WO2016145649A1

WO2016145649A1 - A black alumina ceramic powder, a black alumina ceramic body made of it and a process for producing the black alumina ceramic body

Info

Publication number: WO2016145649A1
Application number: PCT/CN2015/074569
Authority: WO
Inventors: Xuan YU; Wangyang QIN; Guangchao Xie; Bo Chen; Lufang JIA; Ying Qian
Original assignee: Hysol Huawei Electronics Co Ltd
Current assignee: Hysol Huawei Electronics Co Ltd
Priority date: 2015-03-19
Filing date: 2015-03-19
Publication date: 2016-09-22
Anticipated expiration: 2017-09-19
Also published as: CN107406328A

Abstract

A black alumina ceramic powder and processes for producing a black alumina ceramic body. The powder comprises Al ₂O ₃; a pigment composed of Fe ₂O ₃, NiO, MnO ₂ and Co ₂O ₃; and an additive selected from the group consisting of SiO ₂, TiO ₂ and La ₂O ₃ and combination thereof.

Description

A black alumina ceramic powder, a black alumina ceramic body made of it and a process for producing the black alumina ceramic body

Technical Field

The present invention relates to an alumina ceramic powder, a black alumina ceramic body made of it and a process for producing the black alumina ceramic body.

Background

Alumina (Al₂O₃) ceramics can be used as substrate and packaging materials for hybrid integrated circuits (HIC) and multi chip modules (MCM) because it has fine electrical and mechanical properties and high chemical stability. Because some electronic components cannot be exposed to light, a type of black Al₂O₃ ceramic has been developed that has additional advantages over general Al₂O₃ ceramics, such as lower sintering temperatures. It serves as a promising packaging material with ideal performance in the aspects of reliability, thermostabilization and hermetization.

With the rapid development of integrated circuit industry, electronic components have a tendency to be thinner, shorter and of higher performance, integrated circuit also has a tendency to be of higher integration, high-frequency, much higher I/O pin count direction. Furthermore, the packaging materials, especially the substrate material, should meet the requirements of the components in the aspects of the electrical properties, physical properties, chemical properties.

To achieve a black alumina ceramic sintered at a low temperature, MgO, SiO₂, CaO and the like are generally added as additives. However, the addition of such additives will result in low density of the obtained ceramic and thus decrease its property.

CN 101483417A discloses a black alumina ceramic, which is sintered at a low temperature of 1310-1330℃. However, the black alumina ceramic comprises a Cr-containing component, which is harmful to the worker’s health and environment. Furthermore, the properties of the black alumina ceramic are not disclosed in detail.

Therefore, there is still a need to a novel black alumina ceramic, which has excellent electrical properties, physical properties and chemical properties.

Summary of the invention

The object of the invention is to provide a black alumina ceramic powder, and a black alumina ceramic body made of it, which is sintered at low temperature and friendly to the environment, and has high bulk density, excellent electrical properties, physical properties and chemical properties.

.

In one aspect, the invention provides a black alumina ceramic powder, which comprises:

i) Al₂O₃；

ii) a pigment composed of Fe₂O₃, NiO, MnO₂ and Co₂O₃； and

iii) an additive selected from the group consisting of SiO₂, TiO₂ and La₂O₃ and combination thereof.

In a further aspect, the invention provides a process for producing the black alumina ceramic powder according to the invention, comprising the following steps:

1) weighing and mixing Fe₂O₃, NiO, MnO₂ and Co₂O₃.

2) firing the mixture at 1050℃～1250℃ for 1～4h and cooling the dried material to obtain a black pigment.

3) weighing and mixing Al₂O₃, the black pigment, SiO₂, TiO₂ and La₂O₃ to obtain a black alumina ceramic powder.

In a further aspect, the invention provides a process for producing a black alumina ceramic body, comprising the following steps:

1) weighing the black alumina ceramic powder according to the invention； adding a solvent, a dispersing agent, a binder and a plasticizer； milling； and tape casting after vacuuming to form a green body,

2) sintering the green body at 1250-1350℃ for 1～4 hours to produce the black alumina ceramic body.

