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KR-102964440-B1 - Laminated glass ceramic dielectric material, sintered body, method for manufacturing a sintered body, and circuit member for high frequency

KR102964440B1KR 102964440 B1KR102964440 B1KR 102964440B1KR-102964440-B1

Abstract

The present invention provides a laminated glass ceramic dielectric material, a sintered body, and a circuit member for high frequency, having low dielectric properties and high mechanical strength in a high frequency range of 20 GHz or higher. The laminated glass ceramic dielectric material of the present invention has a laminated structure in which at least an outer layer, an inner layer, and an outer layer are stacked in that order, wherein the outer layer is made of a material having a relative dielectric constant of 5.5 or less at a measurement temperature of 25°C and a frequency of 28 GHz after sintering, and the inner layer is made of a material having a thermal expansion coefficient after sintering that is higher than the thermal expansion coefficient after sintering of the outer layer.

Inventors

  • 우마야하라 요시오

Assignees

  • 니폰 덴키 가라스 가부시키가이샤

Dates

Publication Date
20260512
Application Date
20220120
Priority Date
20210205

Claims (12)

  1. A laminated glass ceramic dielectric material characterized by having a laminated structure stacked in the order of at least an outer layer, an inner layer, and an outer layer, wherein the outer layer is made of a material having a specific dielectric constant of 5.5 or less at a measurement temperature of 25°C and a frequency of 28 GHz after sintering, and the outer layer contains at least amorphous glass powder, wherein the amorphous glass powder contains, as a glass composition, 70-80% SiO₂ , 15-30% B₂O₃ , and 0.1-5% Li₂O + Na₂O + K₂O (total amount of Li₂O , Na₂O , and K₂O ) in mass%, and further wherein the inner layer is made of a material having a thermal expansion coefficient after sintering that is higher than the thermal expansion coefficient after sintering of the outer layer.
  2. In paragraph 1, A laminated glass ceramic dielectric material characterized in that the inner layer is made of a material in which the coefficient of thermal expansion after sintering is 1.5 ppm/K or higher than the coefficient of thermal expansion after firing of the outer layer.
  3. In paragraph 1 or 2, A laminated glass ceramic dielectric material characterized in that the inner layer contains at least crystalline glass powder.
  4. In paragraph 1 or 2, A laminated glass ceramic dielectric material characterized by being provided for use in the form of a laminated green sheet.
  5. A sintered body obtained by sintering a laminated glass ceramic dielectric material described in claim 1 or 2, characterized in that one or more crystals selected from annolsite, Sr feldspar, celcyanide, diopside, and willmite are precipitated from the glass matrix of the inner layer.
  6. In paragraph 5, A sintered body characterized by the dielectric constant of the outer layer being 4 or less at a measured temperature of 25℃ and a frequency of 28 GHz.
  7. In paragraph 5, A sintered body characterized by having a ceramic powder content of less than 0.5 mass% in the outer layer.
  8. A sintered body integrated by stacking at least an outer layer, an inner layer, and an outer layer in that order, wherein the dielectric constant of the outer layer at a measurement temperature of 25°C and a frequency of 28 GHz is 5.5 or less, wherein the outer layer contains at least amorphous glass powder, and the amorphous glass powder contains, as a glass composition, 70-80 % SiO₂ , 15-30% B₂O₃ , and 0.1-5% Li₂O + Na₂O + K₂O (total amount of Li₂O , Na₂O , and K₂O ) in mass%, and further wherein the coefficient of thermal expansion of the inner layer is higher than the coefficient of thermal expansion of the outer layer.
  9. A method for manufacturing a sintered body characterized by firing a laminated glass ceramic dielectric material described in claim 1 or 2.
  10. In Paragraph 9, A method for manufacturing a sintered body characterized by firing at a temperature of 1000℃ or lower.
  11. A high-frequency circuit member having a dielectric layer, characterized in that the dielectric layer is a sintered body as described in claim 5.
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Description

