Joint, manufacturing method thereof, and electrode-embedded member

Abstract

To provide a joined body capable of suppressing erosion and contamination of a joined face, strong in joint strength, and thick in the thickness of a metal member, a production method of the same, and an electrode-embedded member.SOLUTION: A joint body 10 includes a ceramic member 20 of Al2O3 as a main constituent, and a metal member 30 comprising a high melting point metal having a melting point of 2,000°C or higher, where the ceramic member 20 is joined to at least one principal plane 32 of the metal member 30, the metal member 30 has a maximum thickness of 1 mm or more in a direction vertical to one principal plane 32 of the metal member 30, and the metal member 30 has an average thickness of a carbide layer of 40 μm or less, the carbide layer containing a carbide of the high-melting point metal in the vicinity of a joint interface of the ceramic member 20 and the metal member 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bonded body, a method for producing the same, and an electrode-embedding member. [Background technology]

[0002] Al2O3 components used in semiconductor manufacturing equipment are sometimes joined to metal components to add various functions.

[0003] Patent Document 1 discloses a bonded body in which a ceramic member and a metal member are bonded together, with the aim of sufficiently increasing the strength of the bonded body. The bonded body is formed by bonding a terminal made of a high-melting point metal or Ti having a Ni coating, Au coating, or Ni-Au coating (with a Ni base) to a recess provided in a plate-shaped alumina or aluminum nitride ceramic member via a bonding layer. The bonding layer contains Au, Ge, Ag, Cu, and Ti, and is in contact with at least a portion (here, the entirety) of the side surface and the bottom surface of the recess. The bonding layer is rich in Ti at the bonding interface with the ceramic member, and the bonded body has a porosity (porosity) of 0.1 to 15% when the bonded body is cut in the thickness direction of the bonded body.

[0004] Furthermore, Patent Document 2 discloses a sputtering target-backing plate joint in which a sputtering target (TG) and a backing plate (BP) are joined using brazing material in which the outer periphery of the brazing material between the sputtering target (TG) and the backing plate (BP) is covered with a wire-shaped material having a melting point of 600 to 3500°C and a circular, elliptical or rectangular axial cross-sectional shape, with the aim of providing a technology for effectively suppressing the occurrence of arcing and particle generation that occurs when brazing material is used to join the sputtering target and the backing plate and that is caused by the brazing material being exposed between the sputtering target and the backing plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-91676 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-37621 Summary of the Invention [Problem to be solved by the invention]

[0006] Al2O3 ceramics used in semiconductor manufacturing processes are sometimes integrated with high-melting-point metals used in heat sinks, etc. To do this, the high-melting-point metal needs to be thicker than a certain amount, but such a structure cannot be achieved by providing a bonding layer as in Patent Document 1.

[0007] Furthermore, in the method of integrating via a brazing material as described in Patent Document 2, although it is possible to increase the size, there are concerns about erosion of the brazing material that is the bonding layer and contamination from the bonding layer.

[0008] Therefore, there has been a demand for an Al2O3-high melting point metal joint that is a joint between an Al2O3 ceramic and a thick high melting point metal and that reduces the risk of contamination or erosion from the joint material.

[0009] The present invention has been made in view of the above circumstances, and aims to provide a bonded body that can suppress erosion and contamination of the bonding surface, has high bonding strength, and has thick metal members, a method for manufacturing the same, and an electrode-embedded member. [Means for solving the problem]

[0010] (1) In order to achieve the above object, the present invention provides a joined body including a ceramic member mainly composed of Al2O3 and a metal member made of a high-melting-point metal having a melting point of 2000°C or higher, wherein the ceramic member is joined to at least one main surface of the metal member, the metal member has a maximum thickness of 1 mm or more in a direction perpendicular to the one main surface of the metal member, and the metal member has a carbide layer containing carbide of the high-melting-point metal near the joining interface between the ceramic member and the metal member, the average thickness of which is 40 μm or less.

[0011] In this way, by reducing the average thickness of the carbide layer containing carbides of high-melting-point metals near the bonding interface between the Al2O3 ceramics and the metal component, the bonding strength between the Al2O3 ceramics and the metal component can be increased, resulting in a bonded body that suppresses erosion and contamination of the bonding surface. Furthermore, the thicker metal component can be used in a variety of applications, such as using the metal component as a heat sink or improving the strength and dimensional accuracy of the bonded body.

[0012] (2) In the joined body of the present invention, the carbide layer of the metal member has an average thickness of 5 μm or less.

[0013] In this way, by reducing the average thickness of the carbide layer of the metal member, the bonding strength between the Al2O3 ceramic and the metal member increases, and the reliability of the bonded body increases.

[0014] (3) In the joined body of the present invention, the metal member contains 1 wt % or less of a second metal oxide.

[0015] In this way, when the metal member contains 1 wt % or less of the second metal oxide, the bonding strength between the Al2O3 ceramic and the metal member is increased, and the reliability of the bonded body is improved.

[0016] (4) In the joined body of the present invention, the metal member has a through-hole penetrating in the thickness direction or a groove on one or the other of its main surfaces.

[0017] In this way, by providing the metal member with a through-hole penetrating in the thickness direction or a groove on one or the other of the main surfaces, the range of uses of the bonded body is further expanded.

