TW202137395A - Low-k material and method for manufacturing the same - Google Patents

Abstract

A method of forming low-k material is provided, which includes providing a plurality of core-shell particles, the core of the core-shell particles has a first ceramic with low melting point, and the shell of the core-shell particles has a second ceramic with low melting point and low dielectric constant. The core-shell particles are sintered and molded to form a low-k material, wherein the shell of the core-shell particles is connected to form a network structure of microcrystal phase.

Description

Low dielectric material and its forming method

This disclosure relates to low dielectric materials and methods of forming them.

In response to the gradual emergence of 5G mobile broadband communications in ICT/IoT, wearable electronics, and green energy applications, it has begun to drive the domestic high-frequency industry such as millimeter wave substrates, materials/components and module integration and other related markets to flourish. In order to achieve full 5G applications (4G or 5G sub-6 GHz and 5G mmWave), LTCC components and packaging powders with low temperature sintering, low dielectric, low loss and low resonant frequency temperature drift coefficient should be developed to achieve a small size Low Temperature Co-fired Ceramic (LTCC) packaging technology that is compatible with millimeter wave high frequency and low loss requirements, low water absorption and high heat dissipation.

The method for forming a low-dielectric material provided by some embodiments of the present disclosure includes: providing a plurality of core-shell particles, the core of the core-shell particles has a first ceramic with a low melting point, and the shell layer of the core-shell particles has a low melting point and a low melting point. Dielectric constant second ceramic; sintering core-shell particles to form a low-dielectric material, wherein the shell layers of the core-shell particles are connected to form a network structure of microcrystalline phase.

In some embodiments, the first ceramic of the core includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, and zinc oxide, wherein the weight ratio of silicon oxide to magnesium oxide is 100:0 to 100:85, wherein The weight ratio of silicon oxide to aluminum oxide is 100:20 to 100:150, wherein the weight ratio of silicon oxide to calcium oxide is 100:2 to 100:20, and the weight ratio of silicon oxide to boron oxide is 100:2 to 100 : 70, and the weight ratio of silicon oxide to zinc oxide is 100:2 to 100:70.

In some embodiments, the first ceramic of the core includes silicon oxide, aluminum oxide, calcium oxide, and boron oxide, wherein the weight ratio of silicon oxide to aluminum oxide is 100:15 to 100:25, and the weight ratio of silicon oxide to calcium oxide The weight ratio is 100:10 to 100:25, and the weight ratio of silicon oxide to boron oxide is 100:30 to 100:50.

In some embodiments, the second ceramic of the shell layer includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide, wherein the weight ratio of silicon oxide to magnesium oxide is 100: 15 to 100:40, where the weight ratio of silicon oxide to aluminum oxide is 100:35 to 100:90, where the weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, where the weight of silicon oxide and boron oxide The ratio is 100:5 to 100:25, wherein the weight ratio of silicon oxide to bismuth oxide is 100:2 to 100:15, and the weight ratio of silicon oxide to titanium oxide is 100:0.2 to 100:25, and the weight ratio of silicon oxide is 100:0.2 to 100:25. The weight ratio to copper oxide is 100:0.2 to 100:15.

In some embodiments, the second ceramic of the shell layer includes silicon oxide, aluminum oxide, calcium oxide, boron oxide, and lithium oxide, wherein the weight ratio of silicon oxide to aluminum oxide is 100:90 to 100:110, and silicon oxide The weight ratio to calcium oxide is 100:0.2 to 100:10, wherein the weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, and the weight ratio of silicon oxide to lithium oxide is 100:90 to 100: 110.

In some embodiments, the molar ratio of the first ceramic of the core to the second ceramic of the shell is between 100:0.1 and 100:10.

In some embodiments, the melting point of the first ceramic of the core is 700°C to 900°C, the melting point of the second ceramic of the shell layer is 760°C to 910°C, and the melting point of the second ceramic is greater than the melting point of the first ceramic.

In some embodiments, the temperature of sintering the core-shell particles is 800°C to 900°C.

In some embodiments, the dielectric constant of the second ceramic of the shell layer is less than 6.

In some embodiments, the core-shell particles have a particle size of 0.3 micrometers (μm) to 3 micrometers.

In some embodiments, the above method further includes adding a plurality of alumina particles when sintering the core-shell particles to disperse the low-dielectric material including alumina particles, wherein the weight ratio of the core-shell particles to the alumina particles is 100:25. To 100:45, and the particle size of alumina particles is 50 nm to 2 µm.

In some embodiments, the dielectric constant of the low-k material is 3 to 5.

The low-dielectric material provided by an embodiment of the present disclosure includes: a first ceramic with a low melting point, dispersed in a connected second ceramic with a low melting point and a low dielectric constant, and the second ceramic has a microcrystalline phase net状结构。 Like structure.

In some embodiments, the first ceramic includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, and zinc oxide, wherein the weight ratio of silicon oxide to magnesium oxide is 100:0 to 100:85, and silicon oxide The weight ratio to alumina is 100:20 to 100:150, wherein the weight ratio of silicon oxide to calcium oxide is 100:2 to 100:20, and the weight ratio of silicon oxide to boron oxide is 100:2 to 100:70 , And the weight ratio of silicon oxide to zinc oxide is 100:2 to 100:70.

