Joined body

Abstract

To provide a joined body of a ceramic plate and an MMC plate, which has high joint strength.SOLUTION: A joined body comprises: a ceramic plate; an MMC plate provided opposite one side of the ceramic plate and composed of a metal matrix composite (MMC); and a joining layer provided between the ceramic plate and the MMC plate and joining the ceramic plate and the MMC plate, the joining layer comprising Al as a main component and Si and Mg as secondary components, wherein a bonding interface between the ceramic plate and the joining layer includes a Mg-containing layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a bonded body.

Background Art

[0002] In semiconductor device manufacturing, circuit formation is generally performed by plasma etching. Plasma etching is performed by introducing an inert gas into a vacuum chamber in a plasma etching apparatus to form a plasma. In the plasma etching apparatus, an electrostatic chuck assembly is provided that functions as a susceptor on which a wafer to be etched is placed. A typical electrostatic chuck assembly includes an electrode-embedded ceramic plate that functions as an electrostatic chuck and a cooling plate that supports the bottom surface of the electrode-embedded ceramic plate. The wafer is electrostatically adsorbed to the electrode-embedded ceramic plate, and plasma etching is performed while being fixed to the electrostatic chuck assembly. On the other hand, the cooling plate is provided on the bottom surface of the electrode-embedded ceramic plate and is configured to take away the heat generated in the wafer by plasma etching. The electrode-embedded ceramic plate generally has a configuration in which internal electrodes such as an electrostatic chuck (ESC) electrode, an RF electrode, and a heater electrode are embedded inside a ceramic substrate made of aluminum oxide, aluminum nitride, or the like, which has excellent heat resistance and corrosion resistance.

[0003] As an example of an electrostatic chuck assembly, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2009-141204) discloses a substrate holder in which a first substrate made of a first ceramic sintered body and a second substrate made of a second ceramic sintered body are joined via a bonding film of a metal containing Al. This document discloses that the first substrate and the second substrate are joined via the bonding film by thermocompression bonding at a pressure of 4 to 20 MPa while heating the metal with the bonding film of the metal containing Al sandwiched between the first substrate and the second substrate, and it is desirable that the metal containing Al is an Al alloy containing Mg in the range of 0.5 to 5% by weight.

[0004] By the way, in recent years, metal matrix composites (MMCs) have attracted attention. A metal matrix composite is a material in which a ceramic reinforcing material such as SiC or TiC is combined with a metal matrix composed of a metal such as Al or metallic Si, and is known to have advantages such as light weight, high rigidity, high thermal conductivity, and low thermal expansion. A method of joining a metal matrix composite (MMC) and a ceramic material has been proposed. Patent Document 2 (Japanese Patent No. 4373538) discloses a joined body in which an MMC containing an aluminum alloy as a matrix and a ceramic material are joined via a brazing material composed of an Al alloy containing Mg.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0006] As a cooling plate of an electrostatic chuck assembly, it is desirable to use an MMC plate because of advantages such as high thermal conductivity and low thermal expansion. Therefore, improvement in the bonding strength in a joined body of an MMC plate and a ceramic plate has been demanded.

[0007] The present inventors have now found that by (1) providing a predetermined bonding layer between an MMC plate and a ceramic plate, and (2a) making the bonding interface between the ceramic plate and the bonding layer include a Mg-containing layer, and / or (2b) making the MMC plate have an Al diffusion layer over a predetermined depth (thickness) from the bonding interface between the bonding layer and the MMC plate, a joined body of a ceramic plate and an MMC plate having high bonding strength can be provided.

[0008] Accordingly, an object of the present invention is to provide a joined body of a ceramic plate and an MMC plate having high joining strength.

