46-68% by mass, MgO is 20-49% by mass. 0.3 to 5% by mass of Li2O, 0.6 to 15% by mass of Bi2O3, 0.3 to 12% by mass of B2O3 contained, and having a mass ratio of Bi2O3 to B2O3 (Bi2O3 / B2O3) of 10 or less, which is a porcelain composition.

[0013] The porcelain composition of the present invention having the above configuration contains SiO2, MgO, Li2O, Bi2O3, and B2O3 in respective specific content ranges, and the mass ratio of Bi2O3 to B2O3 (Bi2O3 / B2O3) is 10 or less, thereby suppressing the generation of Ag colloids and suppressing an increase in the dielectric tangent due to co-firing with Ag as a wiring material.

[0014] (SiO2) In the porcelain composition of the present invention, SiO2 is the main component of the porcelain. The content of SiO2 is 46 to 68% by mass based on 100% by mass of the porcelain composition. When the content of SiO2 is outside the above range, sintering at a low temperature becomes difficult. The content of SiO2 is preferably 48 to 66% by mass, and more preferably 50 to 64% by mass.

[0015] (MgO) In the porcelain composition of the present invention, MgO is the main component of the porcelain. The content of MgO is 20 to 49% by mass based on 100% by mass of the porcelain composition. When the content of MgO is outside the above range, sintering at a low temperature becomes difficult. The content of MgO is preferably 22 to 47% by mass, and more preferably 24 to 45% by mass.

[0016] (Li2O) In the porcelain composition of the present invention, Li2O is a sub-component that promotes the sintering of the porcelain. The content of Li2O is 0.3 to 5% by mass based on 100% by mass of the porcelain composition. The content of Li2O is preferably 0.4 to 4% by mass, and more preferably 0.5 to 3% by mass.

[0017] (Bi2O3) In the porcelain composition of the present invention, Bi2O3 is a minor component that promotes the sintering of porcelain. The Bi2O3 content is 0.6 to 15% by mass, based on 100% by mass of the porcelain composition. If the Bi2O3 content exceeds 15% by mass, it promotes the generation and growth of Ag colloids, and the dielectric loss tangent increases due to co-firing with Ag. The Bi2O3 content is preferably 0.7 to 11% by mass, and more preferably 0.8 to 8% by mass.

[0018] (B2O3) In the porcelain composition of the present invention, B2O3 is a minor component that suppresses the generation and growth of Ag colloids in the porcelain during the simultaneous firing of porcelain and Ag. The B2O3 content is 0.3 to 12% by mass, based on 100% by mass of the porcelain composition. If the B2O3 content is outside the above range, the suppression of the generation and growth of Ag colloids in the porcelain during the simultaneous firing of porcelain and Ag will not be sufficient. Furthermore, if the B2O3 content exceeds 12%, the water resistance of the sintered porcelain may decrease. The B2O3 content is preferably 0.4 to 6% by mass, and more preferably 0.5 to 4% by mass.

[0019] In the porcelain composition of the present invention, the mass ratio of Bi2O3 to B2O3 (Bi2O3 / B2O3) is 10 or less. If the above mass ratio exceeds 10, the generation and growth of Ag colloids in the porcelain will not be sufficiently suppressed, and the increase in dielectric loss tangent due to co-firing with Ag cannot be suppressed. The above mass ratio is preferably 7 or less, and more preferably 6 or less.

[0020] (optional ingredient) The porcelain composition of the present invention may contain optional components. Examples of optional components include at least one selected from the group consisting of CaO, ZnO, MnO, NiO, and CoO. These optional components exhibit effects similar to MgO as the main component of porcelain, and can adjust various properties such as the temperature dependence of the dielectric constant of the porcelain. When the optional component is at least one selected from the group consisting of CaO, ZnO, MnO, NiO, and CoO, the content of these components, i.e., the total content of CaO, ZnO, MnO, NiO, and CoO, is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of the porcelain composition.

[0021] If the porcelain composition of the present invention contains optional components, the total content of the components used as the main components of the porcelain as described above, namely SiO2, MgO, CaO, ZnO, MnO, NiO, and CoO, is preferably 80% by mass or more, more preferably 83% by mass or more, and even more preferably 86% by mass or more, based on 100% by mass of the porcelain composition. If the porcelain composition of the present invention contains only a portion of the optional components listed above, it is preferable that the sum of the content of SiO2 and MgO and the content of the portion of optional components contained is within the above range. Furthermore, even if the porcelain composition of the present invention does not contain the above optional components, it is preferable that the sum of the content of SiO2 and MgO is within the above range.