[0018] (5) The joined body of the present invention is characterized in that a ceramic member is further joined to the other main surface of the metal member opposite to the one main surface of the metal member.

[0019] In this way, by bonding Al2O3 ceramics to both main surfaces of the metal component, the internal stress of the bonded body is balanced, improving the reliability of the bonded body and further expanding the range of uses for the bonded body.

[0020] (6) The electrode-embedding member of the present invention is characterized by comprising the joined body according to any one of (1) to (4) above and an electrode embedded in a ceramic member of the joined body.

[0021] Since the composition of Al2O3 can be easily adjusted over a wide range, electrode-embedded components, which are Al2O3 ceramics and metal component joints with electrodes embedded in the Al2O3 ceramics, can be used as heater modules suitable for various conditions such as process temperature and heat transfer.

[0022] (7) A method for producing a joined body of the present invention is a method for producing a joined body of ceramic members mainly composed of Al2O3 and metal members made of a high-melting-point metal having a melting point of 2000°C or higher, the method including the steps of: preparing a granulated powder by granulating an Al2O3 raw powder or a powder obtained by adding a metal oxide raw powder to the Al2O3 raw powder; stacking the granulated powder or a compact formed from the granulated powder, and the high-melting-point metal plate having a thickness of 1 mm or more on a carbon mold so that one main surface of the high-melting-point metal plate is perpendicular to the stacking direction; inserting a carbon punch into the carbon mold to form a stack; and uniaxially pressurizing and sintering the stack, wherein the uniaxially pressurizing and sintering step is controlled so that an average thickness of a carbidized layer containing a carbide of the high-melting-point metal in the metal member near the joining interface between the ceramic member and the metal member is 40 μm or less.

[0023] This results in a bonded assembly of Al2O3 ceramics and metal members made of high-melting-point metals with high bonding strength and reduced erosion and contamination on the bonding surfaces. The thick metal member can be used for a variety of purposes, such as using the metal member as a heat sink or increasing the strength and dimensional accuracy of the Al2O3 ceramics.

[0024] (8) In the method for producing a joined body of the present invention, the plate-shaped high-melting-point metal may have a through-hole penetrating through the plate in the thickness direction or a groove on one or the other of its main surfaces.

[0025] In this way, by using a plate-shaped high-melting point metal having through holes penetrating in the thickness direction or grooves on one or the other main surface, the high-melting point metal, which is difficult to process, can be processed in advance, and shapes for various structures can be produced more easily than if it were processed after firing, further expanding the uses of the joined body. [Effects of the Invention]

[0026] According to the present invention, a bonded body can be obtained in which erosion and contamination of the bonding surface between a ceramic member mainly composed of Al2O3 and a metal member made of a high-melting-point metal are suppressed. In addition, the thick metal member can be used in various applications, such as as a heat sink or to increase the strength and dimensional accuracy of the ceramic member. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic cross-sectional view showing an example of a bonded body according to an embodiment of the present invention. [Figure 2] FIG. 10 is a schematic cross-sectional view showing a modified example of the bonded body according to the embodiment of the present invention. [Figure 3] 1 is a schematic cross-sectional view showing an example of an electrode-embedded member according to an embodiment of the present invention. [Figure 4] 1(a) to 1(e) are cross-sectional views each showing a schematic diagram of a step in the manufacturing process of a manufacturing method according to an embodiment of the present invention. [Figure 5] 1(a) to 1(e) are cross-sectional views each showing a schematic diagram of a step in the manufacturing process of a manufacturing method according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic enlarged cross-sectional view of the cross section of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0028] Next, an embodiment of the present invention will be described with reference to the drawings. To facilitate understanding of the description, the same reference numerals are used to designate the same components in the drawings, and duplicated descriptions will be omitted. Note that in the configuration diagrams, the size of each component is shown conceptually and does not necessarily represent the actual dimensional ratio.

[0029] [Embodiment] [Construction of the zygote] First, a bonded body according to an embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an example of a bonded body according to an embodiment of the present invention. A bonded body 10 according to an embodiment of the present invention is formed by bonding a ceramic member 20 primarily composed of Al2O3 and a metal member 30 composed of a high-melting-point metal. A ceramic member primarily composed of Al2O3 refers to a member containing 90 wt% or more of Al2O3. A metal member composed of a high-melting-point metal refers to a member having a purity of 99 wt% or more, such as molybdenum (Mo), tungsten (W), or tantalum (Ta), which has a melting point of 2000°C or higher. This suppresses deformation of the metal member 30 even at temperatures during uniaxial pressure sintering. At the same time, a high-melting-point metal oxide with a relatively high melting point of 900°C or higher is formed at the interface between the Al2O3 and the metal member 30, thereby suppressing deformation at the bonding interface between the Al2O3 and the metal member 30.

[0030] In the joined body 10, the ceramic member 20 is joined to at least one main surface of the metal member 30. The metal member 30 preferably has a maximum diameter that is 50% or more of the maximum diameter of the ceramic member 20. The ceramic member 20 is preferably joined to the entire surface of one main surface of the metal member 30. These characteristics allow the metal member 30 to be applied in various forms according to various uses. The ceramic member 20 is preferably joined directly to one main surface of the metal member 30 without any other member interposed therebetween. This is because the joining strength may be reduced if another member is interposed therebetween.