[0009] According to the present disclosure, the following aspects are provided. [Aspect 1] A ceramic plate, an MMC plate provided to face one side of the ceramic plate and composed of a metal matrix composite (MMC), a joining layer provided between the ceramic plate and the MMC plate for joining the ceramic plate and the MMC plate, the joining layer containing Al as a main component and containing Si and Mg as sub-components, and a joined body including the same, wherein a joining interface between the ceramic plate and the joining layer includes a Mg-containing layer. Joined body. [Aspect 2] The joined body according to Aspect 1, wherein the Mg-containing layer further contains Al and O. [Aspect 3] The joined body according to Aspect 2, wherein a weight ratio of Al:Mg:O in the Mg-containing layer is 1:0.01 to 0.50:0.001 to 0.100. [Aspect 4] The joined body according to Aspect 1 or 2, wherein a thickness of the Mg-containing layer is 1 to 10 μm. [Aspect 5] The joined body according to any one of Aspects 1 to 3, wherein joining of the ceramic plate, the joining layer, and the MMC plate is thermocompression bonding. [Aspect 6] The joined body according to any one of Aspects 1 to 3, wherein the metal matrix composite (MMC) contains Si, C, and Ti. [Aspect 7] The joined body according to any one of Aspects 1 to 4, wherein the MMC plate has an Al diffusion layer in which Al derived from the joining layer is diffused over a predetermined depth D Al from a joining interface between the joining layer and the MMC plate. [Aspect 8] The MMC plate has an Mg diffusion layer in which Mg derived from the bonding layer is diffused over a predetermined depth D from the bonding interface between the bonding layer and the MMC plate, the bonded body according to aspect 7. Mg [Aspect 9] [Aspect 9] The depth D of the Al diffusion layer Al is greater than the depth D of the Mg diffusion layer Mg i.e., D Al > D Mg satisfies the bonded body according to aspect 8. [Aspect 10] The surface on the bonding interface side of the MMC plate has an arithmetic mean roughness Ra of 0.01 to 1.0 μm, the bonded body according to any one of aspects 1 to 9. [Aspect 11] Exhibits a bonding strength of 200 MPa or more in a four-point bending test, the bonded body according to any one of aspects 1 to 10. [Aspect 12] The ceramic plate contains aluminum oxide and / or aluminum nitride and has internal electrodes embedded therein, the bonded body according to any one of aspects 1 to 11. [Aspect 13] A ceramic plate, An MMC plate provided opposite to one side of the ceramic plate and composed of a metal matrix composite (MMC) containing Si, C, and Ti, A bonding layer provided between the ceramic plate and the MMC plate for bonding the ceramic plate and the MMC plate, the bonding layer containing Al as a main component and containing Si and Mg as sub-components, Comprising, the MMC plate having an Al diffusion layer in which Al derived from the bonding layer is diffused over a predetermined depth D from the bonding interface between the bonding layer and the MMC plate, the depth D of the Al diffusion layer Al is 40 μm or more, the bonded body. Al [Aspect 14] [Aspect 14] The MMC plate has an Al diffusion layer in which Al derived from the bonding layer is diffused over a predetermined depth D from the bonding interface between the bonding layer and the MMC plate, the depth D MgThe bonded body according to aspect 13, having an Mg diffusion layer in which Mg derived from the bonding layer has been diffused over it. [Aspect 15] The depth D of the Al diffusion layer Al is greater than the depth D of the Mg diffusion layer Mg i.e., D Al > D Mg The bonded body according to aspect 14, which satisfies this. [Aspect 16] The bonded body according to any one of aspects 13 to 15, wherein the ceramic plate contains aluminum oxide and / or aluminum nitride and has internal electrodes embedded therein. [Aspect 17] The bonded body according to any one of aspects 13 to 16, wherein the bonding of the ceramic plate, the bonding layer, and the MMC plate is thermocompression bonding. [Aspect 18] The bonded body according to any one of aspects 13 to 17, wherein the surface on the bonding interface side of the MMC plate has an arithmetic mean roughness Ra of 0.01 to 1.0 μm. [Aspect 19] The bonded body according to any one of aspects 13 to 18, which exhibits a bonding strength of 200 MPa or more in a four-point bending test.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Mode for Carrying Out the Invention

