Ceramic substrate unit for power module and method for manufacturing ceramic substrate unit for power module

Abstract

Disclosed are a ceramic substrate unit for a power module and a method for manufacturing the ceramic substrate unit for a power module. The disclosed ceramic substrate unit for a power module comprises: a ceramic substrate having metal layers provided on the upper surface and the lower surface of a ceramic base material; a heat sink bonded to the lower metal layer of the ceramic substrate and having a plating layer formed on the upper surface; and a bonding layer disposed between the lower metal layer and the heat sink. The bonding layer contains metal particles that are chemically and mechanically compatible with the plating layer, and the plating layer and the bonding layer provide thermal and mechanical bonding functions between the ceramic substrate and the heat sink.

Description

Ceramic substrate unit for power module and method for manufacturing a ceramic substrate unit for power module

[0001] The present invention relates to a ceramic substrate unit, and more particularly to a ceramic substrate unit for a power module suitable for a high-voltage power module requiring high mechanical strength, thermal conductivity, and heat dissipation performance, and a method for manufacturing the ceramic substrate unit.

[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 achieve miniaturization while maintaining high efficiency during power conversion, and to resolve heat dissipation issues, particularly given the product's exposure to high current and voltage. This is because high temperatures generated by high-current and high-voltage operation can lead to semiconductor chip degradation, which in turn can significantly degrade the power module's performance.

[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 ceramic substrate unit for a power module and a method for manufacturing the ceramic substrate unit for a power module, wherein a heat sink is bonded to the lower metal layer of the ceramic substrate, thereby having excellent electrical and thermal conductivity and effectively dissipating heat generated from a semiconductor chip.

[0008] Another technical problem that the present invention aims to solve is to provide a ceramic substrate unit for a power module and a method for manufacturing the ceramic substrate unit for a power module, which can achieve a stable and robust bond between a lower metal layer of ceramic substrates of different materials and a heatsink.

[0009] According to one aspect of the present invention as a means of solving the problem, a ceramic substrate for a power module comprises a ceramic substrate including a ceramic substrate and a metal layer disposed on the upper and lower surfaces of the ceramic substrate, a heat sink bonded to the lower metal layer of the ceramic substrate and having a plating layer formed on its upper surface, and a bonding layer disposed between the lower metal layer and the heat sink, wherein the bonding layer comprises metal particles chemically and mechanically compatible with the plating layer, and the metal particles exist in the form of nanoparticles, fine powder, or a sinterable form, and the plating layer and the bonding layer provide a thermal and mechanical bonding function between the ceramic substrate and the heat sink.

[0010] In a ceramic substrate unit for a power module according to one aspect of the present invention, the heat sink may be composed of a metal or a metal alloy having a lower melting point and higher corrosion resistance than the lower metal layer.

[0011] In a ceramic substrate unit for a power module according to one aspect of the present invention, the lower metal layer may preferably be formed from one of the following materials: Cu, Cu alloy, ETP (Electrolytic Tough Pitch), and OFC (Oxygen-Free Copper).

[0012] In a ceramic substrate unit for a power module according to one aspect of the present invention, the heatsink may be made of Al or an Al alloy.

[0013] In a ceramic substrate unit for a power module according to one aspect of the present invention, the bonding layer may include metal particles having the same main component as the plating layer.

[0014] In a ceramic substrate unit for a power module according to one aspect of the present invention, the plating layer is an Ag plating layer, and the bonding layer may include Ag particles identical to those of the plating layer.

[0015] According to another aspect of the present invention as a means of solving the problem, a method for manufacturing a ceramic substrate unit for a power module comprises the steps of: preparing a ceramic substrate having metal layers on the upper and lower surfaces of the ceramic substrate; and bonding a heat sink to the lower metal layer of the ceramic substrate. In the step of bonding the heat sink, a plating layer is formed on the upper surface of the heat sink, a bonding layer is placed between the lower metal layer and the heat sink, and the heat sink is bonded to the lower metal layer through one of sintering, brazing, or diffusion bonding. The bonding layer comprises metal particles that are chemically and mechanically compatible with the plating layer.

