Alumina-zirconia sintered plate

Abstract

To provide a highly reliable alumina-zirconia sintered plate having high toughness.SOLUTION: An alumina-zirconia sintered plate is provided, which comprises Al2O3, ZrO2, Y2O3, and CaO, and, in an analysis result of the alumina-zirconia sintered plate, has a Y2O3 / ZrO2 mass ratio of 0.0280 to 0.0420, a fracture toughness of 3.95 to 4.90 Mpa m1 / 2, and a three-point bending strength of 500 to 600 MPa.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an alumina-zirconia sintered plate. [Background technology]

[0002] Patent Document 1 reports that when nano-zirconia particles are dispersed in a matrix of alumina particles, an alumina-zirconia composite ceramic body having high strength and a porosity of up to 2.2% can be obtained.

[0003] The alumina-zirconia sintered substrate previously proposed by the applicant in Patent Document 2 had a high three-point bending strength of 557 MPa for an example sample with a porosity of 4.1% (to increase the light reflectance for mounting a light-emitting element), and a very high three-point bending strength of 705 MPa for a comparative example sample with a porosity of 0.8%. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-24128 A [Patent Document 2] Patent No. 5850450 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is a problem with alumina-zirconia sintered plates in that increasing the strength reduces their toughness, making them vulnerable to shocks and reducing their reliability.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an alumina-zirconia sintered plate having high toughness and high reliability. [Means for solving the problem]

[0007] [1] Analysis of alumina-zirconia sintered plates shows that ZrO2: 4.54-8.02wt%, Y2O3: 0.13-0.33wt%, SiO2: 0.20~0.44wt%, MgO: 0.09 to 0.25 wt%, CaO: 0.05 to 0.17 wt%, HfO2: 0.09-0.17wt%, and the balance comprises Al2O3, Fracture toughness is 3.95 to 4.90 MPa m 1 / 2 Alumina-zirconia sintered plate.

[0008] [2] The alumina-zirconia sintered plate according to the above [1], wherein the Y2O3 / ZrO2 mass ratio is 0.0280 to 0.0420.

[0009] [3] The alumina-zirconia sintered plate according to the above [1] or [2], having a three-point bending strength of 500 to 600 MPa.

[0010] [4] The alumina-zirconia sintered plate according to any one of the above [1] to [3], which has a specific gravity of 3.89 or more.

[0011] [5] The alumina-zirconia sintered plate according to any one of the above [1] to [4], having a porosity of 0.6% or less.

[0012] [6] Contains Al2O3, ZrO2, Y2O3, and CaO, Analysis of the alumina-zirconia sintered plate showed that the Y2O3 / ZrO2 mass ratio was 0.0280-0.0420. Fracture toughness is 3.95 to 4.90 MPa m 1 / 2 and Alumina-zirconia sintered plate with a three-point bending strength of 500-600MPa.

[0013] [7] Fracture toughness is 3.95 to 4.90 MPa m 1 / 2 and The three-point bending strength is 500 to 600 MPa. Alumina-zirconia sintered plate with a porosity of 0.6% or less.

[0014] [8] A circuit board using the alumina-zirconia sintered plate according to any one of the above [1] to [7].

[0015] [9] A heat dissipation member using the alumina-zirconia sintered plate according to any one of the above [1] to [7].

[0016]

[10] An insulating member using the alumina-zirconia sintered plate according to any one of the above [1] to [7].

[0017]

[11] The amount of ingredients: ZrO2: 5.66-9.43wt%, Y2O3: 0.14~0.35wt%, SiO2: 0.30~0.47wt%, MgO: 0.08-0.24wt%, CaO: 0.05 to 0.11 wt%, HfO2: 0.11-0.18wt%, The remaining raw material powder of Al2O3 was mixed and ground so that the average particle size (D50) after mixing and grinding was 1.43 to 1.58 μm, A method for producing an alumina-zirconia sintered plate, comprising firing and sintering a compact made of the mixed and pulverized raw material powder.

[0018]

[12] The method for producing an alumina-zirconia sintered plate according to the above

[11] , wherein the Y2O3 / ZrO2 mass ratio is 0.0250 to 0.0380.

