Black aluminum oxide ceramic prepared from copper-niobium-titanium sintering aid at low temperature and preparation method of black aluminum oxide ceramic

Abstract

The invention discloses black aluminum oxide ceramic prepared from a copper-niobium-titanium sintering aid at low temperature and a preparation method of the black aluminum oxide ceramic. The black aluminum oxide ceramic comprises the following components in percentage by mass: 88%-94% of aluminum oxide, 1.8%-3.5% of copper oxide, 0.5%-1% of titanium dioxide, 1%-2.5% of niobium pentoxide, 1.2%-3% of ferric oxide, 0.2%-1% of cobalt oxide, 0.3%-1.2% of nickel oxide and 1%-2.5% of manganese dioxide. The black aluminum oxide ceramic can be sintered at a relatively low temperature, and has a black appearance and a good shading property while keeping high insulativity, dielectric property and mechanical strength. The coloring agent in the formula has a good color fixing effect, and the problem of performance reduction caused by black pigment in a traditional ceramic formula is also avoided. The components of the sintering aid in the formula can generate eutectic reaction with aluminum oxide to form a eutectic phase, and a liquid phase is formed at high temperature, so that the sintering difficulty is further reduced. The purposes of low sintering temperature, simple sintering process and stable performance of the sintered black alumina ceramic are achieved.

Description

Technical Field

[0001] The present invention relates to the field of ceramic materials, and particularly to a black alumina ceramic prepared at low temperature with a copper-niobium-titanium series sintering aid and a preparation method thereof. Background Art

[0002] At present, due to its excellent insulation, high temperature resistance and mechanical strength, alumina ceramics are widely used in the fields of substrate manufacturing of power electronic devices and semiconductor integrated circuit packaging. However, traditional alumina ceramics are white or light-colored, which cannot meet the requirements for the black appearance and light sensitivity of ceramic substrates in these application scenarios. In contrast, black alumina ceramic products have excellent properties such as high temperature resistance, wear resistance, insulation, heat insulation, corrosion resistance, and light shielding, and thus are widely used in the fields of electronic component technology, semiconductor integrated circuit packaging, and power ceramic substrates. Therefore, the market demand for black alumina ceramics is also continuously expanding. The innovation of new materials and the application of new technologies provide more possibilities for the design and production of black ceramics, enabling black ceramics to not only maintain their advantages in traditional fields but also play new roles in design innovation. However, in the prior art, there are still problems such as too high sintering temperature and complex firing process for black alumina ceramics. At the same time, after adding coloring agents and sintering aid components, it is easy to cause a decline in ceramic properties, affecting the service life and stability of the substrate.

[0003] Therefore, it is necessary to develop a black alumina ceramic formula with a simple firing process, good mechanical properties, electrical properties and light shielding properties and a corresponding preparation method. Summary of the Invention

[0004] In view of the technical problems that the sintering temperature of black alumina ceramics is too high and the firing process is complex. The purpose of the present invention is to provide a black alumina ceramic prepared at low temperature with a copper-niobium-titanium series sintering aid that can be sintered at a lower temperature and maintain high insulation, dielectric and mechanical strength, and a preparation method thereof.

[0005] To achieve the above object, the present invention adopts the following specific technical solutions:

[0006] A black alumina ceramic prepared at low temperature with a copper-niobium-titanium series sintering aid, by mass fraction, includes: 88% - 94% of alumina, 1.8 - 3.5% of copper oxide, 0.5 - 1% of titanium dioxide, 1 - 2.5% of niobium pentoxide, 1.2 - 3% of iron(III) oxide, 0.2 - 1% of cobalt oxide, 0.3 - 1.2% of nickel oxide, 1 - 2.5% of manganese dioxide.