[0011] Conjugate Fig. 1 shows an example of the joined body according to the present invention. The joined body 10 shown in Fig. 1 includes a ceramic plate 12, an MMC plate 14, and a joining layer 16. Preferably, the ceramic plate 12 contains aluminum oxide and / or aluminum nitride, and the internal electrode 18 is embedded therein. The MMC plate 14 is a plate made of a metal matrix composite (MMC), and is provided to face one side of the ceramic plate 12. The metal matrix composite (MMC) preferably contains Si, C, and Ti. The joining layer 16 is a layer that joins the ceramic plate 12 and the MMC plate 14, and is provided between the ceramic plate 12 and the MMC plate 14. The joining layer 16 mainly contains Al, and also contains Si and Mg as sub-components. In the first aspect of the present invention, the joining interface 20 between the ceramic plate 12 and the joining layer 16 includes a Mg-containing layer 24. On the other hand, in the second aspect of the present invention, as specifically shown in Fig. 2, the MMC plate 14 has an Al diffusion layer 26 in which Al derived from the joining layer 16 is diffused over a predetermined depth D Al from the joining interface 22 between the joining layer 16 and the MMC plate 14. The depth D Al of the Al diffusion layer is preferably 40 μm or more. The first aspect may include the features of the second aspect, and vice versa. Thus, by providing a predetermined joining layer 16 between the MMC plate 14 and the ceramic plate 12, and (2a) making the joining interface 20 between the ceramic plate 12 and the joining layer 16 include a Mg-containing layer 24, and / or (2b) making the MMC plate 14 have an Al diffusion layer 26 over a predetermined depth (thickness) from the joining interface 22 between the joining layer 16 and the MMC plate 14, a joined body 10 of the ceramic plate 12 and the MMC plate 14 having high joining strength can be provided. That is, by not only adopting a predetermined joining layer 16 but also providing a Mg-containing layer 24 and / or an Al diffusion layer 26, high joining strength can be achieved between the MMC plate 14 and the ceramic plate 12.

[0012] The ceramic plate 12 is a plate-shaped member including a ceramic sintered body, and may have the same configuration as a ceramic plate employed in a known ceramic susceptor (such as an electrostatic chuck assembly or a ceramic heater, etc.). Typically, an internal electrode 18 is embedded in the ceramic plate 12. The ceramic sintered body constituting the main portion (i.e., the ceramic substrate) other than the internal electrode 18 of the ceramic plate 12 preferably contains aluminum oxide and / or aluminum nitride from the viewpoints of excellent thermal conductivity, high electrical insulation, and thermal expansion characteristics close to those of silicon, and more preferably contains aluminum nitride. The ceramic sintered body constituting the ceramic plate 12 may contain additives such as MgO in addition to aluminum oxide and / or aluminum nitride. In this case, the content of aluminum oxide and / or aluminum nitride in the ceramic sintered body constituting the ceramic plate 12 is typically 50 to 100% by mass, and the balance may contain additives such as MgO. The thickness of the ceramic plate 12 can be the thickness of a general ceramic plate and is not particularly limited, but is typically 2 to 10 mm, and more typically may be 2 to 5 mm.

[0013] Examples of the internal electrode 18 embedded in the ceramic plate 12 include an ESC electrode, a heater electrode, and an RF electrode. Two types of internal electrodes 18 may be provided in the ceramic plate 12. The ESC electrode is an abbreviation of an electrostatic chuck (ESC) electrode and is also referred to as an electrostatic electrode. The ESC electrode is preferably a circular thin-layer electrode having a slightly smaller diameter than the ceramic plate 12. For example, it can be a mesh-shaped electrode formed by weaving thin metal wires into a net shape and forming a sheet. The ESC electrode may be used as a plasma electrode. That is, by applying a high frequency to the ESC electrode, the ESC electrode can also be used as a plasma electrode, and film formation by a plasma CVD process can also be performed. When a voltage is applied by an external power source, the ESC electrode chucks the wafer placed on the surface of the ceramic plate 12 by the Johnson-Rahbek force. The heater electrode is not particularly limited. For example, it can be a conductive coil wired in one stroke over the entire surface of the ceramic plate 12. When power is supplied from a heater power source, the heater electrode generates heat and heats the wafer placed on the surface of the ceramic plate 12. The heater electrode is not limited to a coil. For example, it may be a ribbon (an elongated thin plate) or a mesh. The ribbon-shaped heater electrode may be formed by a printing method.

[0014] The MMC plate 14 is made of a metal matrix composite (MMC). The MMC may be a known material in which a ceramic reinforcing material is compounded in a metal matrix and is not particularly limited. Examples of the metal matrix include aluminum and metal silicon. Examples of the ceramic reinforcing material include SiC and TiC. A preferred MMC contains Si, C, and Ti. Examples of the MMC containing Si, C, and Ti include a composite material containing 37 to 60% by mass of silicon carbide and containing titanium silicon carbide and titanium carbide in amounts smaller than the content (% by mass) of silicon carbide, respectively. The thickness of the MMC plate 14 is not particularly limited, but is typically 5 to 35 mm.