[0019]

[13] The method for producing an alumina-zirconia sintered plate according to the above

[11] or

[12] , wherein the firing is carried out at a temperature of 1530 to 1600°C for 2 to 4 hours.

[0020] [Effect] It is believed that tetragonal ZrO2 contributes to toughness. Y2O3 partially stabilizes tetragonal ZrO2, and therefore exists in the state of partially stabilized ZrO2 in solid solution in ZrO2. However, since the ratio of Y2O3 is appropriately low, the ratio of ZrO2 is relatively high, and toughness is increased. SiO2, MgO, and CaO are sintering aids that promote the grain growth of Al2O3 and lower the sintering temperature. In addition, the inclusion of an appropriate amount of CaO improves sinterability and toughness. If CaO is not included, sinterability decreases and voids form (Comparative Examples 4 and 5 described below), and if the content of CaO is too high, the particles become coarse and the voids between the particles increase. Effect of the Invention

[0021] According to the present invention, a highly reliable alumina-zirconia sintered plate having high toughness can be provided. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is an SEM image of Example 1 (porosity 0.4%). [Diagram 2] FIG. 2 is an SEM image of Comparative Example 6 (porosity: 0.8%). [Diagram 3] FIG. 3 is an SEM image of Comparative Example 7 (porosity: 1.4%). [Figure 4] FIG. 4 is an SEM image of Comparative Example 4 (porosity: 3.0%). [Diagram 5] FIG. 5 is a graph showing the relationship between the amount of ZrO2 and the three-point bending strength and fracture toughness. [Figure 6] FIG. 6 is a graph showing the relationship between the average particle size (D50) of the raw materials after mixing and pulverization and the three-point bending strength and fracture toughness. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] <1> Method for manufacturing alumina-zirconia sintered plate (A) The Y2O3 / ZrO2 mass ratio is preferably 0.0280 to 0.0420, and more preferably 0.0330 to 0.0360. This is because the ratio of Y2O3 is appropriately low, which relatively increases the ratio of ZrO2 and increases toughness.

[0024] (a) Firing is preferably performed at a temperature of 1530 to 1600°C for 2 to 4 hours, more preferably 2.5 to 4 hours. If the temperature is lower than 1530°C, sintering is insufficient and sufficient plate strength cannot be obtained. If the temperature is higher than 1600°C, grain growth proceeds.

[0025] <2> Alumina-zirconia sintered plate (A) The plate thickness is not particularly limited, but is preferably 0.08 mm or more. If it is thinner than 0.08 mm, it will be weak against external stress. If it is too thick, it will simply become difficult to form, so there is no particular upper limit, but 5 mm is the preferred upper limit.

[0026] (a) The porosity is preferably 0.6% or less, and more preferably 0.5% or less. Insufficient or excessive sintering will increase the number of voids, so porosity is an indicator of the degree of sintering. Low porosity is thought to ensure strength and toughness.

[0027] (c) Fracture toughness: 3.95 to 4.90 MPa m 1 / 2 Preferably, the resistance is 4.20 to 4.90 MPa m 1 / 2 It is more preferable that: Fracture toughness is 3.95 MPa m 1 / 2 As a result, the device is more resistant to shocks and has improved reliability.

[0028] (d) The three-point bending strength is preferably from 500 to 600 MPa, and more preferably from 530 to 600 MPa. While a general-purpose alumina sintered plate has a three-point bending strength of about 450 MPa, the alumina-zirconia sintered plate of the present invention has a three-point bending strength of 500 MPa or more. Therefore, it can fully withstand large external stresses that a general-purpose alumina sintered plate cannot withstand, and it can also be made thinner.

[0029] <3> Purpose The uses of the alumina-zirconia sintered plate of the present invention are not particularly limited, but examples thereof include circuit boards, heat sinks, insulating plates, and high-frequency windows used in semiconductor modules, LED packages, Peltier modules, printers, multifunction machines, semiconductor lasers, optical communications, and high frequencies. EXAMPLES

[0030] Next, examples embodying the present invention will be described in comparison with comparative examples. Note that the materials, quantities and conditions of each part in the examples are merely examples and can be appropriately changed without departing from the gist of the invention.

[0031] Alumina-zirconia sintered plates of Examples 1 to 16 and Comparative Examples 1 to 7 shown in Tables 1 to 3 were produced.