In some embodiments, the first ceramic includes silicon oxide, aluminum oxide, calcium oxide, and boron oxide, wherein the weight ratio of silicon oxide to aluminum oxide is 100:15 to 100:25, and the weight ratio of silicon oxide to calcium oxide It is 100:10 to 100:25, and the weight ratio of silicon oxide to boron oxide is 100:30 to 100:50.

In some embodiments, the second ceramic includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide, wherein the weight ratio of silicon oxide to magnesium oxide is 100:15 to 100 : 40, where the weight ratio of silicon oxide to aluminum oxide is 100:35 to 100:90, where the weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, where the weight ratio of silicon oxide to boron oxide is 100 :5 to 100:25, where the weight ratio of silicon oxide to bismuth oxide is 100:2 to 100:15, where the weight ratio of silicon oxide to titanium oxide is 100:0.2 to 100:25, and where silicon oxide and copper oxide The weight ratio is 100:0.2 to 100:15.

In some embodiments, the second ceramic includes silicon oxide, aluminum oxide, calcium oxide, boron oxide, and lithium oxide, wherein the weight ratio of silicon oxide to aluminum oxide is 100:90 to 100:110, and silicon oxide and calcium oxide The weight ratio is 100:0.2 to 100:10, wherein the weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, and the weight ratio of silicon oxide to lithium oxide is 100:90 to 100:110.

In some embodiments, the molar ratio of the first ceramic to the second ceramic is 100:0.1 to 100:10.

In some embodiments, the melting point of the first ceramic is 700°C to 900°C, the melting point of the second ceramic is 760°C to 910°C, and the melting point of the second ceramic is greater than the melting point of the first ceramic.

In some embodiments, the dielectric constant of the second ceramic is less than 6.

In some embodiments, the low dielectric material further includes a plurality of alumina particles dispersed therein, wherein the ratio between the total weight of the first ceramic and the second ceramic and the weight of the alumina particles is 100:25 to 100:45, And the particle size of alumina particles is 50 nm to 2 µm.

In some embodiments, the dielectric constant of the low-k material is 3 to 5.

The method for forming a low-k material provided by some embodiments of the present disclosure includes providing a plurality of core-shell particles 100 shown in FIG. 1. The core of the core-shell particle 100 has a first ceramic 101 with a low melting point, and the shell of the core-shell particle 100 has a second ceramic 103 with a low melting point and a low dielectric constant.

In some embodiments, the core first ceramic 101 includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, and zinc oxide. Wherein, the weight ratio of silicon oxide to magnesium oxide is 100:0 to 100:85, for example, 100:1 to 100:80, 100:5 to 100:75, 100:10 to 100:70, or 100:15 to 100:60 etc., but not limited to this. If the proportion of magnesium oxide is too low, the melting point will be too high, and sintering and forming will not be possible. If the proportion of magnesium oxide is too high, the melting point is too low, and it is easy to melt and cannot be matched with the LTCC process. The weight ratio of silica to alumina is 100:20 to 100:150, for example, 100:25 to 100:125, 100:30 to 100:130, 100:40 to 100:140, or 100:20 to 100: 120 etc., but not limited to this. If the proportion of alumina is too low, dielectric loss is likely to occur. If the proportion of alumina is too high, the melting point will be too high, and sintering and forming will not be possible. The weight ratio of silicon oxide to calcium oxide is 100:2 to 100:20, such as 100:3 to 100:18, 100:5 to 100:15, or 100:6 to 100:12, but not limited to this. If the ratio of calcium oxide is too low, the melting point will be too high, and sintering and forming will not be possible. If the proportion of calcium oxide is too high, the melting point will be too low and will easily melt and cannot be matched with the LTCC process. The weight ratio of silicon oxide to boron oxide is 100:2 to 100:70, for example, 100:5 to 100:65, 100:6 to 100:60, or 100:8 to 100:50, but not limited thereto. If the proportion of boron oxide is too low, the melting point will be too high, and sintering and forming will not be possible. If the proportion of boron oxide is too high, the melting point will be too low, which is easy to melt and cannot be matched with the LTCC process. The weight ratio of silicon oxide to zinc oxide is 100:2 to 100:70, for example, 100:5 to 100:65, 100:6 to 100:60, or 100:8 to 100:50, but not limited thereto. If the proportion of zinc oxide is too low, the melting point will be too high, and sintering and forming will not be possible. If the proportion of zinc oxide is too high, the melting point is too low, and it is easy to melt and cannot be matched with the LTCC process. If the melting point of the first ceramic is too high, in addition to being unable to be sintered and formed to match the LTCC process, it cannot be matched with the melting point of the second ceramic to form a core-shell particle structure.

