Electrode embedding member

Abstract

To provide an electrode embedding member that can suppress the intrusion of oxygen between a connecting member and a ceramic sintered body, suppress the deterioration of the connecting member, and extend the product life compared to conventional products.SOLUTION: An electrode embedding member 100 includes: a substrate 110 formed in a flat plate shape from a ceramic sintered body whose main component is AlN; an electrode 120 embedded in the substrate 110; a connecting member 130 made of W or Mo and electrically connected to the electrode 120 and embedded in the substrate 110; and a bonding-strengthening layer 140 formed on an interface between a lower surface 132 of the connecting member 130 and the ceramic sintered body, wherein the bonding-strengthening layer 140 is made of a main phase 142 containing W or Mo, a first subphase 144 containing Al, and a second subphase 146 containing Y.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrode-embedding member. [Background technology]

[0002] BACKGROUND ART Conventionally, electrode-embedded members such as susceptors, electrostatic chucks, and ceramic heaters, in which electrodes are embedded in a ceramic sintered body, have been proposed as components for semiconductor manufacturing equipment.

[0003] Patent Document 1 discloses a technology for a holding device that holds an object on the surface of a ceramic member, the holding device comprising: a ceramic member formed from a ceramic sintered body whose main component is aluminum nitride; a metallic heating resistor disposed inside the ceramic member; a conductive power supply connection member that contacts the heating resistor; and a conductive power supply terminal that is electrically connected to the power supply connection member, with the aim of suppressing variations in the heat generation amount of a heating resistor resulting from variations in the resistance value of the power supply connection member. At least a portion of the surface of the power supply connection member, excluding the contact surface with the heating resistor and the connection surface with the power supply terminal, is covered with a coating layer formed from a nitride containing at least one of Al, Ti, Zr, V, Ta, and Nb. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6867550 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional electrode-embedding members, oxygen can penetrate through the terminal holes into the interface between the embedded connecting member and the ceramic sintered body, causing the connecting member to deteriorate. When the electrode-embedding member is used under these conditions, the difference in physical properties between the connecting member and the ceramic sintered body increases, causing the connecting member to no longer function as an electrode-embedding member, and the end of its product life. Therefore, there is a need for an electrode-embedding member that suppresses this deterioration of the connecting member and has a longer product life than conventional products, as well as a method for manufacturing such an electrode-embedding member.

[0006] In the technology described in Patent Document 1, the surface of the power supply connection member is covered with a coating layer, which can prevent the power supply connection member from reacting with impurities during firing and forming an altered layer on the surface of the power supply connection member. However, Patent Document 1 does not take into consideration the prevention of oxidation of the connection member when the electrode embedding member is used, and it is unclear whether oxidation of the connection member can be prevented when the electrode embedding member is used.

[0007] The inventors discovered that by forming a bonding-strengthening layer at the interface between the connecting member and the ceramic sintered body, it is possible to suppress the intrusion of oxygen between the connecting member and the ceramic sintered body, and thereby suppress deterioration of the connecting member, and thus completed the present invention.

[0008] In other words, the present invention has been made in consideration of the above circumstances, and aims to provide an electrode-embedding member that can suppress the intrusion of oxygen between the connecting member and the ceramic sintered body, suppress deterioration of the connecting member, and extend the product life compared to conventional products. [Means for solving the problem]

[0009] (1) In order to achieve the above object, the electrode-embedding member of the present invention has the following features: That is, the electrode-embedded member of an application example of the present invention is an electrode-embedded member comprising: a base formed in a flat plate shape from a ceramic sintered body whose main component is AlN; an electrode embedded in the base; a connection member made of W or Mo and electrically connected to the electrode and embedded in the base; and a bonding-strengthening layer formed on the interface between the lower surface of the connection member and the ceramic sintered body, wherein the bonding-strengthening layer is characterized by comprising a main phase containing W or Mo, a first subphase containing Al, and a second subphase containing Y.

[0010] In this way, the bonding-strengthening layer on the underside of the connecting member creates an anchoring effect between the connecting member and the ceramic sintered body, improving adhesion, preventing oxygen from penetrating between the connecting member and the ceramic sintered body, and preventing deterioration of the connecting member. As a result, the product life of the electrode-embedding member can be extended compared to conventional products.

[0011] (2) Furthermore, the electrode-embedded member of the application example (1) above is characterized in that, in a cross section perpendicular to the substrate mounting surface of the base, the area ratio of the first subphase and the second subphase in the region of the bonding reinforcement layer facing the base is larger than the area ratio of the first subphase and the second subphase in the region of the bonding reinforcement layer facing the connecting member.

