Method for manufacturing ceramic substrate for power module, and ceramic substrate for power module

Abstract

Disclosed are a method for manufacturing a ceramic substrate for a power module, and a ceramic substrate for a power module manufactured thereby. The disclosed method for manufacturing a ceramic substrate for a power module comprises the steps of: preparing a ceramic substrate in which via holes are formed; forming a plating layer in regions where via holes are formed (via hole regions) and on upper and lower surfaces of the ceramic substrate; forming a filler portion in the via hole regions, and forming a filler layer on the plating layer on the upper and lower surfaces of the ceramic substrate; and forming upper and lower electrode layers by placing metal foil on the filler layer and brazing same such that the layers are electrically connected by the filler portion. In the step of forming the filler portion and the filler layer, the surface of the plating layer on the upper and lower surfaces of the ceramic substrate is coated with a conductive filler and the via hole regions are filled with the same conductive filler such that the filler portion and the filler layer form an integrated structure.

Description

Method for manufacturing a ceramic substrate for a power module and a ceramic substrate for a power module

[0001] The present invention relates to a method for manufacturing a ceramic substrate, and more particularly to a method for manufacturing a ceramic substrate for a power module suitable for high-voltage power modules requiring high mechanical strength, thermal conductivity, and strong electrical connection performance, and to a ceramic substrate for a power module.

[0002] Power semiconductor devices are fundamental components of electronic systems that perform rectification and switching functions. Various power semiconductor devices, such as diodes, transistors, and thyristors, play a critical role in power conversion and control and are used to process high-voltage and high-current signals. Power semiconductor devices are designed to minimize power consumption by efficiently converting or amplifying electrical signals.

[0003] Power modules utilizing these power semiconductor devices are essential for applications requiring high voltage and high current, such as hybrid and electric vehicles. Power modules consist of power semiconductor devices and the substrates that mount them, and thermal dissipation characteristics, durability, and reliability are critical factors for efficient power transfer. Ceramic AMB substrates are a representative material used as the substrate for these power modules.

[0004] Ceramic AMB substrates provide stable performance even in high-voltage and high-temperature environments due to the excellent insulation and thermal conductivity of ceramics. Ceramic AMB substrates feature a structure in which electrodes are formed on the upper and lower surfaces of the ceramic substrate. The electrodes are primarily made of copper, and this structure provides high mechanical strength, thermal conductivity, and strong electrical connections, enabling the maintenance of excellent performance even in high-temperature environments.

[0005] In conventional power module semiconductor designs, a major challenge is to resolve miniaturization and heat dissipation issues while maintaining high efficiency during power conversion, due to the product characteristics of being exposed to high current and high voltage. However, reducing the size of the power module while meeting high current and high voltage requirements entails significant design difficulties, particularly in implementing electrical connections between electrodes located on the upper and lower surfaces of the ceramic AMB substrate.

[0006] The matters described in the background technology above are intended to aid in understanding the background of the invention and may include matters that are not disclosed prior art.

[0007] The technical problem that the present invention aims to solve is to provide a method for manufacturing a ceramic substrate for a power module and a ceramic substrate for a power module that can minimize power loss and resolve heat dissipation problems by forming the shortest electrical and thermal path between the upper and lower metal layers (electrode layers) of the ceramic substrate.

[0008] Another technical problem that the present invention aims to solve is to provide a method for manufacturing a ceramic substrate for a power module and a ceramic substrate for a power module that can exhibit structurally high mechanical strength, thermal conductivity, and strong electrical connection performance by improving the bonding strength of the metal layer (electrode layer).

[0009] According to a preferred embodiment of the present invention as a means of solving the problem, a method for manufacturing a ceramic substrate for a power module comprises the steps of: preparing a ceramic substrate having via holes formed therein; forming a plating layer on the upper and lower surfaces of the ceramic substrate and the via hole region; forming a filler portion in the via hole region and forming a filler layer on the plating layer on the upper and lower surfaces of the ceramic substrate; and placing a metal foil on the filler layer and then brazing it to form upper and lower electrode layers so as to be electrically connected by the filler portion. In the step of forming the filler portion and the filler layer, the surface of the plating layer on the upper and lower surfaces of the ceramic substrate is coated with a conductive filler, and the via hole region is filled with the conductive filler so that the filler portion and the filler layer form an integrated structure.