[0016] In a method for manufacturing a ceramic substrate unit for a power module according to another aspect of the present invention, the lower metal layer may be formed from one of the following materials: Cu, Cu alloy, ETP (Electrolytic Tough Pitch), and OFC (Oxygen-Free Copper).

[0017] In a method for manufacturing a ceramic substrate unit for a power module according to another aspect of the present invention, the heatsink may be composed of Al or an Al alloy.

[0018] In a method for manufacturing a ceramic substrate unit for a power module according to another aspect of the present invention, the plating layer is an Ag plating layer, and the bonding layer may be an Ag-based film-shaped sintered body containing Ag particles.

[0019] According to an embodiment of the present invention, by attaching a heat sink to a ceramic substrate, the heat dissipation characteristics required for a power module that processes high voltage and high current signals can be satisfied. In particular, since it is bonded to the ceramic substrate through Ag Sintering, it possesses robust bonding strength and excellent thermal conductivity even in high-temperature environments. As a result, a high-power module capable of stable and highly reliable power transmission even in high voltage and high current environments can be realized.

[0020] In addition, by adopting a configuration in which an air-cooled or water-cooled heatsink, composed of one of the Micro Channel, Pin Fin, Micro Jet, or Slit types, is directly bonded to one side of a ceramic substrate, multiple layers of cooling materials can be eliminated. Through this, cost reduction and improved mass production capabilities resulting from process reduction can be expected.

[0021] FIG. 1 is a partially exploded perspective view illustrating a ceramic substrate unit for a power module according to an embodiment of the present invention.

[0022] FIG. 2 is a cross-sectional view of a ceramic substrate unit for a power module according to an embodiment of the present invention.

[0023] FIG. 3 is a flowchart illustrating a method for manufacturing a ceramic substrate unit for a power module according to an embodiment of the present invention.

[0024] FIG. 4 is a schematic diagram illustrating a process for manufacturing a ceramic substrate for a power module according to an embodiment of the present invention.

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] FIG. 1 is a partially exploded perspective view illustrating a ceramic substrate unit for a power module according to an embodiment of the present invention, and FIG. 2 is a combined cross-sectional view of a ceramic substrate unit for a power module according to an embodiment of the present invention.

[0035] Referring to FIGS. 1 and 2, a ceramic substrate unit (1) according to an embodiment of the present invention includes a ceramic substrate (10) and a heat sink (20). The ceramic substrate (10) may be one of an AMB (Active Metal Brazing) substrate, a DBC (Direct Bonded Copper) substrate, or a TPC (Thick Printing Copper) substrate. These ceramic substrates (10) are substrates in which a metal is directly bonded to a ceramic substrate (12).

[0036] The ceramic substrate (10) may be configured to include a ceramic substrate (12) and an upper metal layer (14) and a lower metal layer (16) formed on the upper and lower surfaces, respectively, of the ceramic substrate (12) so as to have high mechanical strength and thermal conductivity and to effectively dissipate heat generated from a semiconductor chip (not shown). Here, the thickness of the ceramic substrate (12) may be 0.32t, and the thickness of the upper metal layer (14) and the lower metal layer (16) may be 0.3t.

[0037] The ceramic substrate (12) may be made of an oxide-based or nitride-based ceramic material. For example, the ceramic substrate (12) may be composed of one of alumina (Al2O3), zirconia-reinforced alumina (ZTA), aluminum nitride (AlN), or silicon nitride (Si3N4). The upper metal layer (14) and the lower metal layer (16) may be formed by brazing a thin metal foil to the upper and lower surfaces of the ceramic substrate (12).

[0038] The upper metal layer (14) can be formed in the shape of a predetermined circuit pattern. For example, the upper metal layer (14) can be formed by brazing a thin metal foil in the shape of a flat plate onto the upper surface of a ceramic substrate (12), and then processing it into an electrode pattern suitable for mounting a semiconductor chip or driving element through an etching process. This upper metal layer (14) can be made of one of Cu, Cu alloy, ETP (Electrolytic Tough Pitch), or OFC (Oxygen-Free Copper).