Laminated glass ceramic dielectric material, sintered body, method for manufacturing a sintered body, and circuit member for high frequency [0001] The present invention relates to a laminated glass ceramic dielectric material having a low dielectric constant and high mechanical strength advantageous for signal processing in a high frequency range of 20 GHz or higher, a sintered body, and a circuit member for high frequency. [0002] Alumina ceramics are widely used as wiring boards or circuit components. Alumina ceramics have the disadvantage of slow signal processing speeds because they have a high dielectric constant of 10. In addition, they have the disadvantage of high conductor loss because they must use tungsten, which has a high melting point, as the conductor material. [0003] To compensate for these shortcomings, glass-ceramic dielectric materials composed of glass powder and ceramic powder are being developed, and their sintered bodies are being used as dielectric layers. For example, a glass-ceramic dielectric material sintered body using glass powder made of alkali borosilicate glass has a dielectric constant of 6 to 8, which is lower than that of alumina ceramic materials. In addition, since it can be fired at a temperature of 1000°C or lower, it has the advantage of being able to be fired simultaneously with low-melting-point metal materials such as Ag and Cu, which have low conductor loss, and thus can be used as inner layer conductors (see Patent Documents 1 and 2). [0027] In this specification, a numerical range indicated by “∼” means a range that includes the values described before and after “∼” as the minimum and maximum values, respectively. The laminated glass ceramic dielectric material of the present invention is a laminate stacked in the order of an outer layer, an inner layer, and an outer layer, and in particular, it is a laminate in which the inner layer contains crystalline glass powder and the outer layer contains amorphous glass powder. [0028] First, I will explain the inner layer. [0029] It is preferable that the glass powder constituting the inner layer contains crystalline glass powder that exhibits a higher coefficient of thermal expansion than the outer layer after firing. For example, it is preferable to use crystalline glass powder that has the property of precipitating one or more crystals selected from annolsite, Sr feldspar, celcyanide, diopside, and willemite upon firing. Glass ceramics in which the above crystals precipitate tend to have a high coefficient of thermal expansion and, furthermore, have high mechanical strength, so it is easy to increase the mechanical strength of the sintered body. In addition, the coefficient of thermal expansion of the inner layer glass ceramic after firing is, for example, about 6 to 11 ppm/K at 30 to 380°C. [0030] In addition, to increase the mechanical strength of the sintered body, it is desirable to include high-strength ceramic powder, such as alumina or zirconia, in the crystalline glass powder. When mixing the high-strength ceramic powder, it is desirable that the content of the crystalline glass powder be 50 to 80 mass% and the content of the high-strength ceramic powder be 20 to 50 mass%, and it is even more desirable that the content of the crystalline glass powder be 60 to 75 mass% and the content of the high-strength ceramic powder be 25 to 40 mass%. If the content of the high-strength ceramic powder is too high, it becomes difficult to densify the sintered body. On the other hand, if the amount of the high-strength ceramic powder is too low, the mechanical strength of the sintered body is prone to decrease. [0031] As a high-strength ceramic powder, other ceramic powders other than alumina and zirconia may be introduced. As other ceramic powders, one or more types selected from silicon carbide, silicon nitride and aluminum nitride may be used. [0032] The crystallization temperature T1 of the inner layer is preferably 850 to 900°C, particularly 870 to 900°C. If T1 is too low, the substrate becomes prone to bending. On the other hand, if T1 is too high, the firing temperature increases. [0033] The composition of the crystalline glass powder can be selected according to the crystal species to be precipitated. The crystalline glass powder in which annolsite is precipitated preferably contains, in mass% as the glass composition, 40-60 % SiO₂ , 1-20% Al₂O₃ , 15-30% CaO, and 0-10 % B₂O₃ . The crystalline glass powder in which Sr-based feldspar is precipitated preferably contains, in mass% as the glass composition, 20-40 % SiO₂ , 20-40% Al₂O₃ , 10-30% SrO, 10-20% MgO, and 0-10 % B₂O₃ . The crystalline glass powder in which celsian is precipitated preferably contains, as a glass composition in mass%, 35-60% SiO₂ , 1-10 % Al₂O₃ , 20-40% BaO, and 10-20% MgO. The crystalline glass powder in which diopside is precipitated preferably contains, as a glass composition in mass%, 40-60% SiO₂ , 0-10% Al₂O₃ , 10-25 % MgO, and 15-35% CaO. The