[0031] The ceramic member 20 may include a second phase made of a metal oxide. When the ceramic member 20 includes a second phase made of a metal oxide, the metal constituting the metal oxide of the second phase is preferably one or more selected from transition metal oxides and rare earth oxides. The metal oxide constituting the second phase may be a sintering aid for a ceramic member mainly composed of Al2O3. In this case, the metal oxide constituting the second phase may be added in a necessary amount as a sintering aid for the ceramic member. For example, when Si is added as a sintering aid, it may be added in an amount of 0.1 wt% to 10 wt% in terms of SiO2. Alternatively, the ceramic member 20 may be composed only of Al2O3.

[0032] The metal member 30 has a maximum thickness of 1 mm or more in a direction perpendicular to one main surface 32 of the metal member 30. In this way, the metal member 30 having a large thickness can be used in a variety of applications, such as as a heat sink, a heat spreader, or a component incorporating a refrigerant channel or a gas channel, or for improving the strength and dimensional accuracy of the ceramic member 20. The one main surface 32 of the metal member 30 is the bonding surface with the ceramic member 20. The metal member 30 having a large thickness means that the maximum thickness in a direction perpendicular to the one main surface 32 of the metal member 30 is 1 mm or more. If the maximum thickness of the metal member is less than 1 mm, the effect of improving dimensional accuracy will not be fully achieved, and therefore it is preferable that the maximum thickness be 1 mm or more.

[0033] The maximum thickness of the metal member 30 in the direction perpendicular to one main surface 32 is preferably set to a thickness according to the intended use. Considering that there has not been a joined body of metal members 30 with a large thickness like that of the present invention, depending on the intended use, the thickness is preferably 2 mm or more, more preferably 3 mm or more, and even more preferably 4 mm or more.

[0034] The metal member 30 may have a carbide layer 38 containing a carbide of a high-melting-point metal near the bonding interface between the ceramic member 20 and the metal member 30. When the metal member 30 has the carbide layer 38, the average thickness of the carbide layer 38 is 40 μm or less. Because the carbide layer 38 containing a carbide of a high-melting-point metal is an embrittlement layer, reducing the average thickness of the carbide layer 38 near the bonding interface between the ceramic member 20 and the metal member 30 can strengthen the bonding strength between the Al2O3 ceramic and the metal member, resulting in a bonded body that suppresses erosion and contamination of the bonding surface. The average thickness of the carbide layer 38 of the metal member 30 is preferably 5 μm or less. In this way, reducing the average thickness of the carbide layer 38 containing a carbide of a high-melting-point metal strengthens the bonding strength between the Al2O3 ceramic and the metal member, thereby improving the reliability of the bonded body. The vicinity of the bonding interface will be described later.

[0035] The carbide layer 38 containing the carbide of the high-melting-point metal is affected by the components of Al2O3 that form the ceramic member 20, and also by the presence or absence of a metal oxide that forms a second phase and the amount of the metal oxide added. Therefore, the C component in the carbide layer of the high-melting-point metal is presumed to be residual carbon in the granulated powder due to the addition of the metal oxide or contamination from the environment.

[0036] The metal member 30 preferably has through-holes penetrating in the thickness direction or grooves on one main surface 32 or the other main surface 34. By providing the metal member 30 with through-holes penetrating in the thickness direction or grooves on one main surface 32 or the other main surface 34 in this way, the applications of the joined body 10 are further expanded. For example, the metal member 30 can be used as a member having a refrigerant flow path or a gas flow path.

[0037] The oxygen concentration at the bonding interface between the ceramic member 20 and the metal member 30 is preferably higher than the oxygen concentration inside the ceramic member 20. Furthermore, when the ceramic member 20 contains a second phase made of a metal oxide, the concentration of the metal constituting the second phase of the ceramic member 20 and the oxygen concentration at the bonding interface between the ceramic member 20 and the metal member 30 are preferably higher than the concentration of the metal and the oxygen concentration inside the ceramic member 20, respectively. In this way, when the oxygen concentration at the bonding interface between the ceramic member 20 mainly composed of Al2O3 and the metal member 30 made of a high-melting-point metal is higher than the oxygen concentration inside the ceramic member 20, or when the concentration of the metal constituting the second phase and the oxygen concentration are higher than the concentration of the metal and the oxygen concentration inside the ceramic member 20, respectively, the ceramic member 20 and the metal member 30 are bonded together via these, and a bonded body in which erosion and contamination of the bonding surface are suppressed can be obtained.

[0038] The reason for the increase in oxygen concentration near the bonding interface is thought to be that the natural oxide film formed on the surface of the refractory metal reacts with the refractory metal, producing refractory metal oxides with melting points of 900°C or higher during firing, some of which become molten and diffuse into the ceramic component.