In one embodiment, the core first ceramic 101 includes silicon oxide, aluminum oxide, calcium oxide, and boron oxide. The weight ratio of silicon oxide to aluminum oxide is 100:15 to 100:25, such as 100:15 to 100:20, or 100:20 to 100:25, but not limited thereto. If the proportion of alumina is too low, dielectric loss is likely to occur. If the proportion of alumina is too high, the melting point is too high and sintering cannot be formed. The weight ratio of silicon oxide to calcium oxide is 100:10 to 100:25, for example, 100:10 to 100:15, 100:15 to 100:20, 100:20 to 100:25, or 100:12 to 100: 22 and so on, but not limited to this. If the ratio of calcium oxide is too low, the melting point is too high and sintering cannot be formed. If the proportion of calcium oxide is too high, the melting point will be too low and will easily melt and cannot be matched with the LTCC process. The weight ratio of silicon oxide to boron oxide is 100:30 to 100:50, for example, 100:30 to 100:40, 100:40 to 100:50, 100:32 to 100:48, or 100:35 to 100: 45 and so on, but not limited to this. If the proportion of boron oxide is too low, the melting point will be too high, and sintering and forming will not be possible. If the proportion of boron oxide is too high, the melting point will be too low, which is easy to melt and cannot be matched with the LTCC process. If the melting point of the first ceramic is too high, in addition to being unable to be sintered and formed to match the LTCC process, it cannot be matched with the melting point of the second ceramic to form a core-shell particle structure.

In one embodiment, the second ceramic 103 of the shell layer includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide. The weight ratio of silicon oxide to magnesium oxide is 100:15 to 100:40, for example, about 100:20 to 100:40, 100:15 to 100:35, 100:18 to 100:38, or 100:20 to 100: 35 etc., but not limited to this. If the proportion of magnesium oxide is too low or too high, the cordierite crystal phase cannot be formed. The weight ratio of silica to alumina is 100:35 to 100:90, for example about 100:35 to 100:85, 100:40 to 100:80, 100:35 to 100:75, or 100:30 to 100: 70 etc., but not limited to this. If the proportion of alumina is too low or too high, the cordierite crystal phase cannot be formed. The weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, for example, about 100:0.5 to 100:10, 100:1 to 100:10, 100:2 to 100:10, or 100:0.5 to 100: 5 and so on, but not limited to this. If the proportion of calcium oxide is too low, the fluxing effect will be poor and the sintering temperature will be high. If the ratio of calcium oxide is too high, cordierite crystal phase cannot be formed. The weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, for example, about 100:5 to 100:20, 100:10 to 100:25, or 100:15 to 100:25, but not limited thereto. If the proportion of boron oxide is too low or too high, the cordierite crystal phase cannot be formed. The weight ratio of silicon oxide to bismuth oxide is 100:2 to 100:15, for example, about 100:2 to 100:12, 100:5 to 100:15, or 100:5 to 100:10, but not limited thereto. If the proportion of bismuth oxide is too low, the fluxing effect will be poor and the sintering temperature will be high. If the proportion of bismuth oxide is too high, the cordierite crystal phase cannot be formed. The weight ratio of silicon oxide to titanium oxide is 100:0.2 to 100:25, for example, about 100:0.5 to 100:20, 100:1 to 100:15, or 100:5 to 100:25, but not limited thereto. If the proportion of titanium oxide is too low, the crystallinity is poor and phase formation is difficult. If the proportion of titanium oxide is too high, the cordierite crystal phase cannot be formed. The weight ratio of silicon oxide to copper oxide is 100:0.2 to 100:15, such as about 100:0.5 to 100:15, 100:1 to 100:10, or 100:2 to 100:12, etc., but is not limited thereto. If the proportion of copper oxide is too low, the fluxing effect will be poor and the sintering temperature will be high. If the proportion of copper oxide is too high, the cordierite crystal phase cannot be formed.

In one embodiment, the second ceramic 103 of the shell layer includes silicon oxide, aluminum oxide, calcium oxide, boron oxide, and lithium oxide. The weight ratio of silicon oxide to aluminum oxide is 100:90 to 100:110, such as about 100:90 to 100:100, 100:100 to 100:110, or 100:95 to 100:105, but not limited thereto. If the proportion of alumina is too low or too high, the eucryptite crystal phase cannot be formed. The weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, for example, about 100:0.5 to 100:10, 100:1 to 100:10, or 100:0.5 to 100:5, but not limited thereto. If the proportion of calcium oxide is too low, the fluxing effect will be poor and the sintering temperature will be high. If the proportion of calcium oxide is too high, the eucryptite crystal phase cannot be formed. The weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, for example, about 100:5 to 100:20, 100:10 to 100:25, or 100:10 to 100:20, but not limited thereto. If the proportion of boron oxide is too low or too high, the eucryptite crystal phase cannot be formed. The weight ratio of silicon oxide to lithium oxide is 100:90 to 100:110, for example, about 100:90 to 100:100, 100:100 to 100:110, or 100:95 to 100:105, but not limited thereto. If the proportion of lithium oxide is too low or too high, the eucryptite crystal phase cannot be formed.

In an embodiment, the molar ratio of the first ceramic 101 of the core to the second ceramic 103 of the shell is 100:0.1 to 100:10, for example, about 100:0.2 to 100:8, 100:0.5 to 100:10 , 100:1 to 100:5, or 100:0.5 to 100:5, etc., but not limited to this. If the proportion of the second ceramic 103 is too low or the thickness of the shell layer is too thin, the dielectric constant will be high and the dielectric loss will be high. If the proportion of the second ceramic 103 is too high or the thickness of the shell layer is too thick, the dielectric constant and the dielectric loss will not be optimized, and the amount of the second ceramic material added will be wasted.

