TWI766494B - 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 method of forming the same

The present disclosure pertains to low-k materials and methods of forming the same.

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 vigorous development of domestic high-frequency industries such as millimeter-wave substrates, materials/components, and module integration and other related markets. For 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 should be developed to achieve small 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 particle has a first ceramic with a low melting point, and the shell layer of the core-shell particle has a low melting point and a low melting point. A second ceramic with a 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.

In some embodiments, the first ceramic of the core comprises 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 wherein the weight ratio of silicon oxide to zinc oxide is from 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, wherein the ratio of silicon oxide to calcium oxide is 100:15 to 100:25. The weight ratio is 100:10 to 100:25, and wherein 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, wherein the weight ratio of silica to alumina is 100:35 to 100:90, wherein the weight ratio of silica to calcium oxide is 100:0.2 to 100:10, wherein the weight of silica 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, wherein the weight ratio of silicon oxide to titanium oxide is 100:0.2 to 100:25, and wherein the silicon oxide 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, wherein the 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 to 100:10.

In some embodiments, the first ceramic of the core has a melting point of 700°C to 900°C, the second ceramic of the shell has a melting point of 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 at which the core-shell particles are sintered 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, so that the low-dielectric material including alumina particles are dispersed therein, wherein the weight ratio of the core-shell particles to the alumina particles is 100:25 to 100:45 with alumina particles ranging in size from 50 nm to 2 µm.

In some embodiments, the low dielectric material has a dielectric constant of 3 to 5.

An embodiment of the present disclosure provides a low-dielectric material, comprising: 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 mesh 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, wherein the 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 wherein the weight ratio of silicon oxide to zinc oxide is from 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 is 100:15 to 100:25. is 100:10 to 100:25, and wherein 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, wherein the weight ratio of silicon oxide to aluminum oxide is 100:35 to 100:90, wherein the weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, and the weight ratio of silicon oxide to boron oxide is 100 :5 to 100:25, wherein the weight ratio of silicon oxide to bismuth oxide is 100:2 to 100:15, wherein the weight ratio of silicon oxide to titanium oxide is 100:0.2 to 100:25, and wherein the weight ratio of silicon oxide to 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, wherein silicon oxide and calcium oxide 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 from 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.

The dielectric constant of the second ceramic is less than 6 in some embodiments.

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 low dielectric material has a dielectric constant of 3 to 5.

Some embodiments of the present disclosure provide a method for forming a low dielectric material, including 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 layer 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 first ceramic 101 of the core 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, 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 ratio of magnesium oxide is too low, the melting point is too high, and sintering cannot be formed. If the ratio 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 silicon oxide to aluminum oxide is 100:20 to 100:150, such as 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 ratio of alumina is too low, dielectric loss is likely to occur. When the ratio 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 100:2 to 100:20, for example, 100:3 to 100:18, 100:5 to 100:15, or 100:6 to 100:12, but not limited thereto. 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 is too low, and it is easy to 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 ratio of boron oxide is too low, the melting point is too high, and sintering cannot be formed. 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 ratio of zinc oxide is too low, the melting point is too high, and sintering cannot be formed. 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 cooperate with the LTCC process, it also cannot be matched with the melting point of the second ceramic to form a core-shell particle structure.

In one embodiment, the first ceramic 101 of the core 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, for example, 100:15 to 100:20, or 100:20 to 100:25, etc., but not limited thereto. If the ratio of alumina is too low, dielectric loss is likely to occur. If the ratio 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, such as 100:10 to 100:15, 100:15 to 100:20, 100:20 to 100:25, or 100:12 to 100:10: 22, etc., but not limited thereto. 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 is too low, and it is easy to melt and cannot be matched with the LTCC process. The weight ratio of silicon oxide to boron oxide is 100:30 to 100:50, such as 100:30 to 100:40, 100:40 to 100:50, 100:32 to 100:48, or 100:35 to 100: 45, etc., but not limited to this. If the ratio of boron oxide is too low, the melting point is too high, and sintering cannot be formed. 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 cooperate with the LTCC process, it also 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, such as about 100:20 to 100:40, 100:15 to 100:35, 100:18 to 100:38, or 100:20 to 100:40: 35, etc., but not limited thereto. When the ratio of magnesium oxide is too low or too high, a cordierite crystal phase cannot be formed. The weight ratio of silicon oxide to aluminum oxide is 100:35 to 100:90, such as about 100:35 to 100:85, 100:40 to 100:80, 100:35 to 100:75, or 100:30 to 100:00: 70, etc., but not limited to this. If the ratio 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, such as about 100:0.5 to 100:10, 100:1 to 100:10, 100:2 to 100:10, or 100:0.5 to 100:10: 5, etc., but not limited to this. If the proportion of calcium oxide is too low, the fluxing effect is not good and the sintering temperature is too high. When the ratio of calcium oxide is too high, the 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. When the ratio 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 ratio of bismuth oxide is too low, the fluxing effect is not good and the sintering temperature is high. If the ratio 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 ratio of titanium oxide is too low, the crystallinity will be poor and phase formation will be difficult. When the ratio 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, for example, about 100:0.5 to 100:15, 100:1 to 100:10, or 100:2 to 100:12, but not limited thereto. If the proportion of copper oxide is too low, the fluxing effect is not good and the sintering temperature is too high. When the ratio of copper oxide is too high, a 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 ratio of alumina is too low or too high, a 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, etc., but not limited thereto. If the proportion of calcium oxide is too low, the fluxing effect is not good and the sintering temperature is too high. If the ratio of calcium oxide is too high, a 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 ratio 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 ratio of lithium oxide is too low or too high, the eucryptite crystal phase cannot be formed.