[0012] This increases the anchoring effect between the connection member and the ceramic sintered body, further suppressing oxygen intrusion through the terminal hole and further suppressing deterioration of the connection member, thereby extending the product life of the electrode-embedding member compared to conventional products.

[0013] (3) Furthermore, the electrode-embedded member according to the application example of (1) or (2) above is characterized in that, in a cross section perpendicular to the substrate mounting surface of the base, the first subphase and the second subphase are dispersed in the bonding-reinforcing layer in a granular form.

[0014] This increases the anchoring effect between the connection member and the ceramic sintered body, further suppressing oxygen intrusion through the terminal hole and further suppressing deterioration of the connection member, thereby extending the product life of the electrode-embedding member compared to conventional products.

[0015] (4) In the electrode-embedding member according to any one of the application examples (1) to (3) above, the bonding-reinforcing layer is formed on the top surface or side surface of the connection member.

[0016] This increases the anchoring effect between the connection member and the ceramic sintered body, further suppressing oxygen penetration through the terminal hole and further suppressing deterioration of the connection member. As a result, deterioration can be suppressed, and the product life of the electrode-embedding member can be made even longer than conventional products. [Effects of the Invention]

[0017] According to the present invention, it is possible to prevent oxygen from penetrating between the connection member and the ceramic sintered body, thereby preventing deterioration of the connection member, thereby extending the product life of the electrode-embedding member compared to conventional products. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view showing an example of an electrode-embedded member according to an embodiment of the present invention. [Figure 2] FIG. 2 is a partially enlarged view of the electrode-embedded member of FIG. [Figure 3] 1 is a 500x SEM image of a cross section of the electrode-embedding member of Example 1, taken perpendicular to the substrate-mounting surface. [Figure 4] 1 is an SEM image at 5000 magnifications of a cross section perpendicular to the substrate mounting surface of the electrode-embedding member of Example 1. [Figure 5] 1 is a flowchart illustrating an example of a method for manufacturing an electrode-embedded member according to an embodiment of the present invention. [Figure 6] 1(a) to 1(c) are cross-sectional views each showing a schematic diagram of one stage in the manufacturing process of an electrode-embedded member according to an embodiment of the present invention. [Figure 7] 1(a) to 1(c) are cross-sectional views each showing a schematic diagram of one stage in the manufacturing process of an electrode-embedded member according to an embodiment of the present invention. [Figure 8] 3A to 3C are cross-sectional views schematically illustrating a step in the manufacturing process of an electrode-embedded member according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] 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.

[0020] [Embodiment] [Configuration of electrode embedding material] An electrode-embedded member according to an embodiment of the present invention will be described with reference to Figs. 1 and 2. Fig. 1 is a cross-sectional view showing an example of an electrode-embedded member according to an embodiment of the present invention. Fig. 2 is a partially enlarged view of the electrode-embedded member of Fig. 1. An electrode-embedded member 100 according to an embodiment of the present invention includes a base 110, an electrode 120, a connection member 130, and a bonding-reinforcing layer 140. The electrode-embedded member 100 is applicable to RF bases, ceramic heaters, electrostatic chucks, etc.

[0021] The base 110 is formed into a flat plate shape from a ceramic sintered body whose main component is AlN. One of the main surfaces of the base 110 has a substrate mounting surface 112 on which a substrate is mounted. The shape of the base 110 may be a substantially circular plate, or may be a polygonal plate, elliptical plate, or any of a variety of other shapes.

[0022] A ceramic sintered body primarily composed of AlN means that it contains 90 wt% or more of AlN. AlN ceramics often contain sintering aids made from oxides of 2a and 3a group elements to adjust their physical properties, such as increasing thermal conductivity. Generally, increasing the amount of sintering aid increases thermal conductivity, but adding more than a certain amount is known to cause a decrease in thermal conductivity. Therefore, it is desirable to keep the content of sintering aids made from oxides of 2a and 3a group elements below 10 wt%. Examples of additives for 2a group elements include Mg, Ca, Sr, and Ba, while examples of additives for 3a group elements include Y, La, Sm, and Ce.

[0023] A ceramic sintered body containing AlN as its main component has high thermal conductivity and excellent heat resistance and plasma resistance, and physical properties such as thermal conductivity can be easily adjusted by adjusting the type and amount of sintering aid added. Therefore, by forming the base 110 from a ceramic sintered body containing AlN as its main component, it is possible to configure a base 110 with adjustable thermal conductivity and excellent heat resistance and plasma resistance.