[0015] The surface of the MMC plate 14 on the bonding interface 22 side preferably has an arithmetic mean roughness Ra of 0.01 to 1.0 μm, more preferably 0.05 to 0.70 μm. When the arithmetic mean roughness Ra is within the above range, the bonding strength can be more effectively increased. This is presumably because the adhesion between the MMC plate 14 and the bonding layer 16 is improved by Ra not being too high, and because the anchor effect due to the surface roughness or unevenness of the MMC plate 14 is obtained by Ra not being too low.

[0016] The bonding layer 16 is a metal layer containing Al as a main component and containing Si and Mg as sub-components. Here, the "main component" means a component that occupies 80% by weight or more of the bonding layer 16. The "sub-component" is a component contained in a content lower than that of the main component (excluding inevitable impurities). Therefore, the bonding material constituting the bonding layer 16 is preferably an Al alloy containing Si and Mg. The Si content in this Al alloy is preferably 5 to 15% by weight. Also, the Mg content in this aluminum alloy is preferably 0.1 to 5.0% by weight. That is, the bonding layer 16 preferably comprises an Al alloy containing Si: 5 to 15% by weight, Mg: 0.5 to 5.0% by weight, with the balance being Al and inevitable impurities.

[0017] The bonding interface 20 between the ceramic plate 12 and the bonding layer 16 preferably includes an Mg-containing layer 24. The presence of the Mg-containing layer 24 at the bonding interface 20 improves the bonding strength between the ceramic plate 12 and the bonding layer 16, and as a result, it is considered that high bonding strength can be achieved between the ceramic plate 12 and the MMC plate 14. The Mg-containing layer 24 is identified as a layer containing Mg at a higher concentration than its surroundings at the bonding interface 20 in the elemental mapping image obtained by EPMA (electron probe microanalyzer). The Mg-containing layer 24 preferably further contains Al and O. In this case, the weight ratio of Al:Mg:O in the Mg-containing layer 24 is preferably in the range of 1:0.01 to 0.50:0.001 to 0.100, more preferably in the range of 1:0.05 to 0.30:0.005 to 0.050. The weight ratio of Al:Mg:O can be measured by EPMA. From the viewpoint of improving the bonding strength, the thickness of the Mg-containing layer 24 is preferably 1 to 10 μm, more preferably 1 to 7 μm.

[0018] The bonding of the ceramic plate 12, the bonding layer 16, and the MMC plate 14 is preferably thermocompression bonding. Thermocompression bonding refers to a method in which a metal bonding film (corresponding to the bonding layer 16) is sandwiched between two members to be bonded, and the two members are pressure-bonded while heating to a temperature below the liquidus temperature of the metal bonding film (see Patent Document 1).

[0019] As shown in FIG. 2, the MMC plate 14 has a predetermined depth D from the bonding interface 22 between the bonding layer 16 and the MMC plate 14 AlPreferably, it has an Al diffusion layer 26 in which Al derived from the bonding layer 16 has been diffused. As described above, by providing the Al diffusion layer 26, a high bonding strength can be achieved between the MMC plate 14 and the ceramic plate 12. The Al diffusion layer 26 is identified as a layer containing Al at a high concentration (higher than other regions of the MMC plate 14) observed in a region adjacent to the bonding interface 22 in the MMC plate 14 in an Al element mapping image obtained by EPMA, as exemplified in FIG. 5B described later. That is, in the Al element mapping image, when pixels showing a high concentration of Al are distributed continuously from the bonding layer 16 over a region adjacent to the bonding interface 22 of the MMC plate 14, it can be said that the Al observed at a high concentration in the adjacent region of the MMC plate 14 is Al derived from the bonding layer 16. Thus, the Al diffusion layer 26 is identified. The depth D of the Al diffusion layer 26 Al is preferably 40 μm or more, more preferably 40 to 600 μm, still more preferably 50 to 500 μm, and particularly preferably 250 to 500 μm.

