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

Porcelain composition

[0001] The present invention relates to a ceramic composition, and more particularly to a ceramic composition that can be turned into a high frequency dielectric ceramic by firing at a low temperature.

[0002] Alumina, crystallized glass ceramics, and the like are known as dielectric materials useful at high frequencies (particularly frequencies of 10 GHz or higher), and these are used as circuit board materials. Furthermore, ceramic compositions that are sintered at temperatures of about 800 to 1000°C, which is close to the melting point of metal wiring materials such as Ag and Au, are used as circuit board materials in order to be co-fired with the metal wiring materials.

[0003] As a ceramic 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 ceramic composition containing crystallized glass powder and alumina powder. Patent Document 2 also describes a ceramic composition containing MgO, SiO ２ and a porcelain composition containing a sintering aid component.

[0004] Patent No. 4470392 Patent No. 4202117

[0005] As a result of extensive research, the present inventors have found that forsterite (Mg ２ SiO ４ ) and / or enstatite (MgSiO ３ It has been found that when a ceramic composition having Ag as the main crystalline phase after firing is co-fired with Ag as a wiring material, Ag diffuses into the ceramic during firing and precipitates as Ag colloid after cooling, increasing the dielectric loss tangent of the ceramic. Circuit boards using such ceramic compositions have the problem of exhibiting characteristics that are significantly different from the designed circuit characteristics.

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

[0007] An object of the present invention is to provide a ceramic 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.

[0008] As a result of further intensive research, the inventors have found that forsterite (Mg ２ SiO ４ ) and / or enstatite (MgSiO ３ In the production of porcelain having SiO as the main crystalline phase, ２ , MgO, Li ２ O, Bi ２ O ３ , and B ２ O ３ The inventors have found that a ceramic composition containing the above essential components, with the oxide-equivalent contents of each component within a specific range, can suppress the generation and growth of Ag colloids and can also suppress an increase in the dielectric loss tangent due to co-firing with Ag as a wiring material, and have completed the present invention.

[0009] That is, the present invention relates to the following ceramic composition: 1. In mass % in terms of oxide, SiO ２ 46 to 68 mass%, MgO 20 to 49 mass%, Li ２ O 0.3 to 5 mass %, Bi ２ O ３ 0.6 to 15 mass% of B ２ O ３ Contains 0.3 to 12 mass% of Bi ２ O ３ and B ２ O ３ Mass ratio (Bi ２ O ３ / B ２ O ３ 2. In terms of oxide, the SiO ２ 50 to 64 mass %, MgO 24 to 45 mass %, Li ２ O 0.5 to 3 mass %, Bi ２ O ３ 0.8 to 8 mass% of B ２ O ３ Contains 0.5 to 4 mass % of Bi ２ O ３ and B ２ O ３ Mass ratio (Bi ２ O ３ / B ２ O ３Item 1. The ceramic composition according to Item 1, wherein SiO ２ 3. The ceramic composition according to any one of items 1 to 3, wherein the total content of MgO, CaO, ZnO, MnO, NiO, and CoO is 80 mass% or more. 4. The ceramic composition according to any one of items 1 to 3, which is for co-firing with Ag.

[0010] In the ceramic composition of the present invention, the generation and growth of Ag colloids are suppressed, and an increase in the dielectric loss tangent due to co-firing with Ag is suppressed.

[0011] 1. Porcelain Composition Porcelain produced by firing the porcelain composition of the present invention is forsterite (Mg ２ SiO ４ ) and / or enstatite (MgSiO ３ ) as the main crystalline phase. Hereinafter, for convenience, the composition of the ceramic composition will be expressed as an elemental oxide of a single element. The ceramic composition of the present invention is ２ , MgO, Li ２ O, Bi ２ O ３ , B ２ O ３ Each component and its content will be described below. In this specification, the content of each component in the ceramic composition is expressed in mass % converted to oxide.