[0022] The porcelain composition of the present invention, in terms of mass % on an oxide basis, SiO2 in 50-64% by mass, MgO is 24-45% by mass. Li2O at 0.5-3% by mass, Bi2O3 at 0.8-8% by mass, 0.5-4% by mass of B2O3 Contains, It is preferable that the mass ratio of Bi2O3 to B2O3 (Bi2O3 / B2O3) is 6 or less. By satisfying the above requirements, the generation and growth of Ag colloids can be further suppressed, and the increase in dielectric loss tangent due to co-firing with Ag as a wiring material can be further suppressed.

[0023] The porcelain composition of the present invention is not particularly limited in terms of the type of raw materials, as long as it has the above-described structure. For example, a mixture of single-element elemental oxides such as SiO2 and MgO can be used. Alternatively, complex oxides such as MgSiO3 and Li2B4O7 may be used. Furthermore, compounds that serve as a source of oxides (various hydroxides, carbonates, etc.) may be used.

[0024] The form of the porcelain composition of the present invention is not particularly limited, but it is preferable that the powder be obtained by mixing the above-mentioned oxide or other powders, pre-reacting them by calcination, and then grinding them again.

[0025] The 50% particle size (median diameter) of the porcelain composition of the present invention is not particularly limited, for example, the 50% particle size (D 50 ) may be 0.01 to 10 μm. 50% particle size (D 50 The smaller the particle size (D), the lower the firing temperature at which sufficient sinterability can be achieved. 50 The particle size is preferably 0.1 to 5.0 μm, and more preferably 0.2 to 1.0 μm.

[0026] The porcelain composition of the present invention suppresses the generation and growth of Ag colloids even when Ag ions diffuse, and can suppress the increase in dielectric loss tangent due to co-firing with Ag. In other words, the porcelain composition of the present invention is preferably for co-firing with Ag.

[0027] The dielectric loss tangent at 10 GHz of the porcelain obtained by adding 1% by mass of Ag2O to the porcelain composition of the present invention and firing it at a temperature of 800 to 1000°C to densify it is preferably 0.0015 or less, more preferably 0.0010 or less, and even more preferably 0.0008 or less.

[0028] Since Ag colloids strongly absorb light at wavelengths of 400-500 nm, the generation and growth of Ag colloids can be easily evaluated by the color tone of the porcelain, in addition to the method of measuring the dielectric loss tangent of porcelain fired with Ag2O added to the porcelain composition. For example, a lower diffuse reflectance at a wavelength of 450 nm indicates a larger amount of Ag colloid, and this index can be used to design the composition of porcelain compositions. However, if the porcelain composition already exhibits a darker color than that produced by Ag colloids due to the presence of many coloring components such as MnO, CoO, and NiO, then evaluation by color tone is not appropriate, and evaluation by measuring the dielectric loss tangent is necessary.

[0029] The porcelain composition of the present invention can be used in the manufacture of laminated substrates by known methods. For example, a laminated substrate can be obtained by forming a green sheet using the doctor blade method, printing a conductive paste onto the sheet surface, laminating the sheets, pressing them together, and then firing them at a temperature of 800 to 1000°C.

[0030] 2. Method for manufacturing porcelain composition The manufacturing method for producing the porcelain composition of the present invention is not particularly limited. For example, the porcelain composition of the present invention can be produced in powder form by mixing powders such as oxides that serve as raw materials as described above, pre-firing them to allow them to react, and then grinding them again.

[0031] The calcination temperature is not particularly limited as long as it is a temperature at which the oxides and other raw materials can react, but is preferably 700 to 1000°C, and more preferably 750 to 900°C.

[0032] The calcination time is not particularly limited as long as the oxides and other raw materials can react, but is preferably 0.1 to 100 hours, and more preferably 1 to 30 hours.

[0033] The method for grinding the calcined oxides, etc., is not particularly limited and can be used, for example, by grinding using equipment such as a bead mill or a jet mill. Alternatively, the particle size distribution may be adjusted by classifying the powder after grinding using methods such as airflow classification.

[0034] The porcelain composition of the present invention can be manufactured by the manufacturing method described above. [Examples]

[0035] The present invention will be specifically described below with reference to examples and comparative examples. However, the present invention is not limited to the embodiments shown in the examples.