[0039] The bonding interface between the ceramic member 20 and the metal member 30 refers to the interface where the concentration of the metal element that primarily constitutes the metal member 30 drops sharply in cross-sectional elemental mapping using EDX or EPMA. The interior of the ceramic member 20 refers to a region at least 1 mm away from the bonding interface, perpendicular to the line approximating the bonding interface. When the ceramic member 20 contains a second phase made of a metal oxide, this region may also be referred to as a region where the concentration of the metal that constitutes the second phase of the ceramic member 20 is uniform. The vicinity of the bonding interface refers to a region within 100 μm perpendicular to the line approximating the bonding interface. The carbide layer 38 of the high-melting-point metal is entirely contained in the vicinity of the bonding interface.

[0040] The changes in the concentrations of metal, carbon, and oxygen present in the ceramic member 20, the metal member 30, or their bonded interface can be determined by comparing the intensity (count number) of characteristic X-rays in the relevant areas using an EPMA. This allows the relative differences in the concentrations of metal, carbon, and oxygen near and inside the interface to be evaluated.

[0041] The presence of the refractory metal carbide layer 38 can be confirmed by cross-sectional elemental mapping using EDX or EPMA, and its thickness can be measured by cross-sectional SEM or optical microscope observation. The thickness of the refractory metal carbide layer 38 can be measured, for example, by drawing ten lines at 10 μm intervals perpendicular to a line approximating the bond interface on a 1000x SEM image and averaging the lengths of the line segments that overlap with the confirmed carbide layer. This average value is used as the average thickness of the refractory metal carbide layer 38 in that field of view. To obtain an overall average value, it is preferable to further average the average values ​​obtained for three or more fields of view. Here, if the carbide layer 38 is so thin that it is difficult to confirm it in the SEM image, it is evaluated as being at least 2 μm or less, so that its dimensions can be measured.

[0042] The metal member 30 may not have a carbide layer 38 of a high-melting point metal near the bonding interface between the ceramic member 20 and the metal member 30. "No carbide layer 38 of a high-melting point metal near the bonding interface" means that, when the bonding interface is approximated by a straight line in elemental mapping of a cross section by EDX or EPMA, no C component is detected within an area of ​​100 μm perpendicular to the straight line.

[0043] It is preferable that the ceramic member 20 further contains a Group 4 metal, and that the Group 4 metal is diffused in the metal member 30. In this way, when the ceramic member 20 contains a Group 4 metal and the Group 4 metal is diffused in the metal member 30, the bonding strength between the ceramic member 20 and the metal member 30 is increased, and the reliability of the bonded body 10 is improved. The Group 4 metal is preferably one or more selected from Ti and Hf, and more preferably Ti.

[0044] The metal member 30 preferably contains 1 wt% or less of the second metal oxide. When the metal member 30 contains 1 wt% or less of the second metal oxide, the bonding strength between the ceramic member 20 and the metal member 30 is increased, and the reliability of the bonded body 10 is improved. The metal constituting the second metal oxide is preferably one or more selected from Y, Ce, and Ca, and more preferably Y or Ce. When the ceramic member 20 contains a second phase made of a metal oxide, the metal constituting the second metal oxide may be the same as the metal constituting the metal oxide of the second phase of the ceramic member 20. These metal oxide components already contained in the metal member 30 can increase the metal and oxygen concentrations at the bonding interface, thereby increasing the bonding strength.

[0045] 2 is a schematic cross-sectional view showing a modified example of a bonded body according to an embodiment of the present invention. As shown in FIG. 2, it is preferable that a ceramic member 20 is further bonded to the other main surface 34 of the metal member 30, opposite to the one main surface 32. By bonding the ceramic members 20 to both main surfaces of the metal member 30 in this manner, the internal stress of the bonded body is balanced, improving the reliability of the bonded body and further expanding the range of uses of the bonded body 10. Furthermore, by sandwiching the plate-shaped high-melting-point metal (metal member 30) between the ceramic members 20, warping of the bonded body 10 can be suppressed, and a bonded body 10 with high dimensional accuracy can be produced.

[0046] [Configuration of electrode embedding material] Next, an electrode-embedded member according to an embodiment of the present invention will be described. Fig. 3 is a schematic cross-sectional view showing an example of an electrode-embedded member according to an embodiment of the present invention. An electrode-embedded member 50 according to an embodiment of the present invention includes a bonded body 10 and an electrode 40 embedded in a ceramic member 20 of the bonded body 10.

[0047] The joined body 10 is the joined body 10 described above. The electrode 40 is embedded in the ceramic member 20 of the joined body 10. The electrode 40 may have various shapes, such as a mesh shape or a foil shape, and may be made of various materials, such as molybdenum or tungsten. The electrode 40 can be used as a heater electrode.

[0048] The electrode-embedding member 50 may be provided with terminal holes and terminals (not shown).

[0049] The bonded body and electrode-embedded member of the present invention are members that suppress erosion and contamination at the joining surface of a ceramic member primarily composed of Al2O3 and a metal member made of a high-melting-point metal. Furthermore, the bonded body and electrode-embedded member of the present invention have a thick metal member, making them suitable for a variety of applications, such as using the metal member as a heat sink, heat spreader, or member incorporating a refrigerant or gas flow path, or for improving the strength and dimensional accuracy of ceramic members. Furthermore, because the composition of Al2O3 can be easily adjusted over a wide range, the bonded body and electrode-embedded member of the present invention can be used as members suitable for a variety of conditions, such as process temperature and heat transfer.