[0020] As shown in FIG. 2, in addition to the Al diffusion layer 26, the MMC plate 14 has a predetermined depth D from the bonding interface 22 between the bonding layer 16 and the MMC plate 14 MgIt is also preferable to have an Mg diffusion layer 28 in which Mg derived from the bonding layer 16 has diffused. In this case, it at least partially overlaps with the Al diffusion layer 26 and the Mg diffusion layer 28 (that is, there is a portion in the MMC plate 14 that corresponds to both the Al diffusion layer 26 and the Mg diffusion layer 28). The Mg diffusion layer 28 is also considered to be able to contribute to the realization of high bonding strength together with the Al diffusion layer 26. As illustrated in FIG. 5B described later, the Mg diffusion layer 28 is identified as a layer containing Mg at a high concentration (compared to other regions of the MMC plate 14) in a region adjacent to the bonding interface 22 in the MMC plate 14 in the Mg element mapping image obtained by EPMA. That is, in the Mg element mapping image, when pixels showing a high concentration of Mg are continuously distributed from the bonding layer 16 over a region adjacent to the bonding interface 22 of the MMC plate 14, it can be said that the Mg observed at a high concentration in the adjacent region of the MMC plate 14 is Mg derived from the bonding layer 16. Thus, the Mg diffusion layer 28 is identified. The depth D of the Mg diffusion layer 28 Mg is preferably 10 to 300 μm, more preferably 20 to 200 μm, and even more preferably 90 to 180 μm. Typically, the depth D of the Al diffusion layer 26 Al is the depth D of the Mg diffusion layer 28 Mg is larger (that is, D Al >D Mg is satisfied).

[0021] The MMC plate 14 may have an internal space such as a flow path through which a refrigerant can pass inside. By doing so, the MMC plate 14 has a configuration suitable as a cooling plate of an electrostatic chuck assembly.

[0022] The bonded body 10 exhibits a bonding strength of preferably 200 MPa or more, more preferably 250 MPa or more, and even more preferably 300 MPa or more in a four-point bending test. The four-point bending test shall be conducted according to the procedures and conditions disclosed in the examples described below, and the maximum bending stress obtained thereby shall be adopted as the bonding strength. Since it is desirable that the bonding strength be high, the upper limit value is not particularly limited, but is typically 500 MPa or less, and more typically 450 MPa or less.

[0023] Method for producing conjugate The bonded body of the present invention may be manufactured by any method as long as a bonded body having a predetermined layer structure can be obtained. However, a preferred manufacturing method will be described below.

[0024] First, prepare a ceramic plate, an MMC plate, and a bonding layer in which internal electrodes are embedded. The details of each member are as described above. Any known ceramic plate, MMC plate, and bonding layer can be used, or they may be appropriately manufactured based on known methods.

[0025] Next, ultrasonic cleaning is performed on each of the ceramic plate, the MMC plate, and the bonding layer using an organic solvent. Ultrasonic cleaning can remove the dirt adhering to the surface of each member, improve the bonding property between each member and the bonding layer, and as a result, achieve high bonding strength. Preferred examples of the organic solvent include acetone and isopropyl alcohol (IPA). By increasing the ultrasonic cleaning time, dirt can be removed even more effectively, and the movement and diffusion of elements such as Mg and Al during thermocompression bonding can be promoted. Therefore, by controlling the ultrasonic cleaning time, in subsequent thermocompression bonding, the formation / non-formation of the Mg-containing layer can be controlled, and the depth (thickness) of the Al diffusion layer and the depth (thickness) of the Mg-containing layer can be changed. For example, by increasing the ultrasonic cleaning time, the Mg-containing layer can be formed, and the depth of the Al diffusion layer and the depth of the Mg-containing layer can be increased. From the viewpoint of more effectively removing the dirt adhering to the surface of each member, it is desirable to perform both ultrasonic cleaning using acetone and ultrasonic cleaning using isopropyl alcohol (IPA). The ceramic plate and the MMC plate subjected to ultrasonic cleaning are further cleaned by performing running water cleaning using pure water, blowing with N 2 gas, wiping with a wiping sheet impregnated with an organic solvent (such as IPA), and drying. Also, the bonding layer subjected to ultrasonic cleaning is preferably further cleaned by blowing with N 2 gas.

[0026] Using the thus purified ceramic plate, MMC plate, and bonding layer, a bonded body is produced by thermocompression bonding. For example, a bonding layer is sandwiched between the ceramic plate and the MMC plate, and while heating to a temperature below the liquidus temperature of the bonding material film, thermocompression bonding is performed at a pressure of 4 MPa to 30 MPa to bond the ceramic plate and the MMC plate via the bonding layer. The thermocompression bonding temperature is desirably below the liquidus temperature of the bonding layer and at a temperature of about 30 °C or more lower than the solidus temperature. For example, the liquidus temperature of an aluminum alloy containing 10 wt% Si and 1 wt% Mg is about 590 °C, and the solidus temperature is about 560 °C. Therefore, in this case, the thermocompression bonding temperature is desirably in the range of about 520 °C or more and less than about 540 °C. Thus, the bonded body of the present invention in which the ceramic plate and the MMC plate are bonded via the bonding layer can be obtained.