In an embodiment, the melting point of the first ceramic 101 of the core is 700°C to 900°C, for example, about 720°C to 820°C, 750°C to 900°C, or 720°C to 850°C, but not limited thereto. The melting point of the second ceramic 103 of the shell layer is 760°C to 910°C, for example, about 760°C to 860°C, 800°C to 900°C, or 780°C to 850°C, but not limited thereto. If the melting point of the two ceramic materials is too low or too high, the subsequent processing temperature of the material will not be compatible with the LTCC process. In addition, the melting point of the second ceramic 103 is greater than the melting point of the first ceramic 101. If the melting point of the first ceramic 101 is greater than or equal to the melting point of the second ceramic 103, the porosity of the material is increased, and the dielectric loss is increased.

In an embodiment, the dielectric constant of the second ceramic 103 of the shell layer is less than 6, for example, about 1, 2, 3, 4, or 5, but it is not limited thereto. If the dielectric constant of the second ceramic 103 is too high, the subsequent low dielectric constant material cannot be formed. In one embodiment, the particle size of the core-shell particles 100 is between 0.3 μm and 3 μm, such as about 0.3 μm to 2.5 μm, 0.5 μm to 3 μm, 0.5 μm to 2 μm, or 1 μm to 2.5 μm, etc., But it is not limited to this. If the core-shell particles 100 are too small or too large, the material is not easy to be used in the doctor blade process, and it is difficult to integrate into the LTCC process.

In an embodiment of the present disclosure, the method of forming the core-shell particles 100 is a sol-gel method. For example, the particles of the first ceramic 101 used in the core can be combined with a variety of oxide sources used in the second ceramic 103 (such as aluminum nitrate, magnesium nitrate, tetraethoxysilane, n-butyl titanate, boric acid, A solution of bismuth nitrate, copper nitrate, calcium nitrate, or a combination of the above) is mixed to form a sol, then the sol is heated to form a gel, and then the gel is dried and ground to form a powder. The powder can then be further processed at a high temperature to form core-shell particles 100. It is worth noting that those skilled in the art can use a suitable process to form the core-shell particles 100, and it is not limited to the above-mentioned sol-gel method.

Then, the core-shell particles are sintered to form a low-dielectric material 200, as shown in FIG. 2. The second ceramic 103 of the shell layer of the core-shell particle 100 will be connected into a microcrystalline phase network structure 201, and the first ceramic 101 will be dispersed in the connected second ceramic 103. In an embodiment, the temperature of sintering the core-shell particles 100 is 800° C. to 900° C., such as about 820° C., 830° C., 850° C., 870° C., or 880° C., but is not limited thereto. If the sintering temperature is too low, the material will have many defects, and the dielectric constant and dielectric loss will be high. If the sintering temperature is too high, the material will melt and cannot be shaped.

In one embodiment, the above method further includes adding a plurality of alumina particles 301 when the core-shell particles 100 are sintered, so that the low dielectric material 300 includes alumina particles 301 dispersed therein, as shown in FIG. 3. In some embodiments, the weight ratio of the core-shell particles 100 to the alumina particles 301 is 100:25 to 100:45, for example, about 100:25 to 100:40, 100:30 to 100:45, or 100:30 to 100:40 etc., but not limited to this. The addition of alumina particles 301 can further reduce the cost of the low dielectric material 300. If the ratio of alumina particles 301 is too high, the dielectric constant will increase. In one embodiment, the particle size of the alumina particles 301 is 50 nm to 2 µm, for example, about 100 nm to 2 µm, 200 nm to 2 µm, 500 nm to 1.8 µm, 500 nm to 1.5 µm, or 800 nm to 1.5 µm. 1.5 µm etc., but not limited to this. If the particle size of the alumina particles 301 is too small, the strength of the fired material will be insufficient. If the particle size of the alumina particles 301 is too large, the network structure will be broken and the dielectric constant will increase.

In one embodiment, the dielectric constant of the low dielectric material obtained by the above process is 3 to 6, such as about 3.5, 4, 4.5, 5, 5.5, or 6, etc., but it is not limited thereto.

In order to make the above content and other purposes, features, and advantages of this disclosure more obvious and understandable, the following specifically enumerates preferred embodiments, which are described in detail in conjunction with the accompanying drawings: [ Examples ]

Example 1 Al(NO ₃ ) ₃ • 9H ₂ O (FW=375.14, 20.54 g, 54.8 mmol), Mg(NO ₃ ) ₂ • 6H ₂ O (FW=256.41, 6.14 g, 23.9 mmol), Si( C ₂ H ₅ O) ₄ (FW=208.33, 14.35 mL, 64.3 mmol), Ti(C ₄ H ₉ O) ₄ (FW=340.32, 0.077 mL, 0.217 mmol), dissolve in absolute ethanol, and put After filling glass A (which contains about 50 parts by weight of MgO, about 38.6 parts by weight of _{Al 2} O _{3 , about 100 parts by weight of SiO 2} and an average molecular weight of about 57.4) as the main component, stir until uniform to obtain Liquid A. The modifier H ₃ BO ₃ (FW=61.83, 0.9328 g, 15 mmol), Bi(NO ₃ ) ₃ •5H ₂ O (FW=485.07, 0.7299 g, 1.5 mmol), Cu(NO ₃ ) ₂ •2.5 Add H ₂ O (FW=232.59, 1.3308 g, 5.7 mmol), Ca(NO ₃ ) ₂ •4H ₂ O (FW=236.15, 0.2211 g, 0.94 mmol) to the mixture of absolute ethanol and deionized water, and stir well , And adjust the pH to 9.23 with ammonia water to obtain Liquid B. The liquid A and B are mixed and evenly stirred to obtain a sol.