[0010] Here, in the step of forming the filler part and the filler layer, the filler part and the filler layer can be formed into an integrated structure through paste printing.

[0011] According to another preferred embodiment of the present invention as a means of solving the problem, a method for manufacturing a ceramic substrate for a power module is provided, comprising the steps of: preparing a ceramic substrate having via holes formed therein; forming a plating layer on the via hole region and on the upper and lower surfaces of the ceramic substrate; forming a filler portion by inserting a copper block (Cu Block) into the via holes; forming a filler layer by simultaneously coating the plating layer exposed to the outside and the upper and lower surfaces of the filler portion with a conductive filler; and forming upper and lower electrode layers so as to be electrically connected by the filler portion by placing a metal foil on the filler layer and then brazing bonding them.

[0012] Here, in the step of forming the filler layer, the filler layer can be formed by coating a conductive filler on a plating layer around the filler portion through paste printing.

[0013] In a method for manufacturing a ceramic substrate for a power module according to a preferred embodiment and another embodiment of the present invention, in the step of preparing the ceramic substrate, one or more via holes are formed in the ceramic substrate through mechanical processing or laser processing, and then a ceramic substrate from which residues and contaminants are removed is prepared by a cleaning treatment.

[0014] In a method for manufacturing a ceramic substrate for a power module according to a preferred embodiment and another embodiment of the present invention, in the step of forming the plating layer, a conductive metal made of one of Cu, Ag, or Ag-Pb alloy can be vacuum deposited on the via hole region and the upper and lower surfaces of the ceramic substrate to form the plating layer.

[0015] In a method for manufacturing a ceramic substrate for a power module according to a preferred embodiment and another embodiment of the present invention, the conductive filler may include an active metal made of one of the materials Cu, Ag, and Ag-Cu alloy.

[0016] A method for manufacturing a ceramic substrate for a power module according to a preferred embodiment and other embodiments of the present invention may further include the step of machining or etching the upper and lower electrode layers.

[0017] According to another preferred embodiment of the present invention as a means of solving the problem, a ceramic substrate for a power module manufactured by the above-described manufacturing method comprises: a ceramic substrate; one or more via holes formed to penetrate the ceramic substrate in the thickness direction; a plating layer formed on the upper and lower surfaces of the ceramic substrate and via hole regions; a filler portion formed in the via holes to contact the plating layer formed in the via hole regions; a filler portion formed on the plating layer on the upper and lower surfaces of the ceramic substrate; and an upper metal layer and a lower metal layer bonded to the plating layer on the upper and lower surfaces of the ceramic substrate via the filler portion, wherein the upper metal layer and the lower metal layer are electrically connected by the filler portion.

[0018] In a ceramic substrate for a power module according to another preferred embodiment of the present invention, the plating layer may be a conductive metal made of one of Cu, Ag, or Ag-Pb alloy.

[0019] In a ceramic substrate for a power module according to another preferred embodiment of the present invention, the filler portion and the filler layer may be formed integrally.

[0020] In a ceramic substrate for a power module according to another preferred embodiment of the present invention, the filler portion and the filler layer may include an active metal made of one of the materials Cu, Ag, and Ag-Cu alloy.

[0021] In a ceramic substrate for a power module according to another preferred embodiment of the present invention, the filler portion may be formed by inserting a copper block (Cu Block) into the via hole so as to protrude to the upper and lower parts of the ceramic substrate.

[0022] Here, the filler layer may be formed on the plating layer around the filler portion protruding from the upper and lower parts of the ceramic substrate.

[0023] According to the present invention, an electrical and thermal path of the shortest distance between the upper and lower metal layers (electrode layers) of a ceramic substrate can be formed through the filler portion. As a result, current flow is smooth, power loss is minimized, and a high level of heat dissipation performance can be achieved. Consequently, stable and highly reliable power transmission is possible even in high-voltage and high-current environments, thereby enabling miniaturization and weight reduction along with improved efficiency of the power module.

[0024] Furthermore, in one embodiment of the present invention, a manufacturing method that structurally integrates the filler part and the filler layer is adopted, thereby eliminating the need for a separate process for forming the filler part. This shortens the manufacturing process and increases the production speed of the product, which can significantly improve mass production capabilities. Additionally, by omitting or reducing unnecessary processes through process shortening, there is an effect of reducing overall production costs.