[0050] [Method of manufacturing the bonded body and the electrode-embedded member] Next, a method for manufacturing the bonded body 10 configured as described above will be described. Figures 4(a) to 4(e) are cross-sectional views each showing a schematic diagram of one stage of the manufacturing process according to the embodiment of the present invention.

[0051] First, granulated powder 22 is prepared by granulating Al2O3 raw powder or powder obtained by adding metal oxide raw powder to Al2O3 raw powder. The Al2O3 raw powder is preferably highly pure, preferably 96% or more, more preferably 98% or more. The average particle size of the Al2O3 powder is preferably 0.1 μm or more and 1.0 μm or less, more preferably 0.3 μm or more and 0.8 μm or less. When SiO2, for example, is used as the metal oxide raw powder, 0.1 wt% to 10 wt% of SiO2 is added to the Al2O3 raw powder, and a PVA-based binder, dispersant, and solvent are added to prepare a slurry, which is then granulated using a spray dryer or the like to produce granulated powder 22.

[0052] Next, a plate-shaped high-melting point metal 36 having a thickness of 1 mm or more is prepared, and the granulated powder 22 or a compact formed from the granulated powder, and the plate-shaped high-melting point metal 36 having a thickness of 1 mm or more are stacked in a bottomed carbon mold 60 (molding mold) so that one main surface of the plate-shaped high-melting point metal 36 is perpendicular to the stacking direction.

[0053] As another example of laminating compacts, one or more compacts are produced using the obtained granulated powder 22. As a method for forming the compacts, known methods such as uniaxial pressing or cold isostatic pressing (CIP) may be used. Note that the method for forming the compacts is not limited to pressure forming, and for example, green sheet lamination or slip casting may also be applied.

[0054] When producing electrode-embedded member 50, when stacking granulated powder 22, granulated powder 22 is pre-pressed, electrode 40 is arranged, and granulated powder 22 is further added and pre-pressed, or compacts are stacked, electrode 40 is arranged, and further compacts are stacked, whereby electrode 40 is embedded in the portion that will become ceramic member 20 after sintering.

[0055] Next, a carbon punch 70 is inserted into the carbon mold 60 to form the laminate 12. The laminate 12 may be a two-layer structure consisting of a layer of granulated powder 22 or a compact that will become the ceramic member 20 after sintering and a plate-shaped high-melting-point metal 36 that will become the metal member 30 after sintering, or a three-layer structure in which the plate-shaped high-melting-point metal 36 is sandwiched between layers of granulated powder 22 or a compact. The side surfaces in the stacking direction may have portions where the plate-shaped high-melting-point metal 36 is exposed, or the plate-shaped high-melting-point metal 36 may be covered with the granulated powder 22 or the compact. FIG. 4 shows a case in which the plate-shaped high-melting-point metal 36 is covered with the granulated powder 22 and is fabricated into three layers.

[0056] Next, the laminate 12 is uniaxially pressurized and fired to produce the bonded body 10. The firing conditions are, for example, a temperature of 1500°C to 2000°C, a pressure of 1 MPa or more, and a holding time of 0.1 to 10 hours.

[0057] At this time, the uniaxial pressure firing process is controlled so that the average thickness of the carbide layer 38 containing the carbide of the high-melting point metal near the bonding interface between the ceramic member 20 and the metal member 30 in the metal member 30 is 40 μm or less. Since the carbide layer 38 of the high-melting point metal tends to thicken more quickly as the amount of additives contained in the ceramic member 20 increases, it is preferable to shorten the firing time and lower the firing temperature. On the other hand, in order to sinter the ceramic member 20, it is necessary to fire the ceramic member 20 at a predetermined temperature or higher for a predetermined time depending on the type and amount of additives contained in the ceramic member 20. Therefore, the firing time and firing temperature are adjusted depending on the type and amount of additives contained in the ceramic member 20.

[0058] After firing, a process for processing the plate-shaped high-melting-point metal 36 into a predetermined shape may be performed. At this time, if the side surfaces of the plate-shaped high-melting-point metal 36 in the stacking direction are covered with ceramic members, processing may be performed to expose the plate-shaped high-melting-point metal 36. Also, if the plate-shaped high-melting-point metal 36 is a three-layer structure sandwiched between layers of ceramic members 20, processing may be performed to remove some of the ceramic members 20 or all of one of the ceramic members 20. Also, a process for processing the shape of the plate-shaped high-melting-point metal 36 may be performed. At this time, processing is performed so that the maximum thickness of the plate-shaped high-melting-point metal 36 in the direction perpendicular to one main surface 32 is not less than 1 mm.

[0059] In addition, in the case of using the electrode-embedding member 50, a step of exposing a part of the electrode 40 and a step of connecting a terminal to the electrode 40 may be provided.

[0060] The method for producing and laminating a compact may include a step of degreasing the compact to produce a degreased body and a step of calcining the degreased body to produce a calcined body. In this case, for example, the degreasing temperature is preferably 400°C or higher and 800°C or lower, and the degreasing time is preferably 1 hour or higher and 120 hours or lower. The degreasing atmosphere is preferably an air atmosphere or a nitrogen atmosphere, and more preferably an air atmosphere. Furthermore, for example, the calcination temperature is preferably 1200°C or higher and 1700°C or lower, and the calcination time is preferably 0.5 hours or higher and 12 hours or lower. The calcination atmosphere is preferably a nitrogen or inert gas atmosphere, but may also be a vacuum atmosphere.