[0007] Further, the alumina is α-Al 2 O 3。

[0008] A preparation method of black alumina ceramics prepared at low temperature with a copper-niobium-titanium series sintering aid, comprising:

[0009] Step 1, weighing ceramic raw materials: Weigh α-Al 2 O 3 88% - 94% by mass fraction, take 1.8 - 3.5% of copper oxide, 0.5 - 1% of titanium dioxide, 1 - 2.5% of niobium pentoxide as the sintering aid, and take 1.2 - 3% of iron oxide, 0.2 - 1% of cobalt oxide, 0.3 - 1.2% of nickel oxide, 1 - 2.5% of manganese dioxide as the colorant;

[0010] Step 2, ball milling: Add the weighed ceramic raw materials to a ball milling tank, use ethanol as the solvent, and ball mill at a rotation speed of 300 r / min for 2 - 6 h to obtain a premix;

[0011] Step 3, granulation: Mix the premix with a binder solution and ball mill for 20 - 40 min, use a dry granulator for granulation, and then pass through a 60 - 200 mesh sieve for granulation to obtain ceramic granulated powder;

[0012] Step 4, pressing into shape: Place the ceramic granulated powder in a mold for pressing into shape to obtain a ceramic green body;

[0013] Step 5, sintering: Place the ceramic green body in a sintering furnace, heat it to 1150 - 1250 °C at a heating rate of 2 - 5 °C / min and sinter for 2 - 4 h to obtain black alumina ceramics.

[0014] Further, in step 2, the ethanol and the ceramic raw materials in the ball milled premix are configured according to a mass ratio of 0.8 - 1:1.

[0015] Further, in step 3, the binder solution is a solution configured by arabic gum and deionized water according to a mass ratio of 1:8 - 10.

[0016] Further, in step 3, the weight ratio of the binder solution to the ceramic raw materials is 5% - 10%.

[0017] Further, in step 4, the pressure of the press is controlled at 10 - 20 MPa during the pressing into shape process.

[0018] A preparation method of black alumina ceramics prepared at low temperature with a copper-niobium-titanium series sintering aid, comprising:

[0019] Step 1, mix and ball mill iron oxide, cobalt oxide, nickel oxide and manganese dioxide according to a mass ratio of (1.2 - 3%):(0.2 - 1%):(0.3 - 1.2%):(1 - 2.5%), dry it and sinter at 1150 °C for 2 h to obtain a black colorant;

[0020] Step 2: Weigh the ceramic raw materials by mass fraction: Take 5-8% of the previously obtained colorant, 88%-94% of alumina powder, 1.8-3.5% of copper oxide, 0.5-1% of titanium dioxide, and 1-2.5% of niobium pentoxide, mix and ball-mill them, and add ethanol to ball-mill for 2-6 h to obtain a premix;

[0021] Step 3: Mix and ball-mill the premix with the binder solution for 20-40 min, granulate using a dry granulator, and then pass through a 60-200 mesh sieve for granulation to obtain ceramic granulated powder;

[0022] Step 4: Place the ceramic granulated powder in a mold for pressing and forming, control to obtain a ceramic blank under a pressure of 10-20 MPa, and sinter at a heating rate of 2-5 °C / min to 1150-1250 °C for 2-4 h to obtain black alumina ceramic.

[0023] Further, in Step 1, iron(III) oxide, cobalt oxide, nickel oxide, and manganese dioxide are mixed and ball-milled according to a mass ratio of 3:0.5:1:2.5.

[0024] The present invention can achieve the following technical effects:

[0025] In the black alumina ceramic formula of the present invention, the colorant has a good color-fixing effect, and also avoids the problem of performance degradation caused by black pigments in traditional ceramic formulas. The components of the sintering aid in the formula can produce a eutectic reaction with alumina to form a eutectic phase, and form a liquid phase at high temperature, thereby further reducing the sintering difficulty.

[0026] The black alumina ceramic has a uniform black appearance and is suitable for applications in fields such as power ceramic substrates and semiconductor integrated circuit packaging; while maintaining high insulation, dielectric properties, and mechanical strength, the ceramic also has good light-shielding properties; through reasonable composition matching, the problem of performance degradation caused by black pigments in traditional ceramic formulas is avoided. The purpose of low sintering temperature, simple firing process, and stable performance of the fired black alumina ceramic is achieved. The purpose of low sintering temperature, simple firing process, and stable performance of the fired black alumina ceramic is achieved.