[0025] In addition, the present invention has the advantage of providing a manufacturing method capable of realizing a strong physical bond between the filler portion and the filler layer, and through the strong physical bond between the filler portion and the filler layer, the bonding strength of the metal layer (electrode layer) is improved, and a ceramic substrate for a power module can be realized that exhibits structurally high mechanical strength, thermal conductivity, and strong electrical connection performance.

[0026] As a result, a ceramic substrate for a power module can be provided that enables the implementation of a power module suitable for a high-efficiency power conversion system requiring performance stabilization in a high-temperature environment.

[0027] FIG. 1 is a flowchart illustrating a method for manufacturing a ceramic substrate for a power module according to one embodiment of the present invention.

[0028] FIG. 2 is a schematic diagram illustrating a substrate manufacturing process according to a method for manufacturing a ceramic substrate for a power module according to one embodiment of the present invention.

[0029] FIG. 3 is a flowchart illustrating a method for manufacturing a ceramic substrate for a power module according to another embodiment of the present invention.

[0030] FIG. 4 is a schematic diagram illustrating a substrate manufacturing process according to a method for manufacturing a ceramic substrate for a power module according to another embodiment of the present invention.

[0031] FIG. 5 is a schematic cross-sectional view showing a preferred embodiment of a ceramic substrate for a power module manufactured by the method for manufacturing a ceramic substrate for a power module according to the present invention.

[0032] FIG. 6 is a schematic cross-sectional view showing another preferred embodiment of a ceramic substrate for a power module manufactured by the method for manufacturing a ceramic substrate for a power module according to the present invention.

[0033] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0034] In describing the embodiments of the present invention, identical or similar components are assigned the same reference numerals, and redundant descriptions thereof are omitted. Furthermore, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the embodiments disclosed in this specification.

[0035] In addition, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings, and it should be noted that they include all modifications, equivalents, and substitutions that fall within the concept and technical scope of the present invention.

[0036] Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0037] Furthermore, when it is mentioned that a component is "connected" or "joined" to another component, it should be understood that while it may be directly connected or joined to that other component, there may also be other components in between.

[0038] On the other hand, when it is stated that one component is "directly connected" or "directly coupled" to another component, it should be understood that there are no other components in between.

[0039] Furthermore, terms such as "comprising," "having," and "having" used in describing embodiments of the present invention are intended to specify the existence of features, numbers, steps, actions, components, parts, or combinations thereof of the invention, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0040] And the fact that one component is in the "front," "rear," "upper," or "lower" of another component includes, unless there are special circumstances, not only being placed in the "front," "rear," "upper," or "lower" of the other component in direct contact with it, but also having another component placed in between.

[0041] The drawings are intended solely to facilitate an understanding of the concept of the present invention and should not be interpreted as limiting the scope of the invention. Furthermore, it is noted that relative thicknesses, lengths, or sizes in the drawings may be exaggerated for convenience and clarity of explanation.

[0042] FIG. 1 is a flowchart for explaining a method for manufacturing a ceramic substrate for a power module according to one embodiment of the present invention, and FIG. 2 is a schematic diagram of a process schematically illustrating a substrate manufacturing process according to a method for manufacturing a ceramic substrate for a power module according to one embodiment of the present invention.

[0043] Referring to FIGS. 1 and 2, a manufacturing method according to one embodiment includes the step of preparing a ceramic substrate (S100) and the step of forming a plating layer (S200). In the step of preparing a ceramic substrate (S100), a ceramic substrate (10) having via holes (12) formed therein is prepared, and in the step of forming a plating layer (S200), a process of forming a plating layer (14) on both sides (upper and lower surfaces in the drawing) of the ceramic substrate (10) and the area where via holes (12) are formed (hereinafter referred to as the 'via hole area') may be performed.

[0044] In the step (S100) of preparing a ceramic substrate, a plurality of via holes (12) are formed in the ceramic substrate (10) through mechanical processing or laser processing, and then a cleaning treatment is performed to prepare a ceramic substrate (10) from which residues and contaminants have been removed. The ceramic substrate (10) may be one of alumina (Al2O3), zirconia-reinforced alumina (ZTA), aluminum nitride (AlN), and silicon nitride (Si3N4), and the diameter of the via holes (12) is preferably 0.15 mm to 0.3 mm.