[0012] The ceramic composition of the present invention contains, in mass % of oxides, SiO ２ 46 to 68 mass%, MgO 20 to 49 mass%, Li ２ O 0.3 to 5 mass %, Bi ２ O ３ 0.6 to 15 mass% of B ２ O ３ Contains 0.3 to 12 mass% of Bi ２ O ３ and B ２ O ３ Mass ratio (Bi ２ O ３ / B ２ O ３ ) is 10 or less.

[0013] The ceramic composition of the present invention having the above-mentioned constitution is ２ , MgO, Li２ O, Bi ２ O ３ , and B ２ O ３ Each of these is contained in a specific range of content, and Bi ２ O ３ and B ２ O ３ Mass ratio (Bi ２ O ３ / B ２ O ３ ) is 10 or less, the generation of Ag colloids is suppressed, and an increase in the dielectric loss tangent due to simultaneous firing with Ag as a wiring material can be suppressed.

[0014] (SiO ２ In the ceramic composition of the present invention, SiO ２ is the main component of porcelain. ２ The content of SiO is 46 to 68 mass % based on 100 mass % of the ceramic composition. ２ If the content is outside the above range, it becomes difficult to sinter at a low temperature. ２ The content is preferably 48 to 66 mass %, more preferably 50 to 64 mass %.

[0015] (MgO) In the ceramic composition of the present invention, MgO is the main component of the ceramic. The MgO content is 20 to 49 mass% based on 100 mass% of the ceramic composition. If the MgO content is outside this range, sintering at low temperatures becomes difficult. The MgO content is preferably 22 to 47 mass%, more preferably 24 to 45 mass%.

[0016] (Li ２ O) In the ceramic composition of the present invention, Li ２ O is a minor component that promotes sintering of porcelain. ２ The content of O is 0.3 to 5 mass % based on 100 mass % of the ceramic composition. ２ The O content is preferably 0.4 to 4 mass %, more preferably 0.5 to 3 mass %.

[0017] (Bi ２ O ３ In the ceramic composition of the present invention, Bi ２ O ３is a minor component that promotes sintering of porcelain. ２ O ３ The content of Bi is 0.6 to 15 mass % based on 100 mass % of the ceramic composition. ２ O ３ If the content of Bi exceeds 15% by mass, the generation and growth of Ag colloids is promoted, and the dielectric loss tangent increases when the Bi is co-fired with Ag. ２ O ３ The content is preferably 0.7 to 11 mass %, more preferably 0.8 to 8 mass %.

[0018] (B ２ O ３ In the ceramic composition of the present invention, B ２ O ３ is a minor component that inhibits the generation and growth of Ag colloids in porcelain when porcelain and Ag are co-fired. ２ O ３ The content of is 0.3 to 12 mass % based on 100 mass % of the ceramic composition. ２ O ３ If the content of B is outside the above range, the generation and growth of Ag colloids in the porcelain cannot be sufficiently suppressed when the porcelain and Ag are co-fired. ２ O ３ If the content of B exceeds 12, the water resistance of the sintered porcelain may decrease. ２ O ３ The content is preferably 0.4 to 6 mass %, more preferably 0.5 to 4 mass %.

[0019] In the ceramic composition of the present invention, Bi ２ O ３ and B ２ O ３ Mass ratio (Bi ２ O ３ / B ２ O ３ ) is 10 or less. If the mass ratio exceeds 10, the generation and growth of Ag colloids in the porcelain are not sufficiently suppressed, and an increase in the dielectric loss tangent due to co-firing with Ag cannot be suppressed. The mass ratio is preferably 7 or less, more preferably 6 or less.

[0020] (Optional Components) The ceramic composition of the present invention may contain optional components. Examples of optional components include at least one optional component selected from the group consisting of CaO, ZnO, MnO, NiO, and CoO. The optional component exhibits an action similar to that of MgO, the main component of porcelain, and can adjust various properties of the porcelain, such as adjusting the temperature dependence of the dielectric constant. When the optional component is at least one component selected from the group consisting of CaO, ZnO, MnO, NiO, and CoO, the content of the component, 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 ceramic composition.