[0024] The electrode 120 is embedded in the substrate 110. The electrode 120 is used, for example, as a high-frequency electrode. Electrodes used for other purposes, such as a heater electrode or an electrostatic attraction electrode, may also be embedded. The electrode 120 may have various shapes, such as a mesh shape or a foil shape, depending on the design of the electrode-embedding member 100. The electrode 120 is preferably made of Mo, W, or an alloy containing these.

[0025] The base 110 may include a plurality of electrodes. In this case, the bonding-reinforcing layer 140 of the present invention, which will be described later, may be formed on a connecting member electrically connected to at least one of the electrodes. The bonding-reinforcing layer 140 of the present invention may be formed on a plurality of connecting members.

[0026] The connection member 130 is embedded in the base 110 and electrically connected to the electrode 120. This allows electricity to be supplied to the electrode 120 via the connection member 130. The connection member 130 is made of W or Mo. The connection member 130 being made of W or Mo means that the purity of W or Mo is 50 wt % or more.

[0027] The shape of the connecting member 130 may be various, such as a flat, approximately circular plate, a polygonal plate, or an elliptical plate, or may be a truncated cone whose radial dimension varies along the thickness direction. Among these, the shape of the connecting member 130 is preferably approximately circular. When the connecting member 130 is formed in an approximately circular plate shape, its diameter φ is preferably 5 mm or more and 10 mm or less. The thickness of the connecting member 130 is preferably 0.1 mm or more and 0.5 mm or less. If the thickness of the connecting member 130 is less than 0.1 mm, there is a risk of breakage when forming the terminal hole 152 for connecting the terminal 150. If the thickness of the connecting member 130 is more than 0.5 mm, there is a risk of cracks occurring in the base 110 due to differences in shrinkage rate during firing and thermal expansion rate during use between the connecting member 130 and the ceramic of the base 110.

[0028] The bond-strengthening layer 140 is formed at the interface between the lower surface 132 of the connection member 130 and the ceramic sintered body. The bond-strengthening layer 140 is composed of a main phase 142 containing W or Mo, a first subphase 144 containing Al, and a second subphase 146 containing Y. This prevents oxygen that has entered the terminal hole 152 from entering between the lower surface 132 of the connection member 130 and the ceramic sintered body, thereby preventing deterioration of the connection member 130. As a result, the product life of the electrode-embedding member 100 can be extended compared to conventional products. Furthermore, the reliability of the electrical connection via the connection member 130 can be further improved.

[0029] The interface between the lower surface 132 of the connecting member 130 and the ceramic sintered body is the portion where the lower surface 132 of the connecting member 130 and the ceramic sintered body come into contact. It is believed that the reason oxygen intrusion between the lower surface 132 of the connecting member 130 and the ceramic sintered body is suppressed is because the bonding-strengthening layer 140 is formed at the interface between the lower surface 132 of the connecting member 130 and the ceramic sintered body, improving adhesion between the connecting member 130 and the ceramic sintered body. The main phase 142 containing W or Mo is a phase containing 50 wt% or more of W or Mo as a main component. The first subphase 144 containing Al is a phase containing 50 wt% or more of Al as a main component. The second subphase 146 containing Y is a phase containing 50 wt% or more of Y as a main component. The thickness of the bonding-strengthening layer 140 is preferably 5 μm or more and 500 μm or less.

[0030] Fig. 3 is a scanning electron microscope (SEM) image at 500x magnification of a cross section perpendicular to the substrate mounting surface 112 of the electrode-embedding member 100 of Example 1, which will be described later. Fig. 4 is an SEM image at 5000x magnification of a cross section perpendicular to the substrate mounting surface 112 of the base 110 of the electrode-embedding member 100 of Example 1. Fig. 4 shows an enlarged view of a partial region of the same cross section as in Fig. 3. The black dots in the bond-reinforcing layer 140 in the SEM image of Fig. 3 indicate the first subphase 144 and the second subphase 146. The gray background indicates the main phase 142. The fact that the main phase 142, the first subphase 144, or the second subphase 146 each contain W, Mo, Al, or Y as a main component can be confirmed from the results of EDX (Energy Dispersive X-ray Spectroscopy) or WDX (Wavelength Dispersive X-ray Spectroscopy) on the same screen as the SEM image.