[0061] Furthermore, the plate-shaped high-melting-point metal 36 preferably has through-holes penetrating in the thickness direction or grooves on one main surface 32 or the other main surface 34. By using the plate-shaped high-melting-point metal 36 having through-holes penetrating in the thickness direction or grooves on one main surface 32 or the other main surface 34 in this way, the difficult-to-process high-melting-point metal can be processed in advance, and shapes for various structures can be produced more easily than by processing after firing, further expanding the uses of the joined body 10.

[0062] 5(a) to 5(e) are cross-sectional views each showing a schematic diagram of one stage of the manufacturing process of the manufacturing method according to the embodiment of the present invention. Fig. 5 shows an example of the manufacturing method using a plate-shaped high-melting-point metal 36 having through-holes penetrating in the thickness direction and grooves on the other main surface 34. Only the differences from the above manufacturing method will be explained.

[0063] In the step of preparing plate-shaped high-melting-point metal 36 having a thickness of 1 mm or more, through-holes penetrating the plate-shaped high-melting-point metal 36 in the thickness direction or grooves on one main surface 32 or the other main surface 34 are machined in accordance with the design of the joined body 10. Furthermore, in the step of forming the laminate 12, it is preferable to fill the through-holes or grooves of the plate-shaped high-melting-point metal 36 formed by machining with granulated powder 22 or a compact formed from the granulated powder. By filling the through-holes or grooves with granulated powder or the like and firing the resulting ceramic member in this manner, the risk of defects occurring in the fired ceramic member is reduced. In addition to granulated powder 22 or a compact formed from the granulated powder, a calcined or fired body of these may also be filled.

[0064] After firing, the plate-shaped high-melting-point metal 36 is machined into a predetermined shape. At this time, by machining the ceramic-filled areas of the through-holes or grooves in the plate-shaped high-melting-point metal 36, the burden of post-processing after firing can be reduced. The through-holes are used, for example, as holes for later attachment of power supply terminals for electrode extraction, holes for supplying or suctioning gas, and holes for lift pins for mounting the substrate. The grooves are used, for example, as parts of coolant flow paths or gas flow paths.

[0065] By using this method, it is possible to manufacture a bonded body or a buried electrode member in which corrosion and contamination of the bonding surfaces of a ceramic member mainly composed of Al2O3 and a metal member made of a high-melting-point metal are suppressed.

[0066] [Example] (Preparation of junction) Example 1 5 wt% SiO2 and 1 wt% each of CaO, MgO, and TiO2 were added to the Al2O3 raw powder, and a binder (PVA), dispersant, and solvent were added to prepare a slurry, which was then granulated using a spray dryer. In addition, plate-shaped Mo with a diameter of 50 mm and a thickness of 5 mm was prepared as a plate-shaped high-melting-point metal to be used as the metal component.

[0067] Next, the granulated powder was filled into a bottomed carbon mold and press-molded with a carbon punch to produce a compact with a diameter of 80 mm and a thickness of 10 mm. Mo was then placed on the compact. Next, the carbon mold was further filled with the granulated powder to embed the Mo. At this time, the granulated powder was filled and molded with the carbon punch so that the thickness from the top surface of the Mo was 10 mm.

[0068] Then, with the carbon punch inserted into the carbon mold, uniaxial hot press sintering was performed for 2 hours at a temperature of 1500°C, a pressure of 4 MPa, and a N2 atmosphere. This resulted in a 50 mm diameter metal member made of Mo, a high-melting-point metal, embedded inside an 80 mm diameter Al2O3 sintered body. In this way, the bonded body of Example 1 was produced. After that, multiple test pieces of Example 1 measuring 3 mm x 4 mm x 19 mm were cut out with the long sides aligned in the stacking direction.

[0069] Example 2 A joint body of Example 2 was produced using the same process and conditions as in Example 1, except that the high melting point metal was replaced with an alloy in which 0.4 wt % of Y2O3 was added to Mo.

[0070] Example 3 A joined body of Example 3 was produced using the same process and conditions as in Example 1, except that the high-melting-point metal was replaced with W.

[0071] Example 4 A joined body of Example 4 was produced using the same process and conditions as in Example 1, except that the granulated powder was changed to only Al2O3 raw material powder.

[0072] Example 5 A bonded body of Example 5 was produced using the same steps and conditions as Example 1, except that the firing time was changed to 5 hours.

[0073] Example 6 A joined body of Example 6 was produced using the same steps and conditions as in Example 1, except that the granulated powder of Example 1 was changed to AlO raw material powder to which 10 wt % of SiO was added, and the resulting mixture was uniaxially hot-press sintered at a temperature of 1500°C under a pressure of 4 MPa in a N atmosphere for 10 hours.

[0074] (Bonding strength measurement) The bond strength of the bonded bodies was measured using a three-point bending strength test in accordance with JIS R1601 2008 (room temperature bending strength test method for fine ceramics). The span was 10 mm, and the bond surface was placed at the center in the longitudinal direction, with the knife edge aligned with the bond surface. Five test pieces were prepared for each sample, and the average of the five measurements was used as the bond strength value for each sample.