[0045] In the step of forming the plating layer (S200), one conductive metal among Cu, Ag, or Ag-Pb alloy can be selected to form the plating layer (14) on the via hole region and the upper and lower surfaces of the ceramic substrate (10) by vacuum deposition. In the step of forming the plating layer (S200), preferably, the plating layer (14) can be formed using vacuum deposition sputtering, which enables uniform thin film formation and precise thickness control.

[0046] In one embodiment, the via holes (12) may be formed in multiple numbers, and the area occupied by the multiple via holes (12) is preferably 10% or more of the total area of ​​the ceramic substrate. This is because, due to the characteristics of a power module that processes high voltage and high current signals, the area of ​​the via holes (12) must be 10% or more of the ceramic substrate area to facilitate the dispersion and conduction of high current, thereby preventing problems such as short circuits and overheating and increasing the efficiency of high-speed current movement.

[0047] A method for manufacturing a ceramic substrate for a power module according to one embodiment also includes a step (S300) of forming a filler portion (16) by filling a via hole area where a plating layer (14) is formed through the plating step (S200) described above and forming a filler layer (17) on the surface of the plating layer (14) exposed above and below the ceramic substrate (10), and a step (S400) of forming upper and lower electrode layers (18a, 18b) by placing a metal foil on the filler layer (17) and then brazing, wherein the upper and lower electrode layers (18a, 18b) are connected so as to be electrically integrated by the filler portion (16).

[0048] In the step (S200) of forming the filler portion (16) and the filler layer (17), the surface of the plating layer (14) on the upper and lower surfaces of the ceramic substrate (10) is coated with a conductive filler, and the via hole area is filled with the conductive filler so that the filler portion (16) and the filler layer (17) form an integrated structure. As a preferred example, the filler portion (16) formed in the via hole (12) and the filler layer (17) on the plating layer (14) on the upper and lower surfaces of the ceramic substrate (10) can be formed integrally using paste printing.

[0049] More specifically, a conductive paste composed of an active metal powder made of one of Cu, Ag, or Ag-Cu alloy and a binder material is printed to a predetermined thickness on the surface of a ceramic substrate (10), and then pressure or vibration is applied so that a portion of the paste is filled into the via hole (12). Afterward, by drying at a predetermined temperature, the filler portion (16) and the filler layer (17) can be made into an integrated structure.

[0050] Another method for forming the filler portion (16) and the filler layer (17) as an integrated structure may be to use electroplating, which utilizes an electrochemical reaction to deposit a thin metal layer on the metal surface. This makes it possible to form the filler portion (16) and the filler layer (17) as an integrated structure through electroplating, because a conductive metal is coated to a predetermined thickness on the surface of the ceramic substrate (10) and the via hole (12) during the plating layer (14) formation step.

[0051] In the step of forming the upper and lower electrode layers (18a, 18b), a metal foil is placed on the filler layer (17) and brazed to form the upper and lower electrode layers (18a, 18b). During the sintering process for brazing, the plating layer (14), the filler portion (16), and the filler layer (17) melt, and the active metal component reacts with the ceramic substrate (10) to form a chemical bond, and forms a mechanically strong bond with the metal foil through thermal fusion.

[0052] The metal foil may be a thin conductive metal having an area (or size) corresponding to the planar area (or size) of the ceramic substrate (10). For example, the metal foil may be a conductive metal such as copper (Cu) or aluminum (Al) that is rolled or chemically processed into a very thin film.

[0053] Here, as previously mentioned, when a paste composed of active metal powder and a binder is used as a conductive filler, the metal particles contained in the filler portion (16) and the filler layer (17) are firmly bonded during the firing process, and the binder is removed so that the filler portion (16) and the filler layer (17) can be solidified. As a result, the mechanical strength of the substrate is improved, and the upper and lower electrode layers (18a, 18b) can form a solid and stable electrical connection through the solidified filler portion (16).