Yet in a further aspect, the invention provides process for producing a black alumina ceramic body, comprising the following steps:

1) pelletizing the black alumina ceramic powder according to the invention with a binder to form a green body, and

2) sintering the green body at 1250-1350℃ for 1-4 hours to produce the black alumina ceramic body.

The black alumina ceramic powder or body according to the invention has excellent properties, such as high dielectric property, high volume resistivity, high mechanical strength； and can be sintered at a low temperature. Furthermore, different from the existing black alumina ceramic powder, the process for producing the black alumina ceramic powder or body according to the invention does not use any Cr-containing component, and therefore is friendly to the worker’s heather and the environment. Therefore, the black alumina ceramic powder or body according to the invention is suitable for industrial application, especially integrated circuit industry.

Detailed description of the invention

It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

In the context of the present invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.

As used herein, the singular forms “a” , “an” and “the” include both singular and plural referents unless the context clearly dictates otherwise.

The terms “comprising” , “comprises” and “comprised of” as used herein are synonymous with “including” , “includes” or “containing” , “contains” , and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.

The recitation of numerical end points includes all numbers and fractions subsumed within the respective ranges, as well as the recited end points.

When an amount, a concentration or other values or parameters is/are expressed in form of a range, a preferable range, or a preferable upper limit value and a preferable lower limit value, it should be understood as that any ranges obtained by combining any upper limit or preferable value with any lower limit or preferable value are specifically disclosed, without considering whether the obtained ranges are clearly mentioned in the context.

All references cited in the present specification are hereby incorporated by reference in their entirety.

Unless otherwise defined, all terms used in the disclosure of the invention, including technical and scientific terms, have the meaning as commonly understood by one of the ordinary skill in the art to which this invention belongs to. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

i) Al₂O₃；

ii) a pigment composed of Fe₂O₃, NiO, MnO₂ and Co₂O₃； and

The black alumina ceramic powder according to the invention does not comprise any Cr-containing component. It is well known Cr element presented during the experiment and producing process is harmful to the worker’s health and environment.

Alumina, expressed as Al₂O₃, used in the invention may be any alumina that can be available in the market, as long as its purity is not very low. For example, Al₂O₃ of Cp grade (Chemically Pure) or AR grade (Analytical Reagent) is preferably used in the invention. For the purpose of being easily mixed with other components, the alumina in the form of powder is preferred in the invention. Furthermore, alpha-alumina is more preferably used in the invention.

According to the invention, the pigment is composed of Fe₂O₃, NiO, MnO₂ and Co₂O₃. As a component of the pigment, any of Fe₂O₃, NiO, MnO₂ or Co₂O₃ generally used in the field of ceramic can be used in the invention, as long as its purity is not very low. For example, Fe₂O₃, NiO, MnO₂ or Co₂O₃ of CP or AR grade is preferably used in the invention. For the purpose of being easily mixed with other components, the components Fe₂O₃, NiO, MnO₂ and Co₂O₃ in the form of powder are also preferred in the invention.

According to the invention, the additive is selected from the group consisting of SiO₂, TiO₂ and La₂O₃ and combination thereof. In one embodiment, a combination of SiO₂, TiO₂ and La₂O₃ are specifically used. SiO₂, TiO₂ and La₂O₃ used in the invention may be those generally used for producing the black alumina ceramic. For example, SiO₂, TiO₂ and La₂O₃ of CP or AR grade are preferred in the invention. For the purpose of being easily mixed with other components, the components SiO₂, TiO₂ and La₂O₃ in the form of powder are preferably used in the invention.

In various embodiments, the black alumina ceramic powder comprises by weight of i) 83-95 parts of Al₂O₃, ii) 4-11 parts of the pigment, and iii) 1-6 parts of the additive； preferably i) 88-92 parts of Al₂O₃； ii) 7-9 parts of the pigment； and iii) 2 -3.5 parts of the additive. In one preferred embodiment, the black alumina ceramic powder comprises by weight of i) 90 parts of Al₂O₃, ii) 8 parts of the pigment, and iii) 3 parts of the additive.