[0075] (Measurement results) In Example 1, the bonding strength was 160 MPa, which was found to be sufficient. In Example 2, the bonding strength was 175 MPa, which was higher than that of the sample in Example 1. In Example 3, the bonding strength was 165 MPa, which was found to be sufficient. In Example 4, the bonding strength was 240 MPa, which was higher than that of the sample in Example 1. In Example 5, the bonding strength was 140 MPa, which was lower than that of the sample in Example 1, but it can be used as a bonded body. In Example 6, the bonding strength was 90 MPa, which is usable as a bonded body, but the strength may be insufficient depending on the application.

[0076] (Elemental analysis) Next, elemental analysis of the sample cut perpendicular to the lamination direction was performed using an EPMA to map the results. It was found that oxygen and the metal added to the ceramic member were present within the ceramic member (Al2O3), but were present in greater amounts at the bonding interface between the ceramic member and the metal member made of a high-melting-point metal. This confirms that the concentration of the metal added to the ceramic member and the oxygen concentration at the bonding interface between the ceramic member and the metal member are greater than the metal and oxygen concentrations, respectively, within the ceramic member.

[0077] Fig. 6 is a schematic enlarged cross-sectional view of Example 1. The cross-section of the same field of view was previously subjected to elemental analysis using an EPMA, and the results were compared with the color tone of the SEM image. As a result, it was found that the vicinity of the bonding interface of the bonded body was layered in the following order from top to bottom: an Al2O3 ceramic layer, an oxygen-rich Al2O3 ceramic layer, a Mo layer which is a high-melting-point metal, a carbide layer 38 containing Mo carbide, and another Mo layer, as shown in Fig. 6. It was also found that the cross-sections of other Examples had similar structures, although the thickness of each layer was different.

[0078] The Al2O3 ceramic layer and the oxygen-rich Al2O3 ceramic layer showed no difference in color tone in the SEM images. Furthermore, the oxygen-rich Al2O3 ceramic layers of Examples 1 and 2 contained not only O but also Si in large amounts compared to the Al2O3 ceramic layers located relatively far from the bonding interface. The oxygen-rich Al2O3 ceramic layer of Example 4 contained a large amount of O. The Al2O3 ceramic layer and the oxygen-rich Al2O3 ceramic layer were not distinguishable by a clear standard, as they were portions of the ceramic members with relatively different amounts of oxygen, etc.

[0079] The refractory metal carbide layer 38 was formed at a position slightly away from the bonded interface. The carbon required for carbidization of the refractory metal is thought to be derived from the raw materials or from the environment, but the reason why such a layer was formed at a position slightly away from the bonded interface is unknown.

[0080] (Measurement of the thickness of the carbide layer) The average thickness of the carbide layer of the high-melting-point metal was measured using 1000x SEM images, and the results were 15 μm for Example 1, 10 μm for Example 2, 12 μm for Example 3, 3 μm for Example 4, 25 μm for Example 5, and 40 μm for Example 6. This confirmed that the thinner the carbide layer of the high-melting-point metal, the higher the bonding strength tends to be.

[0081] The bonded body of the present invention is believed to have high bond strength because the average thickness of the carbide layer containing refractory metal carbide formed at the bonded interface between the ceramic and metal members can be sufficiently thin. Furthermore, the presence of a high concentration of oxygen at the bonded interface between the ceramic and metal members is likely to result in chemical bonding between the refractory metal and Al2O3 via oxygen. When the ceramic member contains a metal oxide constituting a second phase, not only oxygen but also the metal constituting the second phase of the ceramic member is present at a high concentration at the bonded interface between the ceramic and metal members. This may also contribute to the bond strength. However, the addition of the metal oxide constituting the second phase to the raw materials in such a bonded body promotes carbidization during uniaxial pressing, resulting in a thick average thickness of the refractory metal carbide layer, which is believed to result in a low bond strength. Furthermore, in the manufacturing method of the present invention, the recrystallization temperature of the high-melting point metal is exceeded during sintering, and therefore, it is presumed that the high-melting point metal at the joining surface undergoes plastic deformation, penetrating into the irregularities on the surface of the Al2O3 sintered compact and exerting an anchor effect, thereby obtaining even higher joining strength.

[0082] Example 7 The high-melting-point metal used as the metal member of Example 1 was a Mo plate with a diameter of 60 mm and a thickness of 10 mm, which had four 6 mm through-holes (PCD 40 mm, evenly spaced). Furthermore, grooves with a width of 5 mm and a depth of 5 mm were formed perpendicularly through the center of the metal member. The metal member was then placed on a compact with a diameter of 80 mm. Granulated powder was then filled into the through-holes and grooves of the metal member, and the granulated powder was further added to embed the Mo to a depth of 10 mm from the top surface of the Mo. A joined body of Example 7 was fabricated using the same process and conditions.

[0083] After firing the bonded body of Example 7, holes penetrating the through-holes in the Mo plate and grooves reaching the grooves in the Mo plate were formed in the ceramic member. Both were easier to form than machining the Mo plate after firing the bonded body. It was confirmed that when it is necessary to form such a structure in the bonded body, it is preferable to pre-process the plate-shaped high-melting-point metal before firing.