Next, the sol was placed in an oven at 40°C and allowed to stand for sol-gelation to obtain a gel, then the gel was dried in an environment of 80°C, taken out and ground into powder, and placed at 250°C to maintain the temperature After 3 hours, the temperature is raised to 750°C for 2 hours. After cooling, it is ground into powder to obtain an LTCC powder with a core-shell structure. The core (glass A) and the shell (containing silicon oxide, magnesium oxide, The molar ratio of aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide) is 94:6.

Take an appropriate amount of powder ^{and press it into a round blank with a diameter of 11 mm under the condition of a pressure of 40 kg/m 2} , and hold the temperature at 850 ℃ for 2 hours to connect the shell layers of the core-shell particles into a microcrystalline phase network structure. The above product has a density of 2.71 g/cm ³ , a dielectric constant Dk of 4.72 (1GHz), and a dielectric loss Df of 3.4×10 ^-4 (1GHz). The measurement standard for the above density is CNS3299-3, and the measurement standard for dielectric constant and dielectric loss is IPC-TM-650.

Example 2 Al(NO ₃ ) ₃ • 9H ₂ O (FW=375.14, 35.75 g, 95.3 mmol), Mg(NO ₃ ) ₂ • 6H ₂ O (FW=256.41, 10.69 g, 41.7 mmol), Si( C ₂ H ₅ O) ₄ (FW=208.33, 23.24 mL, 104.2 mmol), Ti(C ₄ H ₉ O) ₄ (FW=340.32, 0.1353 mL, 0.398 mmol), dissolve it in absolute ethanol, and put it in After filling glass A (which contains about 50 parts by weight of MgO, about 38.6 parts by weight of _{Al 2} O _{3 , about 100 parts by weight of SiO 2} and an average molecular weight of about 57.4) as the main component, stir until uniform to obtain Liquid A. The modifier H ₃ BO ₃ (FW=61.83, 1.6237 g, 26.2 mmol), Bi(NO ₃ ) ₃ •5H ₂ O (FW=485.07, 1.2705 g, 2.62 mmol), Cu(NO ₃ ) ₂ •2.5 H ₂ O (FW=232.59, 2.3166 g, 9.96 mmol), Ca(NO ₃ ) ₂ •4H ₂ O (FW=236.15, 0.385 g, 1.63 mmol) were added to the mixture of absolute ethanol and deionized water, and stirred well , And adjust the pH to 9.23 with ammonia water to obtain Liquid B. The liquid A and B are mixed and evenly stirred to obtain a sol.

Next, the sol was placed in an oven at 40°C and allowed to stand for sol-gelation to obtain a gel, then the gel was dried in an environment of 80°C, taken out and ground into powder, and placed at 250°C to maintain the temperature After 3 hours, the temperature is raised to 750°C for 2 hours. After cooling, it is ground into powder to obtain an LTCC powder with a core-shell structure. The core (glass A) and the shell (containing silicon oxide, magnesium oxide, The molar ratio of aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide) is 90:10.

Take an appropriate amount of powder ^{and press it into a round blank with a diameter of 11 mm under the condition of a pressure of 40 kg/m 2} , and hold the temperature at 850 ℃ for 2 hours to connect the shell layers of the core-shell particles into a microcrystalline phase network structure. The above product has a density of 2.72 g/cm ³ , a dielectric constant Dk of 5.13 (1GHz), and a dielectric loss Df of 5.4×10 ^-4 (1GHz). The measurement standard for the above density is CNS3299-3, and the measurement standard for dielectric constant and dielectric loss is IPC-TM-650.

Example 3 Al(NO ₃ ) ₃ • 9H ₂ O (FW=375.14, 5.19 g, 13.9 mmol), Mg(NO ₃ ) ₂ • 6H ₂ O (FW=256.41, 1.55g, 6.1 mmol), Si( C ₂ H ₅ O) ₄ (FW=208.33, 3.37 mL, 15.1 mmol), Ti(C ₄ H ₉ O) ₄ (FW=340.32, 0.019 mL, 0.0536 mmol), dissolve it in absolute ethanol, and put it in After filling glass B (containing the main components of B ₂ O ₃ about 47.2 parts by weight, Al ₂ O ₃ about 105.5 parts by weight, SiO ₂ about 100 parts by weight, and average molecular weight of about 72.5), stir until uniform to obtain Liquid A. The modifier H ₃ BO ₃ (FW=61.83, 0.118 g, 1.9 mmol), Bi(NO ₃ ) ₃ • 5H ₂ O (FW=485.07, 0.066 g, 0.14 mmol), Cu(NO ₃ ) ₂ • 2.5 H ₂ O (FW=232.59, 0.336 g, 1.4 mmol), Ca(NO ₃ ) ₂ •4H ₂ O (FW=236.15, 0.056 g, 0.2 mmol) were added to the mixture of absolute ethanol and deionized water, and stirred well , And adjust the pH to 9.23 with ammonia water to obtain Liquid B. The liquid A and B are mixed and evenly stirred to obtain a sol.