Example

[0027] The present invention will be described more specifically by the following examples. However, the present invention is not limited to the following examples.

[0028] Examples 1 to 9 (1) Production of ceramic plate As a ceramic plate, a disk-shaped aluminum oxide sintered body (thickness: 5 mm, diameter: 300 mm) with an ESC electrode embedded therein was fabricated as follows. First, disk-shaped first and second alumina green sheets were prepared. An ESC electrode was formed on one surface of the first green sheet by screen printing, while a heater electrode was formed on one surface of the second green sheet by screen printing. Next, another alumina green sheet (hereinafter referred to as the third green sheet) was laminated on the surface of the first green sheet on which the ESC electrode was formed, and then the second green sheet was laminated thereon such that the heater electrode was in contact with the third green sheet. The obtained laminate was fired by a hot press method to obtain a ceramic sintered body in which the ESC electrode and the heater electrode were embedded. The shape and thickness were adjusted by performing grinding, blasting, etc. on both surfaces of the obtained ceramic sintered body, and a flat electrostatic chuck was obtained as the ceramic plate. The specific manufacturing conditions of this electrostatic chuck were set with reference to the conditions described in Japanese Patent Laid-Open No. 2006-196864.

[0029] (2) Fabrication of MMC Plate As an MMC plate, a plate containing Si, C, and Ti (SiSiCTi plate) was fabricated as follows. First, as raw materials, a SiC raw material (a commercially available product with a purity of 97% or more and an average particle size of 15.5 μm), a metallic Si raw material (a commercially available product with a purity of 97% or more and an average particle size of 9.0 μm), and a metallic Ti raw material (a commercially available product with a purity of 99.5% or more and an average particle size of 31.1 μm) were prepared. The SiC raw material, the metallic Si raw material, and the metallic Ti raw material were weighed so as to have a blending ratio of SiC: 49.5 mass%, Si: 20.0 mass%, and Ti: 30.5 mass%, and were put into a nylon pot together with isopropyl alcohol as a solvent, and wet-mixed for 4 hours using a nylon ball with an iron core having a diameter of 10 mm. The obtained slurry was taken out, dried at 110°C in a nitrogen stream, and then passed through a 30-mesh sieve to obtain a formulated powder. The formulated powder was... 200 kgf / cm 2Uniaxially press-molded at the pressure of 2 to produce a disk-shaped compact with a diameter of 50 mm and a thickness of about 17 mm, which was then placed in a graphite mold for firing. An MMC plate was obtained by hot press-firing the disk-shaped compact. This hot press-firing was carried out by maintaining at a firing temperature (maximum temperature) of 1400 °C for 4 hours while applying a press pressure of 200 kgf / cm

[0030] For the surface of the MMC plate thus prepared where the bonding layer was to be bonded, the arithmetic mean roughness Ra conforming to JIS B 0601-2001 was measured using a stylus-type surface roughness measuring instrument. The results were as shown in Table 1.

[0031] (3) Preparation of the bonding layer To obtain the bonding layer, an Si- and Mg-containing Al alloy sheet with a thickness of 0.12 mm (alloy composition: Si: 10 wt%, Mg: 1 wt%, balance: Al and unavoidable impurities) was prepared.

[0032] (4) Cleaning process For each of the ceramic plate and the MMC plate, the following cleaning processes (i) to (vi) were carried out in sequence, while for the Si- and Mg-containing Al alloy sheet, only the following cleaning processes (i), (ii), and (iv) were carried out in sequence. <Cleaning process> (i) Ultrasonic cleaning using acetone (not carried out in Example 9) (ii) Ultrasonic cleaning using isopropyl alcohol (IPA) (not carried out in Example 9) (iii) Running water cleaning using pure water (iv) Blowing with 2 N gas (v) Drying at 120 °C for 10 minutes

[0033] At this time, the total cleaning time of (i) ultrasonic cleaning using acetone and (ii) ultrasonic cleaning using isopropyl alcohol (IPA), that is, the ultrasonic cleaning time with organic solvents, was varied for each experimental example as shown in Table 1. Therefore, as described above, for Example 9, the ultrasonic cleaning in (i) and (ii) was not carried out.