In one 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, such as 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 thereto. If the proportion of the second ceramic 103 is too low or the thickness of the shell layer is too thin, the dielectric constant and the dielectric loss will be high. If the ratio 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, but the added amount of the second ceramic material will be wasted.

In one embodiment, the melting point of the first ceramic 101 of the core is 700°C to 900°C, such as 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, etc., but not limited thereto. If the melting points of the two ceramic materials are too low or too high, the subsequent process temperature of the materials 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 one embodiment, the dielectric constant of the second ceramic 103 of the shell layer is less than 6, such as about 1, 2, 3, 4, or 5, but 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, for example, 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 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 for 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 various oxide sources (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, which is then heated to form a gel, which is dried and ground to form a powder. The powder may then be further heat treated to form core-shell particles 100 . It is worth noting that those with ordinary knowledge in the art can form the core-shell particles 100 by appropriate processes, and are not limited to the above-mentioned sol-gel method.

The core-shell particles are then sintered to form a low dielectric material 200, as shown in FIG. 2 . The second ceramics 103 of the shell layer of the core-shell particles 100 will be connected to form a network structure 201 of microcrystalline phase, and the first ceramics 101 will be dispersed in the connected second ceramics 103 . In one embodiment, the temperature for 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 not limited thereto. If the sintering temperature is too low, there will be many defects in the material, and the dielectric constant and dielectric loss will be high. If the sintering temperature is too high, the material will melt and cannot be formed.

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 including the alumina particles 301 is dispersed therein, as shown in FIG. 3 . In some embodiments, the weight ratio of core-shell particles 100 to alumina particles 301 is 100:25 to 100:45, eg, 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 . When the ratio of the alumina particles 301 is too high, the dielectric constant increases. In one embodiment, the particle size of the alumina particles 301 is 50 nm to 2 µm, such as 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. When the particle size of the alumina particles 301 is too large, the network structure is broken and the dielectric constant increases.

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, but not limited thereto.

In order to make the above-mentioned content and other objects, features, and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are given below, and are described in detail as follows in conjunction with the accompanying drawings: [ Embodiment ]

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), dissolved in absolute ethanol, and then put into The filler glass A (containing the main components MgO about 50 weight parts, Al ₂ O ₃ about 38.6 weight parts, SiO ₂ about 100 weight parts, average molecular weight about 57.4) was stirred 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 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) were added to the mixture of absolute ethanol and deionized water, and stirred well , and adjust the pH value to 9.23 with ammonia water to obtain liquid B. A sol is obtained by mixing liquid A and B and stirring uniformly.

Next, put the sol into an oven at 40°C and let it stand for sol-gelation to obtain a gel, and then place the gel in an environment of 80°C to dry, take out and grind it into powder, and place it at 250°C to keep the temperature After 3 hours, the temperature was raised to 750°C for 2 hours. After cooling, it was ground into powder to obtain a LTCC powder with a core-shell structure, the core (glass A) and 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 billet with a diameter of 11 mm under the condition of a pressure of 40 kg/m ² , and hold the temperature at 850 °C for 2 hours, so that the shell layers of the core-shell particles are connected to form a network structure of microcrystalline phase. The density of the above product was 2.71 g/cm ³ , the dielectric constant Dk was 4.72 (1 GHz), and the dielectric loss Df was 3.4×10 ⁻⁴ (1 GHz). 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), dissolved in absolute ethanol, and then put into The filler glass A (containing the main components MgO about 50 weight parts, Al ₂ O ₃ about 38.6 weight parts, SiO ₂ about 100 weight parts, and the average molecular weight about 57.4) was stirred 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 value to 9.23 with ammonia water to obtain liquid B. A sol is obtained by mixing liquid A and B and stirring uniformly.