[0027] In terms of the preparation method, the sintering temperature is low and the firing process is simple, and it can be fired in air at 1150-1250 °C. It can be sintered at a lower temperature, and while maintaining high insulation, dielectric properties, and mechanical strength, the ceramic also presents a black appearance and has good light-shielding properties. Description of the Drawings

[0028] Figure 1 XRD pattern of the black alumina ceramic material prepared by the present invention;

[0029] Figure 2 SEM image of the black alumina ceramic material prepared by the present invention. Detailed implementation mode

[0030] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0031] A black alumina ceramic prepared at low temperature with a copper-niobium-titanium series sintering aid, by mass fraction, includes: 88% - 94% alumina, 1.8 - 3.5% copper oxide, 0.5 - 1% titanium dioxide, 1 - 2.5% niobium pentoxide, 1.2 - 3% iron(III) oxide, 0.2 - 1% cobalt oxide, 0.3 - 1.2% nickel oxide, 1 - 2.5% manganese dioxide.

[0032] A preparation method of a black alumina ceramic prepared at low temperature with a copper-niobium-titanium series sintering aid, includes:

[0033] Step 1, ceramic raw materials: Weigh α-Al 2 O 3 88% - 94%, 1.8 - 3.5% copper oxide, 0.5 - 1% titanium dioxide, 1 - 2.5% niobium pentoxide, 1.2 - 3% iron(III) oxide, 0.2 - 1% cobalt oxide, 0.3 - 1.2% nickel oxide, 1 - 2.5% manganese dioxide;

[0034] Among them, copper oxide, titanium dioxide and niobium pentoxide are taken as sintering aids, and iron(III) oxide, cobalt oxide, nickel oxide and manganese dioxide are taken as colorants;

[0035] Step 2, ball milling: Add the weighed ceramic raw materials into a ball milling tank, use ethanol as a solvent, and ball mill at a rotation speed of 300 r / min for 2 - 6 h to obtain a premix;

[0036] Step 3, granulation: Mix the premix with a binder solution and ball mill for 20 - 40 min, use a dry granulator for granulation, and then pass through a 60 - 200 mesh sieve for granulation to obtain ceramic granulated powder;

[0037] Step 4, pressing into shape: Place the ceramic granulated powder in a mold for pressing into shape to obtain a ceramic green body;

[0038] Step 5, sintering: Place the ceramic green body in a sintering furnace, heat it to 1150 - 1250 °C at a heating rate of 2 - 5 °C / min and sinter for 2 - 4 h to obtain a black alumina ceramic.

[0039] The above is the one-step method, and there is also a two-step method as follows:

[0040] A preparation method of a black alumina ceramic prepared at low temperature with a copper-niobium-titanium series sintering aid, includes:

[0041] Step 1: Mix iron(III) oxide, cobalt oxide, nickel oxide, and manganese dioxide in a mass ratio of (1.2 - 3%):(0.2 - 1%):(0.3 - 1.2%):(1 - 2.5%), grind them in a ball mill, dry them, and sinter them at 1150 °C for 2 h to obtain a black colorant.

[0042] Step 2: Weigh the ceramic raw materials by mass fraction: Take 5 - 8% of the previously obtained colorant, 88% - 94% of alumina powder, 1.8 - 3.5% of copper oxide, 0.5 - 1% of titanium dioxide, and 1 - 2.5% of niobium pentoxide, mix and grind them in a ball mill, and add ethanol to grind for 2 - 6 h to obtain a premix.

[0043] Step 3: Mix the premix with a binder solution in a ball mill for 20 - 40 min, granulate it using a dry granulator, and then pass it through a 60 - 200 mesh sieve to obtain ceramic granulated powder.

[0044] Step 4: Place the ceramic granulated powder in a mold for pressing and forming, control the pressure at 10 - 20 MPa to obtain a ceramic blank, and sinter it at a heating rate of 2 - 5 °C / min to 1150 - 1250 °C for 2 - 4 h to obtain black alumina ceramic.

[0045] Preferably, in Step 1, mix iron(III) oxide, cobalt oxide, nickel oxide, and manganese dioxide in a mass ratio of 3:0.5:1:2.5 and grind them in a ball mill.