[0054] When the upper electrode layer (18a, 18b) and the lower electrode layer (18a, 18b) are joined (brazed) to the upper and lower surfaces of the ceramic substrate (10) through a brazing process, the manufacturing of the ceramic substrate according to the present embodiment can be completed by finally processing the upper electrode layer (18a, 18b) and the lower electrode layer (18a, 18b) into a shape planned in the design to form a pattern electrode (not shown). Here, the pattern electrode can be formed using a known mechanical processing or etching process.

[0055] Since the ceramic substrate (10) is an electrically insulating material, it is difficult to make an electrical connection between the electrode layers (18a, 18b) bonded to the upper and lower surfaces. In particular, in the case of a power module, loop connection and electrical circuit connection through a semiconductor chip are required, but if the electrical loop becomes long, the inductance value increases, which is disadvantageous for the movement of high-speed current. In the embodiment, the length of the electrical loop can be minimized by forming a filler part (16) that electrically connects the upper and lower electrode layers (18a, 18b) using a via hole (12).

[0056] In other words, the filler section can form the shortest electrical and thermal pathways between the upper and lower metal layers (electrode layers) of the ceramic substrate. This facilitates smooth current flow, minimizes power loss, and enables high-level heat dissipation performance. Consequently, stable and reliable power transmission is possible even in high-voltage and high-current environments, allowing for improved efficiency of the power module as well as miniaturization and weight reduction.

[0057] Furthermore, by adopting a manufacturing method that structurally integrates the filler section and the filler layer, a separate process for forming the filler section can be omitted. This shortens the manufacturing process and increases product production speed, thereby significantly improving mass producibility. Additionally, by omitting or reducing unnecessary steps through process shortening, overall production costs can also be reduced.

[0058] In addition, according to the method for manufacturing a ceramic substrate according to one embodiment, a strong physical bond can be realized between the filler portion and the filler layer, and due to the strong physical bond between the filler portion and the filler layer, the bonding strength with the metal layer (electrode layer) is improved, and a ceramic substrate for a power module that exhibits structurally high mechanical strength, thermal conductivity, and strong electrical connection performance can be realized.

[0059] FIG. 3 is a flowchart for explaining a method for manufacturing a ceramic substrate for a power module according to another embodiment of the present invention, and FIG. 4 is a schematic process diagram schematically illustrating a substrate manufacturing process according to a method for manufacturing a ceramic substrate for a power module according to another embodiment of the present invention.

[0060] The method for manufacturing a ceramic substrate for a power module according to another embodiment differs from the embodiment in that a metal block (e.g., a Cu block) made of a conductive material is directly inserted into a via hole area of ​​a ceramic substrate (10) having a plating layer (14) formed thereon to form a filler portion (16'), in that a via hole area is filled with a conductive material through electroplating or paste printing and a filler portion (16) is formed by sintering.

[0061] In a method for manufacturing a ceramic substrate for a power module according to another embodiment, the same procedure as the previously described embodiment is followed up to the step (S100' and S200') of preparing a ceramic substrate (10) having a plurality of via holes (12) and forming a plating layer (14) on the ceramic substrate (10) through a plating process (e.g., vacuum sputtering deposition). Therefore, redundant descriptions of identical parts are omitted below, and only parts that differ from the manufacturing method of the first embodiment will be mentioned and described.

[0062] Referring to FIGS. 3 and 4, a method for manufacturing a ceramic substrate for a power module according to another embodiment involves forming a filler portion (16') by directly inserting a conductive block into a via hole (12) in which a plating layer is formed through a series of pretreatment processes, such as preparing a ceramic substrate (10) and a plating process (S300'). Subsequently, the externally exposed plating layer (14) (the plating layer on the upper and lower surfaces of the ceramic substrate) and the externally exposed filler portion (16') are simultaneously coated with a conductive filler to form a filler layer (17') (S400').

[0063] In a method for manufacturing a ceramic substrate for a power module according to another embodiment, the conductive block inserted into the via hole (12) in the step of forming the filler portion (S300') may be a copper block (Cu Block). Additionally, in the step of forming a filler layer (S400') by simultaneously coating the upper and lower surfaces of the externally exposed plating layer (14) and the filler portion (16') with a conductive filler, the filler layer (17') may be formed through a paste printing process in which a conductive paste containing conductive metal particles is coated.