Next, the sol was placed in an oven at 40°C and allowed to stand for sol-gelation to obtain a gel, then the gel was dried in an environment of 80°C, taken out and ground into powder, and placed at 250°C to maintain the temperature After 3 hours, the temperature is raised to 750°C for 2 hours. After cooling, it is ground into powder to obtain an LTCC powder with a core-shell structure. The core (glass B) and the shell (containing silicon oxide, magnesium oxide, The molar ratio of aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide) is 98:2.

Take an appropriate amount of powder ^{and press it into a round blank with a diameter of 11 mm under the condition of a pressure of 40 kg/m 2} , and hold the temperature at 850 ℃ for 2 hours to connect the shell layers of the core-shell particles into a microcrystalline phase network structure. The density of the above product is 2.66 g/cm ³ , the dielectric constant Dk is 3.21 (11GHz), the dielectric loss Df is 2.21×10 ^-3 (11GHz), and the temperature coefficient of resonance frequency τf is -0.20 (20 ^o C~100 ^o C, DC=1V). The measurement standard of the above density is CNS3299-3, the measurement standard of dielectric constant and dielectric loss is IPC-TM-650, and the measurement method of the temperature coefficient of resonance frequency can refer to Journal of the Ceramic Society of Japan 122 [6] , page 492-495, 2014.

Example 4 Al(NO ₃ ) ₃ • 9H ₂ O (FW=375.14, 5.83 g, 15.5 mmol), Mg(NO ₃ ) ₂ • 6H ₂ O (FW=256.41, 1.74 g, 6.7 mmol), Si( C ₂ H ₅ O) ₄ (FW=208.33, 3.39 mL, 15.2 mmol), Ti(C ₄ H ₉ O) ₄ (FW=340.32, 0.022 mL, 0.062 mmol), dissolve it in absolute ethanol, and put it in Filling glass C (contains about 37.21 parts by weight of _{B 2} O _{3 , about 21.39 parts by weight of Al 2} O ₃ , about 19.01 parts by weight of CaO, _{about 100 parts by weight of SiO 2} and an average molecular weight of about 65.7) after stirring until Evenly, liquid A is obtained. The modifier H ₃ BO ₃ (FW=61.83, 0.265 g, 4.28 mmol), Bi(NO ₃ ) ₃ •5H ₂ O (FW=485.07, 0.2073 g, 0.427 mmol), Cu(NO ₃ ) ₂ •2.5 H ₂ O (FW=232.59, 0.378 g, 1.625 mmol), Ca(NO ₃ ) ₂ • 4H ₂ O (FW=236.15, 0.063 g, 0.267 mmol) were added to the mixture of absolute ethanol and deionized water, and stirred well , And adjust the pH to 9.23 with ammonia water to obtain Liquid B. The liquid A and B are mixed and evenly stirred to obtain a sol.

Next, the sol was placed in an oven at 40°C and allowed to stand for sol-gelation to obtain a gel, then the gel was dried in an environment of 80°C, taken out and ground into powder, and placed at 250°C to maintain the temperature After 3 hours, the temperature is raised to 750°C for 2 hours, and then ground into powder after cooling. A core-shell structure of LTCC powder can be obtained. The core (glass C) and shell layer (containing silicon oxide, magnesium oxide, The molar ratio of aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide) is 98:2.

Take an appropriate amount of powder ^{and press it into a round blank with a diameter of 11 mm under the condition of a pressure of 40 kg/m 2} , and hold the temperature at 850 ℃ for 2 hours to connect the shell layers of the core-shell particles into a microcrystalline phase network structure. The density of the above product is 2.37 g/cm ³ , the dielectric constant Dk is 4.7 (1GHz), and the dielectric loss Df is 1.5*10 ^-3 (1GHz). The measurement standard for the above density is CNS3299-3, and the measurement standard for dielectric constant and dielectric loss is IPC-TM-650.

Comparative Example 1 The glass A of Example 1 was pressed into a round blank with a diameter of 11 mm under the condition of a ^{pressure of 40 kg/m 2, and the temperature was maintained at 850° C. for 2 hours.} The density of the above product is 3.13 g/cm ³ , the dielectric constant Dk is 5.79 (1GHz), and the dielectric loss Df is 1.3×10 ^-3 (1GHz). The measurement standard for the above density is CNS3299-3, and the measurement standard for dielectric constant and dielectric loss is IPC-TM-650.

Comparative Example 2 The glass B of Example 3 was pressed into a round blank with a diameter of 11 mm under the condition of a ^{pressure of 40 kg/m 2, and the temperature was maintained at 850° C. for 2 hours.} The density of the above product is 2.63 g/cm ³ , the dielectric constant Dk is 5.29 (1GHz), 4.95 (11GHz), the dielectric loss Df is 7×10 ^-5 (1GHz), 2×10 ^-3 (11GHz), The temperature coefficient of resonance frequency τf is 2.99 (20 ^o C~100 ^o C, DC=1V). The measurement standard of the above density is CNS3299-3, the measurement standard of dielectric constant and dielectric loss is IPC-TM-650, and the measurement method of the temperature coefficient of resonance frequency can refer to Journal of the Ceramic Society of Japan 122 [6] , page 492-495, 2014.