[0046] Example 1:

[0047] Weigh the ceramic raw materials by mass fraction: Weigh 88% of alumina powder, 2% of copper oxide, 0.5% of titanium dioxide, 2% of niobium pentoxide, 3% of iron(III) oxide, 0.8% of cobalt oxide, 1.2% of nickel oxide, and 2.5% of manganese dioxide, and put them into a ball mill tank. Add 100 mL of ethanol solution and grind at a speed of 300 r / min for 6 h to obtain a premix. Then add an arabic gum binder solution with a mass ratio of 80% to the ceramic powder and grind for 30 min. Granulate it using a dry granulator, sieve the ceramic granulated powder with a mesh size between 60 - 200, place the ceramic granulated powder in a mold for pressing and forming, control the pressure at 20 MPa to obtain a ceramic blank. Transfer the ceramic blank to a sintering furnace and keep it at 1180 °C for 2 h to obtain a black alumina ceramic with high density and excellent insulation.

[0048] Example 2:

[0049] Weigh the ceramic raw materials by mass fraction: Use 92% alumina content, take 1% copper oxide, 0.5% titanium dioxide and 1% niobium pentoxide as sintering aids, and take 2% iron(III) oxide, 0.5% cobalt oxide, 1% nickel oxide and 2% manganese dioxide as colorants. Then add an appropriate amount of ethanol and ball mill for 2 h to obtain a premix. Then add an arabic gum binder solution with a mass ratio of 80% to the ceramic powder and ball mill for 20 min. Use a dry granulator for granulation, and use a sieve to take the granulated powder with a mesh size between 60 and 200 meshes. Place the ceramic granulated powder in a mold for pressing and forming, and control to obtain a ceramic blank under a pressure of 18 MPa. Sinter at 1230 °C for 2.5 h to obtain a black alumina ceramic with excellent high insulation, dielectric properties and mechanical properties.

[0050] Example 3:

[0051] Mix iron(III) oxide, cobalt oxide, nickel oxide and manganese dioxide according to a mass ratio of 3:0.5:1:2.5, ball mill, dry, and sinter at 1150 °C for 2 h to obtain a black colorant. Weigh the ceramic raw materials by mass fraction: Take 7% of the previously obtained colorant, mix and ball mill with 88% alumina powder, 2% copper oxide, 1% titanium dioxide and 2% niobium pentoxide, add ethanol and ball mill for 4 h to obtain a premix. Then add an arabic gum binder solution with a mass ratio of 80% to the ceramic powder and ball mill for 40 min. Use a dry granulator for granulation to obtain ceramic granulated powder. Place the ceramic granulated powder in a mold for pressing and forming, and control to obtain a ceramic blank under a pressure of 15 MPa. Raise the temperature to 1200 °C at a heating rate of 4 °C / min and sinter for 2 h to obtain a black alumina ceramic prepared by a two-step method.

[0052] Table 1 Black alumina ceramics prepared in Examples 1-3

[0053]

[0054] Table 2 Black alumina ceramics prepared in Examples 1-3

[0055] Project Example 1 Example 2 Example 3 <![CDATA[Density (g / cm 3 )]]> 3.60 3.67 3.63 Water Absorption Rate (%) 0 0 0 Vickers Hardness (GPa) 11.0 11.7 11.2 Flexural Strength (MPa) 310 320 310 Volume Resistivity (Ω·cm) <![CDATA[4.85×10 11 > <![CDATA[8.91×10 11 > <![CDATA[6.16×10 11 > Dielectric Constant 9.6 9.2 9.5

[0056] As can be seen from Table 1 and Table 2, when using the preparation methods of Examples 1-3 of this patent, while maintaining high insulation, dielectric properties and mechanical strength, the ceramics also present a black appearance and have good light-shielding properties. This is because the colorant and sintering aid systems in the preparation method of this patent have a reasonable composition ratio. The colorant formula has a good color-fixing effect and also avoids the problem of performance degradation caused by black pigments in traditional ceramic formulas. The volume resistivity of the black alumina ceramic can reach ≥10 11 Ω·cm, and the dielectric constant is 9-10. In addition, the black alumina ceramic formula provided by this patent is not limited to being prepared by one-step sintering. Two-step sintering can also be used. First, sinter the colorant, and then co-sinter with alumina and sintering aids.Figure 1 It can be seen that niobium pentoxide and titanium dioxide in the sintering aid can form a eutectic phase by eutectic reaction with alumina, and copper oxide can form a liquid phase at high temperature to further reduce the sintering difficulty. From Figure 2 It can be observed that obvious "burning necks" are formed between alumina powder particles, achieving the purpose of low sintering temperature and simple firing process. Densification sintering of black alumina ceramics can be realized at 1150-1250 °C in air.