[0021] When the ceramic composition of the present invention contains optional components, the components used as the main components of the above-mentioned ceramics, i.e., SiO ２ The total content of 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 ceramic composition. ２ It is preferable that the total content of SiO and MgO and the content of only a part of the optional components contained be within the above range. ２ It is preferable that the total content of MgO is within the above range.

[0022] The ceramic composition of the present invention contains, in mass % in terms of oxide, SiO ２ 50 to 64 mass %, MgO 24 to 45 mass %, Li ２ O 0.5 to 3 mass %, Bi ２ O ３ 0.8 to 8 mass% of B ２ O ３ Contains 0.5 to 4 mass % of Bi ２ O ３ and B ２ O ３ Mass ratio (Bi ２ O ３ / B ２ O３ ) is preferably 6 or less. When the ceramic composition of the present invention satisfies the above requirements, the generation and growth of Ag colloids are further suppressed, and an increase in the dielectric loss tangent due to co-firing with Ag as a wiring material can be further suppressed.

[0023] The ceramic composition of the present invention is not particularly limited in terms of the type of raw material as long as it can have the above-mentioned configuration. ２ A mixture of oxides of a single element such as MgSiO can also be used. ３ , Li ２ B ４ O ７ Also, compounds that serve as oxide supply sources (various hydroxides, carbonates, etc.) may be used.

[0024] The form of the ceramic composition of the present invention is not particularly limited, and it is preferably a powder obtained by mixing powders of the above oxides and the like, calcining them to cause a reaction in advance, and then pulverizing them again.

[0025] The 50% particle diameter (median diameter) of the ceramic composition of the present invention is not particularly limited, and for example, ５０ ) may be 0.01 to 10 μm. ５０ ) is a particle diameter of 50% (D ５０ ) is preferably 0.1 to 5.0 μm, more preferably 0.2 to 1.0 μm.

[0026] In the ceramic composition of the present invention, even when Ag ions are diffused, the generation and growth of Ag colloids are suppressed, and an increase in the dielectric loss tangent due to co-firing with Ag can be suppressed. That is, the ceramic composition of the present invention is preferably for co-firing with Ag.

[0027] The ceramic composition of the present invention contains Ag. ２ The dielectric loss tangent at 10 GHz of porcelain to which 1% by mass of O is added and which is densified by firing at a temperature of 800 to 1000° C. 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 with wavelengths of 400 to 500 nm, the generation and growth of Ag colloids occurs when Ag is added to the ceramic composition. ２ In addition to the method of measuring the dielectric loss tangent of porcelain fired with the addition of O, evaluation can be easily performed based on the color tone of the porcelain. For example, it can be evaluated that the lower the diffuse reflectance at a wavelength of 450 nm, the greater the amount of Ag colloid, and this index can be used to help design the composition of a porcelain composition. However, if the porcelain composition already exhibits a color darker than that produced by Ag colloid due to the inclusion of a large amount of coloring components such as MnO, CoO, or NiO, evaluation based on color tone is not appropriate, and evaluation by measuring the dielectric loss tangent is required.

[0029] The ceramic composition of the present invention can be used to manufacture a laminated substrate by a known method, for example, by forming green sheets by a doctor blade method or the like, printing a conductive paste on the surface of the sheets, laminating the sheets, pressing them together, and then firing them at a temperature of 800 to 1000°C to obtain a laminated substrate.

[0030] 2. Method for Producing Porcelain Composition The method for producing the porcelain composition of the present invention is not particularly limited. For example, as described above, powders of raw materials such as oxides are mixed, calcined to react in advance, and then pulverized again, thereby producing the porcelain composition of the present invention in powder form.

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

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

[0033] The method for pulverizing the calcined oxide or the like is not particularly limited, and for example, it can be pulverized by a method using a pulverizing device such as a bead mill, a jet mill, etc. After pulverization, the powder may be classified by a method such as air classification to adjust the particle size distribution.