Comparative Example 3 The glass C of Example 4 was pressed into a round blank with a diameter of 11 mm under the condition of a ^{pressure of 40 kg/m 2, and the temperature was maintained at 850° C. for 2 hours.} The above product has a density of 2.35 g/cm ³ , a dielectric constant Dk of 4.91 (1GHz), and a dielectric loss Df of 1.5×10 ^-3 (1GHz). The measurement standard for the above density is CNS3299-3, and the measurement standard for dielectric constant and dielectric loss is IPC-TM-650.

The core-shell molar ratio, density, dielectric constant Dk, dielectric loss Df, and temperature coefficient of resonance frequency τf of the products of the foregoing Examples 1-4 and Comparative Examples 1-3 were compared with Table 1 below.

Table 1 Core shell molar ratio (composition) Product density (g/cm ³ ) Dielectric constant Dk Dielectric loss Df Resonance frequency temperature coefficient τf Example 1 94:6 (glass A/cordierite) 2.71 4.72 (1GHz) 3.4×10 ^-4 (1GHz) - Example 2 90:10 (glass A/cordierite) 2.72 5.13 (1GHz) 5.4×10 ^-4 (1GHz) - Example 3 98:2 (glass B/cordierite) 2.66 3.21 (11GHz) 2.21×10 ^-3 (11GHz) -0.20 Example 4 98:2 (glass C/cordierite) 2.37 4.7 (1GHz) 1.5×10 ^-3 (1GHz) - Comparative example 1 glass A 3.13 5.79 (1GHz) 1.3×10 ^-3 (1GHz) - Comparative example 2 glass B 2.63 5.29 (1GHz) 4.95 (11GHz) 7×10 ^-5 (1GHz) 2×10 ^-3 (11GHz) 2.99 Comparative example 3 glass C 2.35 4.91 (1GHz) 1.5×10 ^-3 (1GHz) -

From the examples and comparative examples shown in Table 1, it can be seen that in terms of dielectric constant, the dielectric constant of core-shell particles after sintering molding is significantly lower than that of only the core material, and the reduction range can reach more than 10-20% (Examples 1-4 and Comparative Example 1-3). In terms of dielectric loss, the dielectric loss of core-shell particles after sintering is mostly lower than that of core materials alone, or at least can be maintained at the same level (Examples 1-4 and Comparative Examples 1-3).

Please continue to refer to Table 1. Regarding the temperature coefficient of resonance frequency, glass B (Comparative Example 2) has a positive resonance frequency temperature coefficient τf=2.99 (20 ^o C~100 ^o C), and cordierite has a negative resonance frequency temperature coefficient τf =-12.61 (20 ^o C~100 ^o C), through the core-shell structure design of the present invention, cordierite is added as a shell material to glass B (Example 3), the temperature coefficient τf of the resonant frequency of glass B can be changed from A positive value of 2.99 is adjusted towards zero. Taking core-shell molar ratio 98:2 (Example 3) as an example, the overall resonant frequency temperature coefficient can be adjusted to τf=-0.20 (20 ^o C~100 ^o C). In other words, through this design, the overall The temperature coefficient of the resonant frequency is reduced, and it can even approach τf=0, which is more in line with the low τf characteristic of 5G LTCC.

In summary, the low-dielectric materials provided by some embodiments of the present invention have the characteristics of low Dk, low Df, and low τf, so as to achieve low delay, low loss, and low temperature-affected applications, which are more in line with 5G LTCC Material requirements.

Although this disclosure has been disclosed in several preferred embodiments as described above, it is not intended to limit the disclosure. Anyone with ordinary knowledge in the relevant technical field can make any changes without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be subject to the scope of the attached patent application.

100: core-shell particles 101: The first ceramic 103: The second ceramic 200, 300: low dielectric materials 201: Mesh structure 301: Alumina particles

FIG. 1 is a schematic diagram of core-shell particles in some embodiments of the present disclosure. FIG. 2 is a schematic diagram of low dielectric materials in some embodiments of the present disclosure. FIG. 3 is a schematic diagram of low dielectric materials in some embodiments of the present disclosure.

101: The first ceramic

103: The second ceramic

200: low dielectric material

201: Mesh structure

Claims (22)