[0031] 3 , in a cross section perpendicular to the substrate mounting surface 112 of the base 110, the area ratio of the first subphase 144 to the second subphase 146 in the region of the bond-reinforcing layer 140 facing the base 110 is preferably larger than the area ratio of the first subphase 144 to the second subphase 146 in the region of the bond-reinforcing layer 140 facing the connecting member 130. This enhances the anchor effect between the connecting member 130 and the ceramic sintered body, further suppresses oxygen intrusion through the terminal holes 152, and further suppresses deterioration of the connecting member 130. Furthermore, a larger area ratio of the first subphase 144 to the second subphase 146 in the region facing the base 110 improves the wettability between the base 110 and the bond-reinforcing layer 140 during firing, thereby improving adhesion. Furthermore, when the area ratio of the first subphase 144 and the second subphase 146 in the region on the connecting member 130 side becomes relatively small, the difference in CTE between the region on the connecting member 130 side of the bond-reinforcing layer 140 and the connecting member 130 becomes closer, which is expected to have the effect of suppressing stress and distortion during firing. As a result, the product life of the electrode-embedding member 100 can be made even longer than conventional products.

[0032] The boundary between the region of the bond-reinforcing layer 140 on the substrate 110 side and the region on the connecting member 130 side is a line that bisects the thickness of the bond-reinforcing layer 140 with respect to the lower surface 132 of the connecting member 130. The area ratio of the first subphase 144 and the second subphase 146 in the region of the bond-reinforcing layer 140 on the substrate 110 side is the ratio of the area of ​​the first subphase 144 and the second subphase 146 present in the region of the bond-reinforcing layer 140 on the substrate 110 side to the area of ​​the region of the bond-reinforcing layer 140 on the substrate 110 side. The area ratio is similarly calculated for the first subphase 144 and the second subphase 146 in the region of the bond-reinforcing layer 140 on the connecting member 130 side. Image analysis software such as Winroof or Imagej may be used to calculate the area ratio.

[0033] 3, in a cross section perpendicular to the substrate mounting surface 112 of the base 110, the first subphase 144 and the second subphase 146 are preferably dispersed in the form of particles within the bond-reinforcing layer 140. This enhances the anchoring effect between the connection member 130 and the ceramic sintered body, further suppresses oxygen intrusion through the terminal hole 152, and further suppresses deterioration of the connection member 130. As a result, the product life of the electrode-embedding member 100 can be extended even further compared to conventional products.

[0034] Note that a bond-strengthening layer 140 may be formed on the surface of the connecting member 130 other than the interface between the lower surface 132 of the connecting member 130 and the ceramic sintered body. For example, the bond-strengthening layer 140 may be formed on the upper or side surface of the connecting member 130. This increases the anchoring effect between the connecting member 130 and the ceramic sintered body, further suppresses oxygen intrusion through the terminal hole 152, and further suppresses deterioration of the connecting member 130. As a result, the product life of the electrode-embedding member 100 can be extended even further than conventional products. Furthermore, manufacturing the connecting member 130 so that the bond-strengthening layer 140 is formed on the lower and upper surfaces of the connecting member 130 facilitates the electrode preparation process, which will be described later, and makes it easy to manufacture a member with a longer functional life.

[0035] The present invention is only required to suppress the intrusion of oxygen from between the connecting member 130 and the ceramic sintered body. Therefore, the formation of a bond-strengthening layer 140 at the interface between the lower surface 132 of a connecting member 130 made of W or Mo and the ceramic sintered body includes all combinations of a connecting member 130 made of W and a bond-strengthening layer 140 containing a W-containing main phase 142; a connecting member 130 made of W and a bond-strengthening layer 140 containing a Mo-containing main phase 142; a connecting member 130 made of Mo and a bond-strengthening layer 140 containing a Mo-containing main phase 142; and a connecting member 130 made of Mo and a bond-strengthening layer 140 containing a W-containing main phase 142. However, it is preferable that the main components of the main phases 142 of the connecting member 130 and the bond-strengthening layer 140 are the same. This is because the adhesion between the connecting member 130 and the bond-strengthening layer 140 is further improved when the main components are the same.

[0036] The terminal 150 is inserted into the terminal hole 152 and electrically connected to the connection member 130. This allows power to be supplied to the electrode 120. The terminal 150 can be made of Ni or the like. The terminal 150 is brazed to the connection member 130 with Au solder or the like. A buffer member 154 made of W, Mo, Kovar or the like may be provided between the connection member 130 and the terminal 150. A plurality of buffer members 154 may be provided.

[0037] The terminal holes 152 are drilled from the lower surface of the base 110. The terminal holes 152 are drilled to a depth that exposes the connection members 130.

[0038] The electrode-embedding member 100 of the present invention can suppress the intrusion of oxygen between the connecting member 130 and the ceramic sintered body, thereby suppressing deterioration of the connecting member 130. As a result, the product life of the electrode-embedding member 100 can be made longer than that of conventional products. In particular, since the influence on the insulating layer 114 of the base 110 on the upper surface of the electrode 120 can be suppressed, the reliability of the electrode-embedding member 100 can be increased.