[0034] The ceramic composition of the present invention can be produced by the production method described above.

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

[0036] (Production of Porcelain Composition) SiO ２ , Mg(OH) ２、 Li ２ CO ３ , Bi ２ O ３ , and Li ２ B ４ O ７ The raw material powders were mixed and pulverized so that the oxide-equivalent composition was the value shown in Table 1, to obtain a raw material mixed powder. The raw material mixed powder was fired at 850°C for 24 hours, and the fired product was pulverized again to obtain a 50% particle diameter (D ５０ The powder of the ceramic composition was produced with a 50% particle diameter (D ５０ ) was measured using a laser diffraction / scattering particle size distribution analyzer (model "MT-3300", manufactured by Nikkiso Co., Ltd.).

[0037] [Evaluation Method] Samples were prepared for the ceramic compositions produced in the Examples and Comparative Examples, and the following measurements were carried out.

[0038] (Preparation of Samples) The powder of the ceramic composition was compressed into a pellet shape and then fired at 900°C or 950°C for 1 hour to prepare a sintered body. ２ O and a powder of a ceramic composition: Ag ２ A powder of AgO mixed at a mass ratio of 99:1 was prepared, and similarly compressed into pellets, which were then fired. ２ O-doped Ag ２ An O-added sintered body was prepared.

[0039] Next, the sintered body and Ag ２ The surfaces of the O-doped sintered bodies were polished to prepare samples for measuring the diffuse reflectance. ２ Each of the O-added sintered bodies was ground and polished to a diameter of 15.5 mm and a height of 7.8 mm to prepare a sample for measuring dielectric properties.

[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 the measurement condition of an incident light angle of 10 degrees. ２ O ３ A standard white plate consisting of the above was used. Table 1 shows the measured values ​​at 450 nm.

[0041] (Dielectric Properties (Dielectric Constant, Dielectric Loss Tangent)) The dielectric properties, ie, the dielectric constant and dielectric loss tangent at 10 GHz, were measured by a measurement method conforming to JIS R1627 "Test Method for Dielectric Properties of Fine Ceramics for Microwave Use." The measurement was performed using a PNA Network Analyzer N5227A manufactured by Keysight Technologies.

[0042] The compositions and evaluation results of the examples and comparative examples are shown in Table 1.

[0043]

[0044] From the results in Table 1, in Comparative Examples 1 and 2, Ag ２ The diffuse reflectance of the sintered body to which 1% O was added was 22% or 34% (i.e., less than 50% in either case), whereas the diffuse reflectance of Examples 1 to 10 was 55 to 89% (i.e., 50% or more in either case), indicating that the generation of Ag colloids was suppressed.

[0045] In addition, Ag in Comparative Example 1 ２ The dielectric loss tangent of the sintered body containing 1% O was a high value of 0.0016. In contrast, the dielectric loss tangent of Example 1 was a low value of 0.0006, which indicates that the generation and growth of Ag colloids was suppressed in Example 1, thereby suppressing an increase in the dielectric loss tangent.

[0046] The ceramic composition of the present invention is useful as a wiring material to be co-fired with Ag, since the generation and growth of Ag colloids is suppressed and the increase in dielectric loss tangent due to co-firing with Ag is suppressed.

Claims

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

2. In terms of oxide, mass % SiO ２ 50 to 64% by mass, 24 to 45% by mass of MgO, Li ２ O is 0.5 to 3 mass %, Bi ２ O ３ 0.8 to 8 mass% B ２ O ３ 0.5 to 4 mass% Contains Bi ２ O ３ and B ２ O ３ Mass ratio to (Bi ２ O ３ / B ２ O ３ 2. The ceramic composition of claim 1, wherein the porcelain composition has a porcelain content of 100% or less.

3. SiO ２ 3. The ceramic composition according to claim 1 or 2, wherein the total content of MgO, CaO, ZnO, MnO, NiO and CoO is 80 mass % or more.

4. The ceramic composition according to any one of claims 1 to 3, which is for co-firing with Ag.