[0057] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0058] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0059] The above specific implementation manners of the present invention do not constitute a limitation to the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A black alumina ceramic prepared at low temperature using a copper-niobium-titanium series sintering aid, characterized in that: Calculated by mass fraction, it includes: 88% to 94% aluminum oxide, 1.8% to 3.5% copper oxide, 0.5% to 1% titanium dioxide, 1% to 2.5% niobium pentoxide, 1.2% to 3% iron oxide, 0.2% to 1% cobalt oxide, 0.3% to 1.2% nickel oxide, and 1% to 2.5% manganese dioxide.

2. The black alumina ceramic prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 1, characterized in that: The aluminum oxide is α-Al2O3.

3. The method for preparing black alumina ceramics prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 2, characterized in that: include: Step 1, weighing ceramic raw materials: weighing α-Al2O3 88% to 94% by mass, taking 1.8 to 3.5% of copper oxide, 0.5 to 1% of titanium dioxide, and 1 to 2.5% of niobium pentoxide as sintering aids, and taking 1.2 to 3% of ferric oxide, 0.2 to 1% of cobalt oxide, 0.3 to 1.2% of nickel oxide, and 1 to 2.5% of manganese dioxide as colorants; Step 2, ball milling: adding the weighed ceramic raw materials into a ball milling jar, using ethanol as a solvent, and ball milling at a speed of 300 r / min for 2 to 6 hours to obtain a premix; Step 3, granulation: the premix and the binder solution are mixed and ball-milled for 20 to 40 minutes, granulated by a dry granulator, and then granulated through a 60 to 200 mesh sieve to obtain ceramic granulated powder; Step 4: Pressing and molding: placing the ceramic granulated powder in a mold for pressing and molding to obtain a ceramic body; Step 5: Sintering: Place the ceramic body in a sintering furnace, raise the temperature to 1150-1250° C. at a heating rate of 2-5° C. / min, and sinter for 2-4 hours to obtain black alumina ceramics.

4. The method for preparing black alumina ceramics prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 3, characterized in that: In the step 2, the ethanol and the ceramic raw material in the ball mill premix are configured in a mass ratio of 0.8 to 1:

1.

5. The method for preparing black alumina ceramics prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 3, characterized in that: The binder solution in step three is a solution prepared by mixing gum arabic with deionized water in a mass ratio of 1:8 to 10.

6. The method for preparing black alumina ceramics prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 3, characterized in that: In the step three, the weight ratio of the binder solution to the ceramic raw material is 5% to 10%.

7. The method for preparing black alumina ceramics prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 3, characterized in that: During the pressing process in step 4, the pressure of the press is controlled at 10-20 MPa.

8. The method for preparing black alumina ceramics prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 2, characterized in that: include: Step 1, mixing ferric oxide, cobalt oxide, nickel oxide and manganese dioxide in a mass ratio of (1.2-3%): (0.2-1%): (0.3-1.2%): (1-2.5%), ball milling, drying and sintering at 1150° C. for 2 hours to obtain a black colorant; Step 2, weigh ceramic raw materials according to mass fraction: 5-8% of the pre-obtained colorant, 88%-94% of aluminum oxide powder, 1.8-3.5% of copper oxide, 0.5-1% of titanium dioxide and 1-2.5% of niobium pentoxide are mixed and ball-milled, and ethanol is added and ball-milled for 2-6 hours to form a premix; Step 3: Mix the premix and the binder solution and ball-mill for 20 to 40 minutes, granulate them using a dry granulator, and then granulate them through a 60 to 200 mesh sieve to obtain ceramic granulated powder; Step 4: Place the ceramic granulated powder in a mold for compression molding, control the pressure at 10-20 MPa to obtain a ceramic blank, increase the temperature to 1150-1250° C. at a heating rate of 2-5° C. / min, and sinter for 2-4 hours to obtain black alumina ceramics.

9. The method for preparing black alumina ceramics prepared at low temperature using a copper-niobium-titanium series sintering aid as claimed in claim 8, characterized in that: In step 1, ferric oxide, cobalt oxide, nickel oxide and manganese dioxide are mixed and ball-milled in a mass ratio of 3:0.5:1:2.5.

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