In various embodiments, the black alumina ceramic powder comprises Fe₂O₃, NiO, MnO₂ and Co₂O₃ in a ratio by weight of 2-4 : 0.25-0.75 : 2-4 : 0.25-0.75； preferably 3 : 0.5 : 3 : 0.5.

In another aspect, the invention provides a process for producing the black alumina ceramic powder according to the invention, comprising the following steps:

1) weighing and mixing Fe₂O₃, NiO, MnO₂ and Co₂O₃,

2) firing the mixture at 1050℃～1250℃ for 1～4h and cooling the fired material to obtain a black pigment, and

In step 1) , Fe₂O₃, NiO, MnO₂ and Co₂O₃. are weighed according to the formulation, and then mixed in a mixing device. Preferably, Fe₂O₃, NiO, MnO₂ and Co₂O₃ are mixed with agate ball in an agate pot. There is no particular limitation for the mixing procedure, it may be performed for any long period so that the components are mixed homogenously. Preferably, the mixing is performed for about 6-12 hours.

In step 2) , the mixture obtained in step 1) is fired in a furnace at a temperature between 1050℃～1250℃, preferably at 1150℃. There is no particular limitation for the firing period. Preferably, the firing period is about 1 to 4 hour. After fired, the mixture is cooled in the furnace to the room temperature, so that the black pigment is obtained.

In step 3) , Al₂O₃, the black pigment, SiO₂, TiO₂ and La₂O₃ are weighed according to the formulation, and then mixed in a mixing device, preferably with agate ball in an agate pot. The mixing procedure may be performed for any long period so that the components are mixed homogenously. Preferably, the mixing will be performed for about 6-18 hours. Then a black alumina ceramic powder is obtained.

In a still further aspect, the invention provides a first process for producing a black alumina ceramic body, comprising the following steps:

1) weighing the black alumina ceramic powder according to the invention； adding a solvent, a dispersing agent, a binder and a plasticizer； milling； and tape casting after vacuuming to form a green body, and

The solvent used in step 1) is preferably mixed solvents composed of ethanol, xylene and isopropanol. Preferably, the ethanol, xylene and isopropanol are contained in the solvents in a ratio by weight of 6-15: 1-6: 9-22. More preferably, the ethanol, xylene and isopropanol are contained in the solvents in a ratio by weight of 7-11 : 2-5 : 11-20.

The dispersing agent used in step 1) can be those generally used in the field of black alumina ceramic. In one embodiment, castor oil is used as the dispersing agent.

The binder used in step 1) can be those generally used in the field of black alumina ceramic, such as polyvinyl alcohol or polyvinyl butyral. In one embodiment, polyvinyl butyral is used as the binder.

The plasticizer used in step 1) can be those generally used in the field of black alumina ceramic. In one embodiment, dibutyl phthalate is used as the plasticizer.

The milling procedure in step 1) may be performed in an external mixer. There is no particular limitation for the milling period. In one embodiment, the milling period is preferably 3 to 6 hour. After milling, the milled mixture is subject to tape casting after vacuuming. Then a green body is obtained.

In step 2) , the green body is sintered in a furnace at a temperature between 1250℃～1350℃, preferably at 1300℃. There is no particular limitation for the sintering period. In the invention, the sintering period is preferably 1 to 4 hours, more preferably 2 to 3 hours. In one embodiment, the sintering period is 3 hours.

Yet in a further aspect, the invention provides a second process for producing a black alumina ceramic body, comprising the following steps:

1) pelletizing the black alumina ceramic powder as claimed in any of claims 1 to 6 with a binder to form green body, and

2) sintering the green body at 1250-1350℃ for 1-4h to produce the black alumina ceramic body.

In the second process for producing the black alumina ceramic powder, step 2) is the same as the step 2) of the first process described above. The second process differs only in the step 1) , i.e. pelletizing the black alumina ceramic powder with a binder to form green body.

The binder used in step 1) for pelletizing the black alumina ceramic powder can be any binder used in the field of black alumina ceramic powder. In one embodiment of the invention, polyvinyl alcohol is preferably used.

In a further aspect, the invention provides a black alumina ceramic body obtained by the processes above.