[0032] [Table 1]

[0033] [Table 2]

[0034] [Table 3]

[0035] First, in the compounding process, 0.5 parts by weight of a surfactant dispersant and 20 parts by weight of a mixed solvent of xylene and isopropyl alcohol were added to raw material powders of Al2O3, ZrO2, Y2O3, SiO2, MgO, CaO and HfO2 in the compounding ratios shown in the "Charge" columns of Tables 1 to 3, with the total amount of the raw material powders being 100 parts by weight.

[0036] For ZrO2 and Y2O3, the following products were used: In Examples 1 to 3, 6 to 16 and Comparative Examples 1, 4 to 7, a ZrO2 powder product (DURAZR series zirconia for fine ceramics manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) containing 1.5 molar parts of Y2O3 powder was used. The Y2O3 / ZrO2 mass ratio was 0.0318. In Example 4, in order to make the ZrO2 mass ratio lower than in Example 1, the above-mentioned DURAZR series was blended with ZrO2 powder not mixed with Y2O3. In Example 5 and Comparative Examples 2 and 3, in order to increase the ZrO2 mass ratio compared to Example 1, the above-mentioned DURAZR series was blended with a ZrO2 powder product (zirconia for fine ceramics HSY-3F manufactured by the same company) mixed with 3 molar parts of Y2O3 powder.

[0037] Examples 1 to 3 and Comparative Example 1 are groups in which the blending amounts of the above-mentioned DURAZR series were changed, mainly changing the amounts of ZrO2 and Y2O3. Examples 4 and 5 and Comparative Examples 2 and 3 are groups in which the blend amounts were changed, mainly the amount of Y2O3. Examples 6 to 9 and Comparative Examples 4 to 7 are groups in which the CaO content was mainly changed. Examples 10 to 12 are a group in which the amounts of SiO2, MgO, and CaO were mainly changed.

[0038] The raw material powder after the above addition was crushed and mixed using alumina balls so that the particle size after crushing and mixing would be as follows. In Example 1, as a result of grinding and mixing for a predetermined time, the particle sizes after grinding and mixing were D90: 3.02 μm, D50: 1.50 μm, and D10: 0.52 μm. In Examples 2 to 12 and Comparative Examples 1 to 7, the particles were pulverized and mixed for the same time as in Example 1, and therefore the particle size after pulverization and mixing is considered to be equivalent to that of Example 1 (so the measurement of particle size was omitted). In Examples 13 to 16, the particles were ground and mixed for shorter or longer times than in Example 1, resulting in particle sizes D90: 2.84 to 3.28 μm, D50: 1.43 to 1.58 μm, and D10: 0.51 to 0.52 μm after grinding and mixing. Table 3 lists Example 1 again, with Examples 10 to 13 sandwiched between it. The particle size was measured by adding 0.5 g of the raw powder after grinding and mixing to 50 ml of 0.1% by mass aqueous solution of sodium pyrophosphate, dispersing it for 3 minutes at 80% output using a US-300E manufactured by Nippon Seiki Seisakusho, and then measuring the particle size using a laser diffraction scattering method using a SALD-2200 manufactured by Shimadzu Corporation.

[0039] Thereafter, 7 parts by weight of polyvinyl butyral as a binder, 3 parts by weight of dioctyl adipate as a plasticizer, and 20 parts by weight of the same solvent as described above were added, and the mixture was stirred and mixed in a ball mill until the binder was completely dissolved and mixed, and then a slurry was prepared.

[0040] The slurry was applied onto a film by a doctor blade method, and the solvent was evaporated by drying at 70 to 120° C. After that, the film was peeled off to obtain a green sheet.

[0041] The obtained green sheet was pressed into a predetermined shape, organic components were removed at 300 to 500°C, and the sheet was fired at 1560°C for 3 hours to obtain an alumina-zirconia sintered plate (ceramic sintered plate) having a thickness of 0.38 mm.

[0042] The following analyses and measurements were carried out on the obtained alumina-zirconia sintered plates of Examples 1 to 16 and Comparative Examples 1 to 7. The analysis and measurement results are shown in Tables 1 to 3.

[0043] (1) Composition analysis of alumina-zirconia sintered plate The composition of the alumina-zirconia sintered plate was analyzed by a scanning X-ray fluorescence analyzer (XRF) (ZSX Primus IV, manufactured by Rigaku Corporation).