Next, put the sol into an oven at 40°C and let it stand for sol-gelation to obtain a gel, and then place the gel in an environment of 80°C to dry, take out and grind it into powder, and place it at 250°C to keep the temperature After 3 hours, the temperature was raised to 750°C for 2 hours. After cooling, it was ground into powder to obtain a LTCC powder with a core-shell structure, the core (glass A) and 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 billet with a diameter of 11 mm under the condition of a pressure of 40 kg/m ² , and hold the temperature at 850 °C for 2 hours, so that the shell layers of the core-shell particles are connected to form a network structure of microcrystalline phase. The density of the above product was 2.72 g/cm ³ , the dielectric constant Dk was 5.13 (1 GHz), and the dielectric loss Df was 5.4×10 ⁻⁴ (1 GHz). 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, 1.55 g, 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), dissolved in absolute ethanol, and then put into The filler glass B (containing about 47.2 weight points of main components B ₂ O ₃ , about 105.5 weight points of Al ₂ O ₃ , about 100 weight points of SiO ₂ , and an average molecular weight of about 72.5) was stirred until uniform to obtain liquid A. The modifiers 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 value to 9.23 with ammonia water to obtain liquid B. A sol is obtained by mixing liquid A and B and stirring uniformly.

Next, put the sol into an oven at 40°C and let it stand for sol-gelation to obtain a gel, and then place the gel in an environment of 80°C to dry, take out and grind it into powder, and place it at 250°C to keep the temperature After 3 hours, the temperature was raised to 750°C for 2 hours. After cooling, it was ground into powder to obtain a LTCC powder with a core-shell structure. Its core (glass B) and 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 billet with a diameter of 11 mm under the condition of a pressure of 40 kg/m ² , and hold the temperature at 850 °C for 2 hours, so that the shell layers of the core-shell particles are connected to form a network structure of microcrystalline phase. 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 resonant frequency temperature coefficient 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 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), dissolved in absolute ethanol, and then put into The filler glass C (containing the main components B ₂ O ₃ about 37.21 weight points, Al ₂ O ₃ about 21.39 weight points, CaO about 19.01 weight points, SiO ₂ about 100 weight points, and average molecular weight about 65.7), stir until Homogeneous to obtain Liquid A. 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 value to 9.23 with ammonia water to obtain liquid B. A sol is obtained by mixing liquid A and B and stirring uniformly.

Next, put the sol into an oven at 40°C and let it stand for sol-gelation to obtain a gel, and then place the gel in an environment of 80°C to dry, take out and grind it into powder, and place it at 250°C to keep the temperature After 3 hours, the temperature was raised to 750 °C for 2 hours. After cooling, it was ground into powder to obtain a LTCC powder with a core-shell structure. Its core (glass C) and 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 billet with a diameter of 11 mm under the condition of a pressure of 40 kg/m ² , and hold the temperature at 850 °C for 2 hours, so that the shell layers of the core-shell particles are connected to form a network structure of microcrystalline phase. The above product has a density of 2.37 g/cm ³ , a dielectric constant Dk of 4.7 (1 GHz), and a dielectric loss Df of 1.5*10 ^-3 (1 GHz). 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 billet 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 was 3.13 g/cm ³ , the dielectric constant Dk was 5.79 (1 GHz), and the dielectric loss Df was 1.3×10 ⁻³ (1 GHz). 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 billet 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 resonant frequency temperature coefficient 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 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 billet 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 was 2.35 g/cm ³ , the dielectric constant Dk was 4.91 (1 GHz), and the dielectric loss Df was 1.5×10 ⁻³ (1 GHz). 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 resonant frequency temperature coefficient τf of the products of Examples 1-4 and Comparative Examples 1-3 were compared with Table 1 below.

Table 1 Core Shell Molar Ratio (ingredients) Product density (g/cm ³ ) Dielectric constant Dk Dielectric loss Df Resonant 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) --

It can be seen from the examples and comparative examples shown in Table 1 that in terms of dielectric constant, the dielectric constant of the core-shell particles after sintering 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 much lower than that of using only the core material, or at least maintained at the same level (Examples 1-4 and Comparative Examples 1-3).