[0034] (5) Thermocompression bonding Thermocompression bonding was performed as follows using a cleaned ceramic plate, an MMC plate, and a bonding sheet. That is, a bonding sheet was sandwiched as a bonding layer between the ceramic plate and the MMC plate, and thermocompression bonding was performed at a pressure of 20 MPa in a vacuum while heating to 530 °C (a temperature lower than the liquidus temperature of the Si- and Mg-containing Al alloy and not lower than a temperature about 30 °C lower than the solidus temperature), thereby joining the ceramic plate, the bonding sheet (bonding layer), and the MMC plate to each other. Thus, a joined body in which the ceramic plate and the MMC plate were joined via the bonding layer was obtained.

[0035] (6) Evaluation of the joined body The following evaluations were performed on the fabricated joined body.

[0036] <Obtaining an elemental mapping image by EPMA> After cutting out a cross-section of the obtained joined body and performing mirror polishing, flat ion milling with Ar ions was carried out to obtain an observation cross-section. A 75 μm × 75 μm region including the ceramic plate 12, the bonding interface 20, and the bonding layer 16 in the obtained observation cross-section was observed with an SEM (scanning electron microscope), and elemental analysis of the region was performed by EPMA (manufactured by JEOL Ltd.) under measurement conditions of an acceleration voltage of 15 kV to obtain elemental mapping images of Si, C, Ti, O, Mg, and Al. FIGS. 3A and 3B show an SEM image (Compo image) of a cross-section including the ceramic plate 12, the bonding interface 20, and the bonding layer 16 in the joined body of Example 7 and elemental mapping images of various elements in the corresponding region. As a result, as shown in Table 1 and FIGS. 3A and 3B, in the joined bodies of Examples 1 to 7, a Mg-containing layer 24 containing Mg at a higher concentration than its surroundings was observed at the bonding interface 20, and it was also confirmed that this Mg-containing layer 24 further contained Al and O. On the other hand, in the joined bodies of Examples 8 and 9 (comparative examples), such a Mg-containing layer was not observed.

[0037] In addition, for a 75 μm × 75 μm region including the bonding layer 16, the bonding interface 22, and the bonding interface 22 between the MMC plate 14 in the obtained observation cross-section, SEM observation and EPMA elemental analysis were also performed in the same manner as above. Figures 4A and 4B show SEM images (Compo images) of a cross-section including the bonding layer 16, the bonding interface 22, and the MMC plate 14 in the bonded body of Example 7, and various element mapping images of the corresponding regions. As a result, in all of the bonded bodies of Examples 1 to 9, as shown in Figures 4A and 4B, TiC particles (see the black particles in the figure), TiSi 2 a microstructure having a matrix phase (see the gray portion in the figure) and SiC particles (see the white particles in the figure) was observed. In addition, in the bonded bodies of Examples 1 to 7, it was also confirmed that Mg and Al were diffused in the SiSiCTi constituting the MMC plate 14.

[0038] Furthermore, for a wider cross-sectional region of 300 μm × 300 μm including the bonding layer 16, the bonding interface 22, and the bonding interface 22 between the MMC plate 14, SEM observation and EPMA elemental analysis were performed in the same manner as above, except that the magnification was lowered and the concentration scale was reduced. Figures 5A and 5B show a reduced-concentration-scale version of the SEM image (Compo image) of a cross-section including the bonding layer 16, the bonding interface 22, and the MMC plate 14 in the bonded body of Example 7, and various element mapping images of the corresponding regions. As a result, in the bonded bodies of Examples 1 to 9, the presence of an Al diffusion layer 26 and a Mg diffusion layer 28 in which Al and Mg derived from the bonding layer 16 were diffused over the depth direction of the MMC plate 14 from the bonding interface 22 were confirmed within the MMC plate 14. The depth D of the Al diffusion layer 26 from the bonding interface 22 Al and the depth D of the Mg diffusion layer 28 from the bonding interface 22 Mg were measured, and the values as shown in Table 1 were obtained.

[0039] <Weight ratio of Al:Mg:O in the Mg-containing layer> Semi-quantitative values of each element for each pixel corresponding to 0.24 μm × 0.24 μm were calculated from the EPMA measurement results, and the weight ratio calculation was performed from the average value of 300 pixels to calculate the weight ratio of Al:Mg:O.