[0039] [Method for manufacturing electrode-embedded members] Next, a method for manufacturing the electrode-embedded member according to the present embodiment will be described. The electrode-embedded member according to the present embodiment is manufactured, for example, by a molded body hot pressing method described below. Note that the manufacturing method is not limited to this method, and may be, for example, a powder hot pressing method or a conventional green sheet lamination method. The powder hot pressing method is a method in which ceramic raw material powder and predetermined heating resistors and electrodes are alternately stacked to embed the heating resistors and electrodes inside the ceramic, and then the resultant is uniaxial hot press fired.

[0040] Fig. 5 is a flowchart showing a method for manufacturing an electrode-embedded member according to an embodiment of the present invention. As shown in Fig. 5, the method for manufacturing an electrode-embedded member according to a first embodiment of the present invention includes a compact preparation step (STEP 1), an electrode etc. preparation step (STEP 2), a paste application step (STEP 3), a precursor formation step (STEP 4), and a firing step (STEP 5).

[0041] Figures 6(a) to 6(c), 7(a) to 7(c), and 8 are cross-sectional views each showing a stage in the manufacturing process of the electrode-embedded member according to this embodiment. Figures 6 to 8 show a stage in the manufacturing process using a molded body hot pressing method. Figures 6 to 8 show the case of manufacturing the electrode-embedded member of Figure 1.

[0042] In the compact preparation step, STEP 1, multiple compacts are prepared from ceramics containing AlN as the main component. The compacts in the compact preparation step, STEP 1, include ceramic compacts in the compact hot pressing method, degreased ceramics, calcined ceramics, green sheets in the green sheet lamination method, extrusion compacts, and compacts in the roll compaction and powder hot pressing methods.

[0043] In FIG. 6, the ceramic molded bodies 11 and 12 are divided into two components, but they may be three or more depending on the design of the electrode-embedded member. For example, a slurry is prepared by adding additives such as a binder, plasticizer, and dispersant to a raw powder of AlN ceramic and mixing them. Next, the granulated powder is granulated by a method such as spray drying. The granulated powder is then pressure-molded to form a plurality of ceramic molded bodies 11 and 12. If necessary, a sintering aid powder may be added to the raw ceramic powder.

[0044] The raw material powder of the AlN ceramic is preferably highly pure, preferably 96% or more, more preferably 98% or more, and preferably has an average particle size of 0.1 μm or more and 1.0 μm or less.

[0045] The mixing method may be either wet or dry, and a mixer such as a ball mill or a vibration mill may be used. Furthermore, known methods such as uniaxial pressing or cold isostatic pressing (CIP) may be used as the molding method. The method for forming the ceramic molded body is not limited to pressure molding; for example, green sheet lamination or slip casting may also be used, and the ceramic molded body can be manufactured by appropriately degreasing or further calcining the resulting body. After molding, the multiple ceramic molded bodies 11 and 12 may be machined to shape the molded body.

[0046] Next, the plurality of ceramic molded bodies 11, 12 are degreased at a predetermined temperature or higher for a predetermined time or longer to produce a plurality of ceramic degreased bodies 21, 22. The ceramic molded bodies 11, 12 are heat treated at a temperature of, for example, 400°C or higher and 800°C or lower to become the ceramic degreased bodies 21, 22. The degreasing time is preferably 1 hour or longer and 120 hours or shorter. For degreasing, An atmospheric furnace or a nitrogen atmosphere furnace can be used, but an atmospheric furnace is preferable for removing unnecessary components of the binder. As shown in FIG. 6(c), a recess 50 having a shape matching the shape of the electrode 120 and the connecting member 130 may be formed on one main surface of the ceramic degreased body 22 (the bonding surface with another ceramic degreased body 21). The recess 50 may be formed on one of the ceramic degreased bodies 21, or on both. Machining may be performed on the ceramic molded body before degreasing. The electrode-embedded member 100 may be produced without the degreasing step.

[0047] In the electrode preparation step 2, the electrodes 120, the connecting members 130 made of W or Mo, and the paste 40 containing W or Mo are prepared. The electrode preparation step 2 can be performed in any order relative to the compact formation step 1. The electrodes 120 are formed from a foil, thin plate, wire, mesh, or porous body made of molybdenum or tungsten, or the like, by filling with paste or printing.