[0084] Example 8 (Production of electrode-embedded member) In Example 7, a heater electrode was embedded in an Al2O3 sintered body (ceramic member) located on a high-melting-point metal in the manufacturing method of Example 1, to produce a heater module that can be used in high-temperature processes.

[0085] The granulated powder prepared was the same as that prepared in Example 1. Furthermore, a plate-shaped Mo having a diameter of Φ300 mm and a thickness of 8 mm was prepared as a plate-shaped high-melting point metal to be used as the metal member.

[0086] First, a heater laminate was produced. The granulated powder was filled into a bottomed carbon mold and press-molded with a carbon punch to produce a compact with a diameter of 320 mm and a thickness of 8 mm. Next, a heater electrode was placed on the mold. The heater electrode was a Mo mesh (wire diameter 0.1 mm, mesh size #50, plain weave) cut into a predetermined pattern to match the resistance value of the heater electrode. Next, the granulated powder was further filled into the carbon mold to embed the heater electrode, producing a heater laminate. At this time, the granulated powder was filled and molded with a carbon punch so that the thickness from the top surface of the heater electrode was 8 mm.

[0087] Next, plate-shaped Mo was placed on the heater laminate. The carbon mold on which the Mo was placed was further filled with granulated powder to embed the Mo. At this time, the plate-shaped Mo was formed with a carbon punch so that the thickness from the top surface was 8 mm, and a laminate was produced. In this way, a heater laminate and a laminate in which plate-shaped Mo were stacked were produced.

[0088] Then, with the carbon punch inserted into the carbon mold, uniaxial hot press firing was performed at a temperature of 1500°C, a pressure of 4 MPa, and a N2 atmosphere for 4 hours. After firing, the outer shape (Φ300 mm x 18 mm) was processed. Drilling terminal holes for connecting the electrodes to an external power supply, connecting the terminals, and fabricating the necessary insulating structure were all performed simultaneously during processing after firing. In this way, the electrode-embedded member of Example 8 was produced.

[0089] (evaluation) The fabricated heater module could be heated to 400°C by applying electricity to the heater electrodes from an external power source.

[0090] From the above, it was confirmed that the bonded body and electrode-embedded member of the present invention can suppress erosion and contamination of the bonding surface, have high bonding strength, and have thick metal members. It was also confirmed that the manufacturing method of the present invention can manufacture such a bonded body or electrode-embedded member.

[0091] The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and equivalents are included within the spirit and scope of the present invention. Furthermore, the structure, shape, number, position, size, etc. of the components shown in each drawing are for the convenience of explanation and may be changed as appropriate. [Explanation of symbols]

[0092] 10 zygote 12 Laminate 20 Ceramic materials 22 Granulated powder 30 Metallic parts 32 One main surface 34 Other main surface 36 Plate-shaped high-melting-point metal 38 Carbidization layer 40 electrodes 50 Electrode embedding member 60 Carbon type 70 Carbon Punch

Claims

1. Al ２ O ３ A joined body of a ceramic member mainly composed of a high-melting-point metal having a melting point of 2000°C or higher, the ceramic member is bonded to at least one main surface of the metal member, The metal member has a maximum thickness of 1 mm or more in a direction perpendicular to one main surface of the metal member, The joined body is characterized in that the metal member has a carbide layer containing carbide of the high-melting point metal in the vicinity of the joining interface between the ceramic member and the metal member, the average thickness of which is 40 μm or less.

2. 2. The joined body according to claim 1, wherein the carbide layer of the metal member has an average thickness of 5 μm or less.

3. 3. The joined body according to claim 1, wherein the metal member contains 1 wt % or less of the second metal oxide.

4. 4. The joined body according to claim 1, wherein the metal member has a through-hole penetrating in a thickness direction or a groove on one or the other of its main surfaces.

5. 5. The joined body according to claim 1, wherein a ceramic member is further joined to the other main surface of the metal member opposite to the one main surface of the metal member.

6. The bonded body according to any one of claims 1 to 4, an electrode embedded in the ceramic member of the joined body;

7. Al ２ O ３ A method for manufacturing a joined body of ceramic members mainly composed of a high-melting-point metal having a melting point of 2000°C or higher, Al ２ O ３ Raw material powder or Al ２ O ３ a step of preparing granulated powder by granulating a powder obtained by adding a metal oxide raw material powder to a raw material powder; stacking the granulated powder or a compact formed from the granulated powder, and the plate-shaped high-melting point metal having a thickness of 1 mm or more on a carbon mold so that one main surface of the plate-shaped high-melting point metal is perpendicular to a stacking direction; inserting a carbon punch into the carbon mold to form a laminate; and uniaxially pressing and firing the laminate, a carbide layer containing a carbide of the high-melting point metal in the vicinity of the bonding interface between the ceramic member and the metal member having an average thickness of 40 μm or less in the uniaxial pressure sintering step.

8. 8. The method for manufacturing a bonded body according to claim 7, wherein the plate-shaped high-melting-point metal has a through-hole penetrating in the thickness direction or a groove on one or the other of its main surfaces.

Images