[0044] (2) Specific gravity The specific gravity ρ was calculated by Archimedes' method as follows: W1 is the dry mass of the substrate, W2 is the mass of the saturated substrate in water, and W3 is the mass of the saturated substrate after wiping off the water on the substrate surface.

[0045] (3) Porosity The porosity was determined by observing the mirror-polished and thermally etched substrate surface with a scanning electron microscope, measuring the pore area for each of five randomly selected 5,000x SEM images, and calculating the average pore area relative to the observed area.

[0046] (4) Three-point bending strength The three-point bending strength was measured using an AGX-V manufactured by Shimadzu Corporation, based on JIS R1601:2008 (room temperature bending strength test method for fine ceramics).

[0047] (5) Fracture toughness The fracture toughness was measured using the HV-120B manufactured by Mitutoyo Corporation by the IF method based on JIS R1607:2015 (Room temperature fracture toughness test method for fine ceramics).

[0048] FIG. 1 is an SEM image of Example 1 (porosity 0.4%). FIG. 2 is an SEM image of Comparative Example 6 (porosity: 0.8%). FIG. 3 is an SEM image of Comparative Example 7 (porosity: 1.4%). FIG. 4 is an SEM image of Comparative Example 4 (porosity: 3.0%). In these SEM images, the white areas are ZrO2 (partially stabilized zirconia) and the black areas are pores. FIG. 5 is a graph plotting Comparative Example 1 and Examples 1 to 3, showing the relationship between the amount of ZrO2 charged and the three-point bending strength and fracture toughness. FIG. 6 is a graph plotting Examples 1, and 10 to 13, showing the relationship between the average particle size (D50) after mixing and pulverizing the raw materials and the three-point bending strength and fracture toughness.

[0049] Comparative Examples 1 to 7 have a three-point bending strength of less than 500 MPa and / or a fracture toughness of 3.95 MPa m 1 / 2 It was less than. In contrast, in Examples 1 to 16, the three-point bending strength was 500 MPa or more and the fracture toughness was 3.95 MPa m 1 / 2 That was all. In particular, Examples 1 to 5 and 8 to 16 have a three-point bending strength of 516 MPa or more and a fracture toughness of 4.13 MPa m 1 / 2 Above all, it is particularly excellent.

[0050] The present invention is not limited to the above-described embodiment, and can be embodied by making appropriate modifications without departing from the gist of the invention.

Claims

1. A ２ O ３ and ZrO ２ and Y ２ O ３ and CaO, The analysis results of alumina-zirconia sintered plates show that Y ２ O ３ / ZrO ２ The mass ratio is 0.0280 to 0.0420, Fracture toughness: 3.95 to 4.90 MPa m １／２ and An alumina-zirconia sintered plate having a three-point bending strength of 500 to 600 MPa.

2. 2. The alumina-zirconia sintered plate according to claim 1, having a porosity of 0.6% or less.

3. A circuit board using the alumina-zirconia sintered plate according to claim 1 or 2.

4. A heat dissipating member using the alumina-zirconia sintered plate according to claim 1 or 2.

5. An insulating member using the alumina-zirconia sintered plate according to claim 1 or 2.

6. The amount of preparation, ZrO ２ :5.66~9.43wt%、 Y ２ O ３ :0.14~0.35wt%、 Yes ２ :0.30~0.47wt%、 MgO: 0.08 to 0.24 wt%, CaO: 0.05 to 0.11 wt%, HfO ２ :0.11~0.18wt%、 and the balance is Al ２ O ３ The raw material powders are mixed and pulverized so that the average particle size (D50) after mixing and pulverization is 1.43 to 1.58 μm, The mixed and pulverized raw material powder is molded into a plate-shaped compact, A method for producing an alumina-zirconia sintered plate, comprising firing and sintering the plate-shaped molded body.

7. Y ２ O ３ / ZrO ２ The method for producing an alumina-zirconia sintered plate according to claim 6, wherein the mass ratio is 0.0250 to 0.0380.

8. The method for producing an alumina-zirconia sintered plate according to claim 6 or 7, wherein the firing is carried out at a temperature of 1530 to 1600° C. for 2 to 4 hours.

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