[0040] <Bonding strength> From the obtained bonded body, a long sample was cut out so that the bonding layer was located at the center in the longitudinal direction, and the surface of the sample was ground to prepare a test piece with dimensions of 1.5 mm × 2.0 mm × 20 mm. For this test piece, a four-point bending test was performed under the conditions of a lower span of 15 mm, an upper span of 5 mm, and a crosshead speed of 0.5 mm / min with the bonding interface as the center, and the obtained maximum bending stress (MPa) was taken as the bonding strength. The results were as shown in Table 1.

[0041]

Table 1

Claims

1. A ceramic plate and an MMC plate made of a metal matrix composite material (MMC) and disposed opposite one side of the ceramic plate; a bonding layer provided between the ceramic plate and the MMC plate for bonding the ceramic plate and the MMC plate, the bonding layer containing Al as a main component and Si and Mg as subcomponents; wherein the bonding interface between the ceramic plate and the bonding layer includes a Mg-containing layer. zygote.

2. The joint body according to claim 1 , wherein the Mg-containing layer further comprises Al and O.

3. 3. The joined body according to claim 2, wherein the weight ratio of Al:Mg:O in the Mg-containing layer is 1:0.01-0.50:0.001-0.

100.

4. The joined body according to claim 1 or 2, wherein the Mg-containing layer has a thickness of 1 to 10 μm.

5. The joined body according to any one of claims 1 to 3, wherein the ceramic plate, the joining layer and the MMC plate are joined by thermocompression welding.

6. The joint body according to any one of claims 1 to 3, wherein the metal matrix composite (MMC) contains Si, C and Ti.

7. The MMC plate is disposed at a predetermined depth D from the bonding interface between the bonding layer and the MMC plate. Ａｌ The joined body according to any one of claims 1 to 3, further comprising an Al diffusion layer in which Al originating from the joining layer is diffused throughout the joined body.

8. The MMC plate is disposed at a predetermined depth D from the bonding interface between the bonding layer and the MMC plate. Ｍｇ The joined body according to claim 7 , further comprising an Mg diffusion layer in which Mg derived from the joining layer is diffused throughout the joined body.

9. The depth D of the Al diffusion layer Ａｌ is the depth D of the Mg diffusion layer Ｍｇ That is, D Ａｌ >D Ｍｇ The composite according to claim 8 , which satisfies the above formula.

10. The joint body according to any one of claims 1 to 3, wherein the surface of the MMC plate at the joining interface side has an arithmetic mean roughness Ra of 0.01 to 1.0 µm.

11. The bonded body according to any one of claims 1 to 3, which exhibits a bond strength of 200 MPa or more in a four-point bending test.

12. 4. The joined body according to claim 1, wherein the ceramic plate contains aluminum oxide and / or aluminum nitride and has an internal electrode embedded therein.

13. A ceramic plate and an MMC plate provided opposite one side of the ceramic plate and made of a metal matrix composite material (MMC) containing Si, C, and Ti; a bonding layer provided between the ceramic plate and the MMC plate for bonding the ceramic plate and the MMC plate, the bonding layer containing Al as a main component and Si and Mg as subcomponents; and the MMC plate is provided with a predetermined depth D from a bonding interface between the bonding layer and the MMC plate. Ａｌ The Al diffusion layer has an Al diffusion layer in which Al originating from the bonding layer is diffused over a depth D Ａｌ The bonded body, wherein the thickness is 40 μm or more.

14. The MMC plate is disposed at a predetermined depth D from the bonding interface between the bonding layer and the MMC plate. Ｍｇ The joined body according to claim 13 , further comprising an Mg diffusion layer in which Mg derived from the joining layer is diffused throughout the joined body.

15. The depth D of the Al diffusion layer Ａｌ is the depth D of the Mg diffusion layer Ｍｇ That is, D Ａｌ >D Ｍｇ The composite according to claim 14 ,

16. The joined body according to any one of claims 13 to 15, wherein the ceramic plate contains aluminum oxide and / or aluminum nitride and has an internal electrode embedded therein.

17. The joint body according to any one of claims 13 to 15, wherein the ceramic plate, the joint layer and the MMC plate are joined by thermocompression bonding.

18. The joint body according to any one of claims 13 to 15, wherein the surface of the MMC plate at the joining interface side has an arithmetic mean roughness Ra of 0.01 to 1.0 μm.

19. The bonded body according to any one of claims 13 to 15, which exhibits a bond strength of 200 MPa or more in a four-point bending test.

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