[0048] The connecting member 130 is made of W or Mo. The connecting member 130 is prepared by processing it into a shape and thickness according to the design of the electrode-embedding member 100. The paste 40 containing W or Mo is a paste obtained by mixing W or Mo powder with a binder. The W or Mo powder preferably has an average particle diameter D50 of 1 μm or more and 10 μm or less. The paste 40 containing W or Mo preferably contains W or Mo powder in a proportion of 50 wt% or more and 90 wt% or less. Any binder may be used, but ethyl cellulose, for example, can be used. The paste 40 containing W or Mo is applied to a predetermined surface of the connecting member 130, and by undergoing a firing step STEP 5 described below, the bonding-strengthening layer 140 is formed. The bonding-strengthening layer 140 is made of a main phase 142 containing W or Mo, a first subphase 144 containing Al, and a second subphase 146 containing Y.

[0049] In the paste application step STEP 3, paste 40 is applied to a predetermined area on the lower surface 132 of the connecting member 130. The thickness of the paste 40 is preferably 10 μm or more and 500 μm or less. The predetermined area refers to at least the surface of the lower surface 132 of the connecting member 130 that comes into direct contact with the ceramic degreased body, excluding the area where the terminal hole 152 is drilled. As a result, a bonding-strengthening layer 140 is formed in the area where the paste 40 containing W or Mo is applied.

[0050] The reason why the range in which the terminal holes 152 are drilled may be excluded from the predetermined range is that the bond-strengthening layer 140 in that range does not contribute to suppressing oxygen penetration when the terminal holes 152 are drilled. In other words, the bond-strengthening layer 140 in that range does not contribute to improving the adhesion between the connection member 130 and the ceramic sintered body. Furthermore, when drilling the terminal holes 152, the bond-strengthening layer 140 in that range may also be removed. On the other hand, since it is easier to apply the paste 40 to the entire lower surface 132 of the connection member 130, the paste 40 may be applied to the entire lower surface 132 of the connection member 130. Furthermore, since it is easier to apply the paste 40 to the entire side surface of the connection member 130, the paste 40 may be applied to the entire side surface of the connection member 130. As a result, the bond-strengthening layer 140 is also formed on the side surface to which the paste 40 containing W or Mo is applied.

[0051] The paste 40 containing W or Mo can also be used to improve the reliability of the electrical connection between the connection member 130 and the electrode 120. Therefore, the paste 40 may be applied to the upper surface of the connection member 130. Therefore, the paste 40 may be applied to the entire surface of the connection member 130, including the upper and lower surfaces, or the upper and side surfaces. This allows one type of paste 40 containing W or Mo to fulfill multiple roles, thereby reducing costs compared to applying different pastes to the upper and lower surfaces. The paste 40 containing W or Mo may also be applied to the connection member 130 by dipping. This simplifies the process and further reduces costs. That is, the paste application step (STEP 3) also includes application by dipping.

[0052] In the precursor-forming step STEP 4, the prepared electrode 120, the connecting member 130 coated with the paste 40, and multiple green bodies are combined to form a flat-plate-shaped electrode-embedding member precursor 60 in which the electrode 120 and the connecting member 130 are embedded. In FIG. 6, ceramic degreased bodies 21 and 22 are used as the multiple green bodies. The electrode-embedding member precursor 60 may also be formed by powder hot pressing in the precursor-forming step STEP 4. In this case, the green bodies formed in the precursor-forming step STEP 4 are combined with the prepared electrode 120 and the connecting member 130 coated with the paste 40, and then combined with a green body formed by adding raw material powder to form the flat-plate-shaped electrode-embedding member precursor 60 in which the electrode 120 and the connecting member 130 are embedded.

[0053] In the firing step (STEP 5), the formed electrode-embedding member precursor 60 is sintered by uniaxial pressure in a direction perpendicular to one of the main surfaces of the electrode-embedding member precursor 60 to produce an electrode-embedding member 100. The pressure is preferably 1 MPa or more. The firing temperature is preferably a predetermined maximum temperature of 1800°C or more and 2000°C or less. The heating rate during firing is preferably adjusted from 1500°C to the maximum temperature at a rate of 0.5°C / min to 10°C / min. This is believed to cause some of the AlN and sintering aid components in the AlN sintered body to diffuse into the paste 40 and become the first subphase 144 and the second subphase 146. The firing time is preferably 1 hour or more and 12 hours or less. The firing atmosphere is, for example, a nitrogen or inert gas atmosphere, but may also be a vacuum atmosphere. As a result, the plurality of compacts are sintered to form a ceramic sintered body, which is integrated together to obtain the electrode-embedded member 100 in which the electrodes 120 and the connecting members 130 are embedded.

[0054] Alternatively, a component that will become the first subphase 144 containing Al or the second subphase 146 containing Y after firing may be added to the paste 40 containing W or Mo, and the paste 40 may be applied and then fired. By doing so, even if diffusion from the AlN sintered body is unlikely to occur, the bonding strengthening layer 140 can contain the first subphase 144 containing Al or the second subphase 146 containing Y.