The black alumina ceramic exhibits excellent properties, such as density, shrinkage, electrical properties and mechanical properties. Therefore, the black alumina ceramic body is suitable for industrial application, especially integrated circuit industry.

Testing

The properties of the products produced in the Examples were tested as below.

Bulk density: Archimedes method was employed to determine the bulk density of the sintered sample. A sample was placed in a flask, to which appropriate amount of water was added to fully immerse the sample. After having been boiled in water for 40 min, the immersed weight m₂ (g) and the water-saturated weight m₃ (g) of the sample were measured using a precision electronic analytical balance； the dry weight m₁(g) was measured after drying at 110℃. Bulk density ρ of the sample can be calculated as follows :

where ρ₀ is the density of water at room temperature

Porosity: it is measured according to standard GB/T 2997-2000

Shrinkage: it is measured according to standard QB_T 1548-1992

Volume resistivity test: Japanese SM-8205 megohmmeter was used to measure the volume resistance (R_v) of the sample at room temperature. Volume resistivity (P_v) can be calculated using the equation :

Where π —3.1416；

h —sample’s thickness in cm；

Ф—sample’s diameter in cm.

Dielectric property test: High-frequency dielectric properties of the sample were measured using a Hakki-Coleman dielectric resonance method for determination of dielectric constant ε_r and dielectric loss, the instrument used was HP8722ET network analyzer from Agilent (US) , the resonant mode was TE₀₁₁.

During the measurement, basing on the analyzed full diagram of the resonator, the network analyzer can calibrate the resonant frequency f₀ of a specific mode and the half-height of the resonant peak, from which the dielectric constant and the dielectric loss can be further calculated.

Three-point bending strength: it is measured according to standard GB/T 6569-1986

Examples

The materials Al₂O₃, Fe₂O₃, NiO, MnO₂, Co₂O₃, SiO₂, TiO₂, La₂O₃, PVA and PVB used in the following examples are all CP or AR grade being available in the market.

Example 1: preparation of black alumina ceramic powders and black alumina ceramic bodies

According to the formulations shown in Table 1, Fe₂O₃, NiO, MnO₂ and Co₂O₃ were weighed and mixed with agate ball in the agate pot for about 12 hours. The mixed materials were fired at 1150℃ for 2.5 hours. The fired materials were cooled to obtain a black pigment.

Al₂O₃, the black pigment, SiO₂, TiO₂ and La₂O₃ were weighed according to the formulations shown in Table 1, then mixed with agate ball in the agate pot for about 12 hours. Three black alumina ceramic powder are obtained (No. 1, 2 and 3)

Each of the three black alumina ceramic powders was pelletized with PVA and a green body was obtained. The green body was sintered at 1300℃, and a black alumina ceramic body was obtained. The properties of the black alumina ceramic body were tested and shown in the table 2.

Table 1 Formulations of Example 1 (parts by weight)

Table 2 Properties of the black alumina ceramic bodies obtained in Example 1

Example 2: preparation of black alumina ceramic powders and black alumina ceramic bodies

According to the formulations shown in Table 3, Fe₂O₃, NiO, MnO₂and Co₂O₃ were weighed and mixed with agate ball in the agate pot for about 12 hours. The mixed materials were fired at 1150℃ for 2.5 hours, then being cooled to obtain a black pigment.

Al₂O₃, the black pigment, SiO₂, TiO₂ and La₂O₃ were weighed according to the formulations shown in Table 3, then mixed with agate ball in the agate pot for about 12 hours. Three black alumina ceramic powders are obtained (No. 1, 2 and 3) .

Each of the three black alumina ceramic powders was pelletized with PVA and a green body was obtained. The green body was sintered at 1300℃, and a black alumina ceramic body was obtained. The properties of the black alumina ceramic bodies were tested and shown in the table 4.