[0064] In forming a filler layer (17') through a paste printing process, a conductive paste composed of an active metal powder made of one of Cu, Ag, or Ag-Cu alloy and a binder material is printed on the surface of a ceramic substrate (10) to a predetermined thickness, and then the filler layer (17') is formed by drying under a predetermined temperature condition. In some cases, the filler layer (17') can also be formed through an electroplating process.

[0065] When the filler layer (17') is formed, the next step (S500') may be performed to form upper and lower electrode layers (18a, 18b) by placing a metal foil on the filler layer (17') and brazing it. In the step (S500') of forming the upper and lower electrode layers, the upper and lower electrode layers (18a, 18b) may be formed by placing a metal foil on the filler layer (17') and brazing it, similar to the manufacturing method according to the above-described embodiment. Here, the metal foil may be made of copper (Cu) or aluminum (Al).

[0066] During the sintering process for brazing, as the filler layer (17') melts, the active metal component contained in the filler layer (17') reacts with the ceramic substrate (10) to form a chemical bond, and forms a mechanically strong bond with the metal foil through thermal fusion. In this case, if a conductive paste is used as the conductive filler, the binder component is removed during the sintering process, and the overall mechanical strength of the substrate can be improved by the solidified filler layer (17').

[0067] When the upper electrode layer (18a) and the lower electrode layer (18b) are joined (brazed) to the upper and lower surfaces of the ceramic substrate (10) through a brazing process, the manufacturing of the ceramic substrate according to the present embodiment can be completed by finally processing the upper electrode layer (18a) and the lower electrode layer (18b) into a shape planned in the design to form a pattern electrode. Here, the pattern electrode can also be formed using a known mechanical processing or etching process.

[0068] According to a method for manufacturing a ceramic substrate for a power module according to another embodiment as described above, a high-density conductive block (e.g., a Cu block) in which no bubbles or voids occur is directly inserted into a via hole in which a plating layer is formed through a series of pretreatment processes such as ceramic substrate preparation and plating process, thereby forming an electrical and thermal connection passage (filler part) between the upper and lower electrode layers. Accordingly, the electrical and thermal stability and mechanical strength of the substrate can be significantly improved.

[0069] FIGS. 5 and 6 are schematic cross-sectional views of a ceramic substrate for a power module manufactured by a manufacturing method according to an embodiment of the present invention described above.

[0070] Referring to FIGS. 5 and 6, a ceramic substrate (1) for a power module according to an embodiment includes a ceramic substrate (10) and a plurality of via holes (12) formed to penetrate the ceramic substrate (10) in the thickness direction. Additionally, it includes a plating layer (14) formed on the upper and lower surfaces of the via hole region (a region where the via holes (12) are formed) and the ceramic substrate (10), and a filler portion (16) formed in the via holes (12) to contact the plating layer (14) formed in the via hole region.

[0071] The ceramic substrate (10) may be one of alumina (Al2O3), zirconia-reinforced alumina (ZTA), aluminum nitride (AlN), or silicon nitride (Si3N4). Additionally, the diameter of the via hole (12) formed in the thickness direction of the ceramic substrate (10) is preferably 0.15 mm to 0.3 mm. The plating layer (14) may be formed by vacuum depositing a conductive metal, one of Cu, Ag, or Ag-Pb alloy, onto the via hole area and the upper and lower surfaces of the ceramic substrate (10).

[0072] A filler layer (17) may be formed on the plating layer (14) on the upper and lower surfaces of the ceramic substrate (10). The filler layer (17) may be formed integrally with the filler portion (16) formed in the via hole (12), as in a preferred embodiment shown in FIG. 5. For example, the filler portion (16) and the filler layer (17) may be formed integrally through a series of processes in which a conductive paste composed of an active metal powder made of one of Cu, Ag, or an Ag-Cu alloy and a binder material is printed to a predetermined thickness on the surface of the plating layer (14), pressure or vibration is applied so that a portion of the paste is filled into the via hole (12), and then dried at a predetermined temperature.

[0073] As another preferred example, as illustrated in FIG. 6, the filler portion (16') may be formed by a copper block (Cu Block) inserted (or pressed) into the via hole (12). In this case, the filler portion (16') formed by the copper block is formed with a length such that its upper and lower surfaces can be aligned on the same plane as the upper and lower surfaces of the plating layer (14) of the ceramic substrate (10), and a filler layer (17') may be formed through a process of simultaneously coating the upper and lower surfaces of the externally exposed plating layer (14) and the filler portion (16') with a conductive filler.