[0055] Thereafter, if necessary, a terminal hole 152 is formed in the fired electrode-embedded member 100 to expose the surface of the connection member 130. At this time, if a bond-reinforcing layer 140 is formed on the surface of the connection member 130, it is preferable to also remove the bond-reinforcing layer 140 in the area of ​​the terminal hole 152. This can increase the reliability of the electrical connection between the connection member 130 and the terminal 150. The terminal hole 152 is made smaller than the connection member 130. For example, it is preferable that the diameter of the terminal hole 152 be 90% or less of the diameter of the connection member 130.

[0056] Then, terminal 150 is connected to the exposed connection member 130 with brazing material or the like. Ni or the like can be used for the terminal 150. Furthermore, Au brazing material, Ni brazing material or the like can be used for the brazing material. One or more buffer members 154 made of W, Mo, Kovar or the like may be disposed between the connection member 130 and the terminal 150 and brazed.

[0057] In this manner, a bonding-strengthening layer 140 consisting of a main phase 142 containing W or Mo, a first subphase 144 containing Al, and a second subphase 146 containing Y can be formed at the interface between the connecting member 130 and the ceramic sintered body, and the intrusion of oxygen from between the connecting member 130 and the ceramic sintered body can be suppressed, thereby producing an electrode-embedding member 100 that can suppress deterioration of the connecting member 130. As a result, the reliability of the base 110, particularly the insulating layer 114, can be improved, and the product life of the electrode-embedding member 100 can be made longer than conventional products.

[0058] A ceramic calcined body preparation step may be provided between the compact preparation step STEP 1 and the precursor formation step STEP 4. When the ceramic calcined body preparation step is provided, the ceramic degreased body is calcined at a temperature of 1200°C to 1700°C to prepare a ceramic calcined body. This allows for higher dimensional accuracy of the outer shape of the electrode-embedded member and the embedded positions of the electrodes and connecting members. The calcination time is preferably 0.5 hours to 12 hours. The calcination atmosphere is preferably a nitrogen or inert gas atmosphere, but may also be a vacuum atmosphere. When the calcined body preparation step is provided, machining may be performed after the calcined body preparation step.

[0059] [Examples and Comparative Examples] Example 1 Ceramic raw material powder, mainly composed of AlN with 5 wt% Y2O3 added, was used for CIP molding (pressure 1 ton / cm 2 ) to obtain a green body ingot. This was machined to form a ceramic green body with a diameter of 320 mm and a thickness of 5 mm, and another ceramic green body with a diameter of 320 mm and a thickness of 40 mm. A recess with a diameter of 295 mm and a depth of 0.1 mm was provided on one side of the 40 mm thick ceramic green body, sharing the center of the green body, to accommodate an electrode. Furthermore, a recess with a diameter of 8 mm and a depth of 0.2 mm was provided at the predetermined position where the terminal would be formed to accommodate a connecting member.

[0060] Next, the ceramic compact was degreased at 550°C for 4 hours to produce a ceramic degreased body. Next, a 294mm diameter molybdenum mesh (wire diameter 0.1mm, plain weave, mesh size #50) was cut to the specified shape to prepare an electrode. Also, a connecting member measuring φ7mm x 0.2mm was produced from W pellets. Next, W powder was mixed with a binder to produce a paste containing 70wt% W powder. Next, the paste was applied to both sides and the side of the connecting member to a thickness of 100μm, and the connecting member was placed in the recess of the ceramic degreased body with a recess. An electrode was then placed on top of it and sandwiched between the other ceramic degreased body to produce an electrode-embedded member precursor.

[0061] Next, the electrode-embedding member precursor was placed in a hot press furnace, and uniaxial hot press firing was performed under the conditions of a temperature increase rate of 3°C / min, a maximum temperature of 1900°C, and a maximum temperature holding time of 2 hours while applying a force of 4 MPa in a direction perpendicular to the main surface (mounting surface) of the electrode-embedding member precursor. In this way, the electrode-embedding member was fired.

[0062] The entire surface was then ground and polished to a total thickness of 24 mm and an insulating layer thickness of 1.4 mm. Then, flat-bottom holes with a diameter of 5 mm were drilled from the rear (lower) surface of the substrate to the terminal positions, reaching the connecting members. In this way, the sample of Example 1 was produced. The samples of the Example and Comparative Examples were used to confirm whether oxidation of the connecting members would progress in subsequent tests, and therefore no terminals were connected. Two samples of Example 1 were also produced under the same conditions.