Table 3 Formulations of Example 2 (parts by weight)

Table 4 Properties of the black alumina ceramic bodies obtained in Example 2

Example 3: Preparation of black alumina ceramic bodies

According to the formulations shown in Table 5, the black alumina ceramic powder prepared in Example 1, ethanol, xylene, isopropanol and castor oil were weighed and mixed in the agate pot for about 4.5 hours. Then, polyvinyl butyral and dibutyl phthalate were weighed and added into the mixture, which were further milled for 4.5 hours. Then, the mixture was subject to tape casting after vacuuming, and a green body was obtained.

The green body was sintered at 300℃ for 4 hours, and a black alumina ceramic body was obtained. The properties of the black alumina ceramic body were tested and shown in the table 6.

Table 5 Formulations of Example 3 (parts by weight)

Table 6 Properties of the black alumina ceramic bodies obtained in Example 3

Example 4 : Preparation of black alumina ceramic bodies

According to the formulations shown in Table 7, the black alumina ceramic powder prepared in Example 2, ethanol, xylene, isopropanol and castor oil were weighed and mixed in the agate pot for about 4.5 hours. Then, polyvinyl butyral and dibutyl phthalate were weighed and added into the mixture, which were further milled for 4.5 hours. Then, the mixture was subject to tape casting after vacuuming, and a green body was obtained

The green body was sintered at 300℃ for 4 hours, and a black alumina ceramic body was obtained. The properties of the black alumina ceramic body were tested and shown in the table 8.

Table 7 Formulations of Example 4 (parts by weight)

Table 8 Properties of the black alumina ceramic bodies obtained in Example 4

Claims

A black alumina ceramic powder, which comprises:

i) Al₂O₃；

ii) a pigment composed of Fe₂O₃, NiO, MnO₂ and Co₂O₃； and

iii) an additive selected from the group consisting of SiO₂, TiO₂ and La₂O₃ and combination thereof.
The black alumina ceramic powder as claimed in claim 1, which does not comprise a Cr-containing component.
The black alumina ceramic powder as claimed in claim 1 or 2, which comprises by weight of:

i) 83-95 parts of Al₂O₃；

ii) 4-11 parts of the pigment； and

iii) 1-6 parts of the additive.
The black alumina ceramic powder as claimed in any of claims 1 to 3, which comprises by weight of:

i) 88-92 parts of Al₂O₃；

ii) 7-9 parts of the pigment； and

iii) 2-3.5 parts of the additive.
The black alumina ceramic powder as claimed in any of claim 1 to 4, wherein the ratio by weight of Fe₂O₃, NiO, MnO₂ and Co₂O₃ is 2-4 : 0.25-0.75 : 2-4 : 0.25-0.75.
The black alumina ceramic powder as claimed in any of claim 1 to 5, wherein the ratio by weight of Fe₂O₃, NiO, MnO₂ and Co₂O₃ is 3 : 0.5 : 3 : 0.5.
A process for producing a black alumina ceramic body, comprising the following steps:

1) weighing the black alumina ceramic powder according to any of claims 1 to 6； adding a solvent, a dispersing agent, a binder and a plasticizer； milling； and tape casting after vacuuming to form a green body； and

2) sintering the green body at 1250-1350℃ for 1～4 hours to produce the black alumina ceramic body.
The process as claimed in claim 7, wherein the solvent is composed of ethanol, xylene and isopropanol.
The process as claimed in claim 8, wherein the ratio by weight of the ethanol, xylene and isopropanol is 7-11 : 2-5 : 11-20.
The process as claimed in any of claims 7-9, wherein the binder is polyvinyl alcohol or polyvinyl butyral.
The process as claimed in any of claims 7-10, wherein the binder is polyvinyl butyral.
A black alumina ceramic body produced by the process as claimed in any of claims 7-11.
A process for producing a black alumina ceramic body, comprising the following steps:

1) pelletizing the black alumina ceramic powder as claimed in any of claims 1 to 6 with a binder to form a green body； and

2) sintering the green body at 1250-1350℃ for 1-4 hours to produce the black alumina ceramic body.
The process as claimed in claim 13, wherein the binder is polyvinyl alcohol or polyvinyl butyral.
The process as claimed in claim 13 or 14, wherein the binder is polyvinyl alcohol.
A black alumina ceramic body produced by the process as claimed in any of claims 13-15.