[0074] A ceramic substrate for a power module according to an embodiment also includes an upper metal layer and a lower metal layer that are firmly bonded to the plating layers on the upper and lower surfaces of the ceramic substrate via a filler layer. At this time, the upper metal layer and the lower metal layer form a thermally and electrically stable yet robust connection through the filler portion formed in the via hole, thereby significantly improving the electrical and thermal stability and mechanical strength of the substrate.

[0075] The above description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention.

[0076] Accordingly, the embodiments disclosed in this invention are intended to illustrate, not limit, the technical concept of the invention, and the scope of the technical concept of the invention is not limited by these embodiments. The scope of protection of this invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of this invention.

Claims

1. A method for manufacturing a ceramic substrate for a power module, wherein A step of preparing a ceramic substrate having via holes formed therein; A step of forming a plating layer on the via hole region and on the upper and lower surfaces of the ceramic substrate; A step of forming a filler portion in the via hole region and forming a filler layer on the plating layer on the upper and lower surfaces of the ceramic substrate; and The method includes the step of forming upper and lower electrode layers by placing a metal foil on the filler layer and then brazing it to be electrically connected by the filler portion; In the step of forming the filler portion and the filler layer, A method for manufacturing a ceramic substrate for a power module, wherein the surface of the plating layer on the upper and lower surfaces of the ceramic substrate is coated with a conductive filler, and the via hole area is filled with the conductive filler to form an integrated structure in which the filler part and the filler layer are formed.

2. A method for manufacturing a ceramic substrate for a power module, A step of preparing a ceramic substrate having via holes formed therein; A step of forming a plating layer on the via hole region and on the upper and lower surfaces of the ceramic substrate; A step of forming a filler portion by inserting a copper block (Cu Block) into the above via hole; A step of forming a filler layer by simultaneously coating the externally exposed plating layer and the upper and lower surfaces of the filler portion with a conductive filler; and A method for manufacturing a ceramic substrate for a power module, comprising the step of forming upper and lower electrode layers so as to be electrically connected by the filler layer by placing a metal foil on the filler layer and then brazing.

3. In Paragraph 1 or 2, In the step of forming the plating layer above, A method for manufacturing a ceramic substrate for a power module, wherein a conductive metal made of one of Cu, Ag, or Ag-Pb alloy is vacuum deposited on the via hole region and the upper and lower surfaces of the ceramic substrate to form the plating layer.

4. In Paragraph 1, In the step of forming the above filler part and filler layer, A method for manufacturing a ceramic substrate for a power module, wherein the filler portion and the filler layer are formed into an integrated structure through paste printing.

5. In Paragraph 2, In the step of forming the above filler layer, A method for manufacturing a ceramic substrate for a power module, wherein a conductive filler is coated on a plating layer surrounding the filler portion through paste printing to form the filler layer.

6. In Paragraph 1 or 2, The above conductive filler is, A method for manufacturing a ceramic substrate for a power module comprising an active metal made of one of Cu, Ag, or Ag-Cu alloy.

7. A ceramic substrate for a power module manufactured by the manufacturing method of claim 1 or 2, wherein Ceramic substrate; One or more via holes formed to penetrate the ceramic substrate in the thickness direction; A plating layer formed on the via hole region and on the upper and lower surfaces of the ceramic substrate; A filler portion formed in the via hole to contact the plating layer formed in the via hole region; A filler layer formed on the plating layer on the upper and lower surfaces of the ceramic substrate; and It includes an upper metal layer and a lower metal layer bonded to the plating layers on the upper and lower surfaces of the ceramic substrate via the above filler layer; A ceramic substrate for a power module, wherein the upper metal layer and the lower metal layer are electrically connected by the filler portion.

8. In Paragraph 7, A ceramic substrate for a power module, wherein the above-mentioned filler portion and filler layer are formed as an integrated structure.

9. In Paragraph 7, The above filler part is, A ceramic substrate for a power module formed by inserting a copper block (Cu Block) into the via hole of the ceramic substrate.

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