Please continue to refer to Table 1, in terms of resonant frequency temperature coefficient, glass B (Comparative Example 2) has a positive resonant frequency temperature coefficient τf=2.99 (20 ^o C ~ 100 ^o C), cordierite has a negative resonant frequency temperature coefficient τf =-12.61 (20 ^o C ~ 100 ^o C), through the core-shell structure design of the present invention, adding cordierite as a shell material to glass B (Example 3), the resonant frequency temperature coefficient τf of glass B can be made by A positive value of 2.99 adjusts to approach 0. Taking the core-shell molar ratio of 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 characteristics that 5G LTCC should have.

To sum up, 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 applications with low delay, low loss, and little influence by temperature, and are more suitable for 5G LTCC material requirements.

Although the present disclosure has been disclosed above with several preferred embodiments, it is not intended to limit the present disclosure. Anyone with ordinary knowledge in the technical field can make any changes without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the appended patent application.

100: core-shell particles 101: First Ceramics 103: Second Ceramic 200, 300: low dielectric materials 201: Mesh 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 a low-k material in some embodiments of the present disclosure. FIG. 3 is a schematic diagram of a low-k material in some embodiments of the present disclosure.

101: First Ceramics

103: Second Ceramic

200: Low Dielectric Materials

201: Mesh

Claims (21)

A method for forming a low dielectric material, comprising: providing a plurality of core-shell particles, the cores of the core-shell particles have a first ceramic with a low melting point, and the shell layers of the core-shell particles have a low melting point and a low dielectric constant the second ceramic; sintering the core-shell particles to form a low-dielectric material, wherein the shell layers of the core-shell particles are connected to form a microcrystalline phase network structure. The method for forming a low dielectric material according to claim 1, wherein the first ceramic of the core comprises 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, in which the weight ratio of silicon oxide to aluminum oxide is 100:20 to 100:150, and the weight ratio of silicon oxide to calcium oxide is 100:2 to 100:20, in which the weight ratio of silicon oxide to boron oxide is 100:2 to 100:20. The weight ratio is 100:2 to 100:70, and wherein the weight ratio of silicon oxide to zinc oxide is 100:2 to 100:70. The method for forming a low dielectric material according to claim 1, wherein the first ceramic of the core comprises 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 , wherein 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. The method for forming a low dielectric material according to claim 1, wherein the second ceramic of the shell layer comprises 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 silicon oxide to aluminum oxide is 100:35 to 100:90, and 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 wherein the weight ratio of silicon oxide to copper oxide is 100:0.2 to 100:15. The method for forming a low dielectric material according to claim 1, wherein the second ceramic of the shell layer comprises 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, 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, and where the weight of silicon oxide to lithium oxide The ratio is 100:90 to 100:110. The method for forming a low dielectric material according to 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. The method for forming a low dielectric material according to 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 has a melting point of 760°C to 910°C. The melting point is greater than the melting point of the core 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. The method for forming a low dielectric material according to 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 microns to 3 microns. The method for forming a low-dielectric material according to claim 1, further comprising adding a plurality of alumina particles when sintering the core-shell particles, so that the low-dielectric material including the alumina particles are 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, comprising: 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 network structure; and a plurality of Alumina particles are dispersed in the low dielectric material, and the particle diameters of the alumina particles are 50 nm to 2 μm, wherein the difference between the total weight of the first ceramic and the second ceramic and the weight of the alumina particles is The ratio is 100:25 to 100:45. The low dielectric material of claim 13, wherein the first ceramic comprises 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. The low dielectric material of claim 13, wherein the first ceramic comprises 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, wherein silicon oxide and The weight ratio of calcium oxide is 100:10 to 100:25, and wherein the weight ratio of silicon oxide to boron oxide is 100:30 to 100:50. The low dielectric material of claim 13, wherein the second ceramic comprises 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, wherein the weight ratio of silicon oxide to aluminum oxide is 100:35 to 100:90, wherein the weight ratio of silicon oxide to calcium oxide is 100:0.2 to 100:10, wherein the weight ratio of silicon oxide to boron oxide The weight ratio of silicon oxide to bismuth oxide 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 wherein The weight ratio of silicon oxide to copper oxide is 100:0.2 to 100:15. The low dielectric material of claim 13, wherein the second ceramic comprises 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, wherein The weight ratio of silicon oxide to calcium oxide is from 100:0.2 to 100:10, wherein the weight ratio of silicon oxide to boron oxide is from 100:5 to 100:25, and the weight ratio of silicon oxide to lithium oxide is from 100:90 to 100:90. 100:110. 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 of 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 that of the first ceramic. The low dielectric material of claim 13, wherein the dielectric constant of the second ceramic is less than 6. The low dielectric material of claim 13 has a dielectric constant of 3 to 5.

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