[0063] Example 2 A sample of Example 2 was produced under the same conditions as Example 1, except that the connecting member was produced from Mo pellets and the paste material was changed from W powder to Mo powder.

[0064] (Comparative Example 1) In Comparative Example 1, the connecting member was not coated with a paste containing W or Mo. A sample of Comparative Example 1 was produced under the same conditions as in Example 1 except for this.

[0065] [Performance evaluation] (Check the interface and whether or not the connecting parts are oxidized) The fabricated samples were placed in a chamber so that air could pass through the terminal holes and were maintained at 450°C for 800 hours. One sample was then cut along a cross section perpendicular to the substrate mounting surface, passing through the center of the connecting member. The cross sections of the electrodes and connecting members were exposed and polished, after which they were examined using SEM images and analyzed for composition using WDX. The SEM images were observed at 500x magnification to confirm whether a bond-reinforcing layer had formed at the interface between the connecting member and the ceramic sintered compact. WDX composition analysis confirmed whether the bond-reinforcing layer consisted of a main phase containing W or Mo, a first subphase containing Al, and a second subphase containing Y, and whether oxygen was detected at the interface between the bond-reinforcing layer and the substrate.

[0066] In the samples of Example 1 and Example 2, confirmation by SEM images confirmed that a bond-strengthening layer was formed at the interface between the connecting member and the ceramic sintered body. Furthermore, analysis of the composition by WDX confirmed that the bond-strengthening layer was a layer consisting of a main phase containing W or Mo, a first subphase containing Al, and a second subphase containing Y. On the other hand, confirmation by SEM images and WDX confirmed that in the sample of Comparative Example 1, a bond-strengthening layer consisting of a main phase containing W or Mo, a first subphase containing Al, and a second subphase containing Y was not formed at the interface between the connecting member and the ceramic sintered body.

[0067] In all samples, oxygen was detected at the interface between the bond-reinforcing layer and the substrate, and the thickness of the layer where oxygen was detected was confirmed using SEM images. As a result, the thickness of the layer where oxygen was detected in the sample of Comparative Example 1 was clearly greater than the thickness of the layer where oxygen was detected in the samples of Example 1 and Example 2. Furthermore, in the performance evaluation, some samples of the comparative example had reached their product life after 800 hours, but none of the samples of Example 1 and Example 2 had reached their product life after 800 hours. Furthermore, samples for which the interface had not been confirmed were placed in the chamber again and held at 450°C for 400 hours. No defects were observed in the samples of Example 1 and Example 2 even after a total of 1,200 hours had passed.

[0068] These results confirmed that the electrode-embedding member of the present invention can prevent oxygen from penetrating between the connecting member and the ceramic sintered body, thereby preventing deterioration of the connecting member. As a result, it is believed that the product life of the electrode-embedding member can be extended compared to conventional products. Furthermore, it was confirmed that the manufacturing method of the present invention can produce such an electrode-embedding member.

[0069] The present invention is not limited to the above-described embodiments, and 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]

[0070] 11, 12 Ceramic molding 21, 22 Ceramic degreased body 40 Paste 50 recess 60 Electrode embedding material precursor 100 Electrode embedding member 110 Base 112 Substrate mounting surface 114 Insulating layer 120 electrodes 130 Connecting member 132 Bottom surface 140 Bonding reinforcement layer 142 Main phase 144 First Vice Minister 146 Second Vice Minister 150 terminals 152 terminal hole 154 Cushioning material

Claims

1. An electrode embedding member, a base body formed in a flat plate shape from a ceramic sintered body containing AlN as a main component; an electrode embedded in the substrate; a connecting member made of W or Mo and electrically connected to the electrode and embedded in the substrate; a bonding-reinforcing layer formed on the interface between the lower surface of the connecting member and the ceramic sintered body, The electrode-embedded member, wherein the bond-reinforcing layer comprises a main phase containing W or Mo, a first subphase containing Al, and a second subphase containing Y.

2. 2. The electrode-embedded member according to claim 1, wherein, in a cross section perpendicular to the substrate mounting surface of the base, an area ratio of the first subphase and the second subphase in the region of the bonding reinforcement layer facing the base is larger than an area ratio of the first subphase and the second subphase in the region of the bonding reinforcement layer facing the connection member.

3. 3. The electrode-embedded member according to claim 1, wherein the first subphase and the second subphase are dispersed in the form of particles in the bond-reinforcing layer in a cross section perpendicular to the substrate-mounting surface of the base.

4. 3. The electrode-embedding member according to claim 1, wherein the bonding-reinforcing layer is formed on an upper surface or a side surface of the connection member.

Images