A method for forming a low-dielectric material includes: Providing a plurality of core-shell particles, the core of the core-shell particles has a first ceramic with a low melting point, and the shell layer of the core-shell particles has a second ceramic with a low melting point and a low dielectric constant; The core-shell particles are sintered to form a low-dielectric material, wherein the shell layers of the core-shell particles are connected to form a microcrystalline phase network structure. Such as the method for forming a low-dielectric material of claim 1, wherein the core first ceramic includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, and zinc oxide, The weight ratio of silicon oxide to magnesium oxide is 100:0 to 100:85, The weight ratio of silica to alumina is 100:20 to 100:150, The weight ratio of silicon oxide to calcium oxide is 100:2 to 100:20, The weight ratio of silicon oxide to boron oxide is 100:2 to 100:70, and The weight ratio of silicon oxide to zinc oxide is 100:2 to 100:70. Such as the method for forming a low-dielectric material of claim 1, wherein the core first ceramic includes silicon oxide, aluminum oxide, calcium oxide, and boron oxide, The weight ratio of silica to alumina is 100:15 to 100:25, The weight ratio of silicon oxide to calcium oxide is 100:10 to 100:25, and The weight ratio of silicon oxide to boron oxide is 100:30 to 100:50. Such as the method for forming a low-dielectric material of claim 1, wherein the second ceramic of the shell layer includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide, The weight ratio of silicon oxide to magnesium oxide is 100:15 to 100:40, The weight ratio of silica to alumina is 100:35 to 100:90, The weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, The weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, The weight ratio of silicon oxide to bismuth oxide is 100:2 to 100:15, The weight ratio of silicon oxide to titanium oxide is 100:0.2 to 100:25, and The weight ratio of silicon oxide to copper oxide is 100:0.2 to 100:15. Such as the method for forming a low-dielectric material of claim 1, wherein the second ceramic of the shell layer includes silicon oxide, aluminum oxide, calcium oxide, boron oxide, and lithium oxide, The weight ratio of silica to alumina is 100:90 to 100:110, The weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, The weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, and The weight ratio of silicon oxide to lithium oxide is 100:90 to 100:110. Such as the method for forming a low-dielectric material of claim 1, wherein the molar ratio of the first ceramic of the core to the second ceramic of the shell is 100:0.1 to 100:10. Such as the method for forming a low-dielectric material of claim 1, wherein the melting point of the first ceramic of the core is 700°C to 900°C, the melting point of the second ceramic of the shell layer is 760°C to 910°C, and the second ceramic of the shell layer The melting point of the core is greater than the melting point of the first ceramic. The method for forming a low-dielectric material according to claim 1, wherein the temperature for sintering the core-shell particles is 800°C to 900°C. Such as the method for forming a low-dielectric material of claim 1, wherein the dielectric constant of the second ceramic of the shell layer is less than 6. The method for forming a low-dielectric material according to claim 1, wherein the particle size of the core-shell particles is 0.3 μm to 3 μm. For example, the method for forming a low-dielectric material of claim 1, further comprising adding a plurality of alumina particles when sintering the core-shell particles, so that the low-dielectric material includes the alumina particles dispersed therein, wherein the core-shell particles are dispersed therein. The weight ratio of the particles to the alumina particles is 100:25 to 100:45, and the particle size of the alumina particles is 50 nm to 2 µm. The method for forming a low dielectric material according to claim 1, wherein the dielectric constant of the low dielectric material is 3 to 5. A low-dielectric material, including: The first ceramic with a low melting point is dispersed in the connected second ceramic with a low melting point and a low dielectric constant, and the second ceramic of the shell layer has a network structure of a microcrystalline phase. Such as the low dielectric material of claim 13, wherein the first ceramic includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, and zinc oxide, The weight ratio of silicon oxide to magnesium oxide is 100:0 to 100:85, The weight ratio of silica to alumina is 100:20 to 100:150, The weight ratio of silicon oxide to calcium oxide is 100:2 to 100:20, The weight ratio of silicon oxide to boron oxide is 100:2 to 100:70, and The weight ratio of silicon oxide to zinc oxide is 100:2 to 100:70. Such as the low dielectric material of claim 13, wherein the first ceramic includes silicon oxide, aluminum oxide, calcium oxide, and boron oxide, The weight ratio of silica to alumina is 100:15 to 100:25, The weight ratio of silicon oxide to calcium oxide is 100:10 to 100:25, and The weight ratio of silicon oxide to boron oxide is 100:30 to 100:50. Such as the low dielectric material of claim 13, wherein the second ceramic includes silicon oxide, magnesium oxide, aluminum oxide, calcium oxide, boron oxide, bismuth oxide, titanium oxide, and copper oxide, The weight ratio of silicon oxide to magnesium oxide is 100:15 to 100:40, The weight ratio of silica to alumina is 100:35 to 100:90, The weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, The weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, The weight ratio of silicon oxide to bismuth oxide is 100:2 to 100:15, The weight ratio of silicon oxide to titanium oxide is 100:0.2 to 100:25, and The weight ratio of silicon oxide to copper oxide is 100:0.2 to 100:15. Such as the low dielectric material of claim 13, wherein the second ceramic includes silicon oxide, aluminum oxide, calcium oxide, boron oxide, and lithium oxide, The weight ratio of silica to alumina is 100:90 to 100:110, The weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, The weight ratio of silicon oxide to boron oxide is 100:5 to 100:25, and The weight ratio of silicon oxide to lithium oxide is 100:90 to 100:110. Such as the low dielectric material of claim 13, wherein the molar ratio of the first ceramic to the second ceramic is 100:0.1 to 100:10. The low dielectric material according to claim 13, wherein the melting point of the first ceramic is 700°C to 900°C, the melting point of the second ceramic is 760°C to 910°C, and the melting point of the second ceramic is greater than the melting point of the first ceramic. Such as the low dielectric material of claim 13, wherein the dielectric constant of the second ceramic is less than 6. For example, the low-dielectric material of claim 13, further comprising a plurality of alumina particles dispersed therein, wherein the ratio between the total weight of the first ceramic and the second ceramic and the weight of the alumina particles is 100:25 to 100: 45, and the particle size of the alumina particles is 50 nm to 2 µm. For example, the low dielectric material of claim 13 has a dielectric constant of 3 to 5.

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