[0036] (Manufacturing of porcelain composition) Raw material powders: SiO2, Mg(OH) 2、 Li2CO3, Bi2O3, and Li2B4O7 were prepared. The above raw material powders were mixed and ground to obtain a raw material mixed powder so that the oxide composition was the value shown in Table 1. The raw material mixed powder was calcined at 850°C for 24 hours, and the calcined material was ground again to obtain a 50% particle size (D 50 A powder of a porcelain composition with particle size (D) = 0.5~0.6 μm was produced. 50 The particle size distribution was measured using a laser diffraction / scattering particle size analyzer (model "MT-3300", manufactured by Nikkiso Co., Ltd.).

[0037] [Evaluation Method] Samples were prepared from the porcelain compositions manufactured in the examples and comparative examples, and the following measurements were performed.

[0038] (Sample preparation) A porcelain composition powder was compressed into pellets and then fired at 900°C or 950°C for 1 hour to prepare a sintered body. Separately, a powder was prepared by mixing the porcelain composition powder with Ag2O in a mass ratio of porcelain composition powder:Ag2O = 99:1. This powder was similarly compressed into pellets and then fired to prepare an Ag2O-added sintered body.

[0039] Next, the surfaces of the sintered body and the Ag2O-added sintered body were polished to prepare samples for diffuse reflectance measurement. Separately, the sintered body and the Ag2O-added sintered body were ground and polished to a diameter of 15.5 mm and a height of 7.8 mm to prepare samples for dielectric property measurement.

[0040] (Diffuse reflectance) Using a spectrophotometer (model "U-3010," manufactured by Hitachi High-Technologies Corporation) equipped with an integrating sphere, diffuse reflected light, including specular reflection, was measured under measurement conditions of an incident light angle of 10 degrees. A standard white plate made of Al2O3 was used as the standard sample. Table 1 shows the measured values ​​at 450 nm.

[0041] (Dielectric properties (relative permittivity, dielectric loss tangent)) As dielectric properties, the relative permittivity and dielectric loss tangent at 10 GHz were measured according to the measurement method conforming to JIS R1627 "Test Method for Dielectric Properties of Microwave Fine Ceramics". The measurements were performed using a Keysight Technologies PNA network analyzer N5227A.

[0042] Table 1 shows the compositions and evaluation results of the examples and comparative examples.

[0043] [Table 1]

[0044] From the results in Table 1, it can be seen that in Comparative Examples 1 and 2, the diffuse reflectance of the sintered bodies with 1% Ag2O added was 22% or 34% (i.e., both less than 50%), whereas in Examples 1 to 10, the diffuse reflectance was 55 to 89% (i.e., all 50% or more), indicating that the generation of Ag colloid was suppressed.

[0045] Furthermore, the dielectric loss tangent of the sintered body with 1% Ag2O added in Comparative Example 1 was a high value of 0.0016. In contrast, the dielectric loss tangent of Example 1 was 0.0006, a low value, indicating that in Example 1, the generation and growth of Ag colloids were suppressed, and the increase in the dielectric loss tangent was suppressed. [Industrial applicability]

[0046] The porcelain composition of the present invention has suppressed generation and growth of Ag colloids, and the increase in dielectric loss tangent due to co-firing with Ag is suppressed, making it useful as a wiring material used in co-firing with Ag.

Claims

1. In terms of mass percentage on an oxide basis, SiO ２ 46-68% by mass, MgO in 20-49% by mass, Li ２ O is 0.3 to 5% by mass. Bi ２ O ３ 0.6 to 15% by mass, B ２ O ３ 0.3 to 12% by mass Contains, Bi ２ O ３ and B ２ O ３ The mass ratio of (Bi ２ O ３ / B ２ O ３ ) is 10 or less, The total content of CaO, ZnO, MnO, NiO, and CoO is 10% by mass or less, based on 100% by mass of the porcelain composition. The total content of SiO₂, MgO, CaO, ZnO, MnO, NiO, and CoO is 86% by mass or more. Porcelain composition.

2. In terms of mass percentage on an oxide basis, SiO ２ 50-64% by mass, MgO in 24-45% by mass, Li ２ O is 0.5 to 3% by mass. Bi ２ O ３ 0.8 to 8% by mass, B ２ O ３ 0.5 to 4% by mass Contains, Bi ２ O ３ and B ２ O ３ The mass ratio (Bi ２ O ３ / B ２ O ３ ) is 6 or less, The total content of SiO₂, MgO, CaO, ZnO, MnO, NiO, and CoO is 86% by mass or more. The porcelain composition according to claim 1.

3. SiO ２ The porcelain composition according to claim 1 or 2, wherein the total content of MgO, CaO, ZnO, MnO, NiO, and CoO is 90.8% by mass or more.

4. A porcelain composition according to any one of claims 1 to 3, for co-firing with Ag.

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