[0039] A lower metal layer (16) can be formed on the lower surface of a ceramic substrate (12). The lower metal layer (16) can be provided in a flat plate shape to facilitate heat transfer. The lower metal layer (16) can be formed by a process of brazing a thin metal foil in the shape of a flat plate onto the lower surface of the ceramic substrate (12). This lower metal layer (16) can be made of the same metal or metal alloy as the upper metal layer (14). For example, it can be made of one of Cu, Cu alloy, ETP, or OFC.

[0040] A heat sink (20) can be bonded to a lower metal layer (16) of a ceramic substrate (10). The heat sink (20) may be made of a metal or metal alloy having a lower melting point than the lower metal layer (16), high corrosion resistance, and excellent thermal conductivity. For example, the heat sink (20) may be made of Al or an Al alloy. Alternatively, it may be made of an aluminum-based composite material. An aluminum-based composite material may be, for example, AlSiC.

[0041] The heat sink (20) can be formed with a thickness of 4 to 5 times the thickness of the ceramic substrate (10). When the thickness of the ceramic substrate (10) is set to the previously exemplified values ​​(thickness of the ceramic substrate 0.32t, thickness of the upper metal layer and lower metal layer each 0.3t), it is preferable to set the thickness of the heat sink (20) to 3.8t. This is a value that takes into account the optimal thickness designed to efficiently and quickly dissipate heat while suppressing thermal deformation (e.g., warping) of the ceramic substrate (10) exposed to high heat.

[0042] The heat sink (20) can be operated by either air cooling or water cooling. Air cooling uses air as a refrigerant, while water cooling can be achieved by forcibly circulating a refrigerant such as cooling water, liquid nitrogen, alcohol, or other solvents. For example, a water-cooled heat sink (20) can effectively prevent overheating of the semiconductor chip by controlling the amount of heat dissipation by appropriately adjusting the flow rate of the refrigerant and performing forced cooling through the continuously circulating refrigerant.

[0043] The heat sink (20) may be configured as any one of the Micro Channel, Pin Fin, Micro Jet, or Slit types. Hereinafter, as a preferred example in the embodiment, a plurality of rod-shaped protrusions (24) are arranged on the lower surface of a flat plate-shaped flat portion (22), and a slit-type heat sink (20) in which the plurality of rod-shaped protrusions (24) are arranged horizontally on the lower surface of the flat portion (22) with spacing between them will be examined as an example.

[0044] The heat sink (20) may have a flat portion (22) whose upper surface is bonded to the lower metal layer (16) of the ceramic substrate (10), and a plurality of rod-shaped protrusions (24) disposed on the lower surface of the flat portion (22). The upper surface of the flat portion (22) is in contact with the lower metal layer (16), and the plurality of rod-shaped protrusions (24) may be disposed on the lower surface of the flat portion (22) at intervals from each other so as to form a passage (p) through which a refrigerant flows between adjacent protrusions (24).

[0045] The flat portion (22) may be provided in a flat plate shape to maximize the bonding area with the lower metal layer (16) and to increase bonding strength and heat dissipation performance. Additionally, the plurality of protrusions (24) may be provided in various pin shapes, such as a column with a square cross-section shape as illustrated in the drawing, as well as a cylinder, a polygonal column, a teardrop shape, a diamond shape, etc. These protrusions (24) may be realized in the aforementioned shapes by mold processing, etching processing, milling processing, or other processing.

[0046] In designing the heat sink (20), the thickness of the flat portion (22) can be formed to be thicker than the thickness of the plurality of protrusions (24). For example, if the thickness of the flat portion (22) is 2.0 mm, the thickness of the protrusions (24) can be set to 1.0 mm. Since the flat portion (22) is a part that receives heat by contacting the lower metal layer (16) of the ceramic substrate (10), a design that is thicker than the thickness of the protrusions (24) is advantageous for increasing heat dissipation efficiency by widely spreading heat and suppressing warping in a high-temperature environment.

[0047] The heat sink (20) can be firmly bonded to the lower metal layer (16) of the ceramic substrate (10) via a plating layer (21) and a bonding layer (30). The plating layer (21) can be formed on the upper surface of the heat sink (20) with a predetermined thickness using one of vacuum deposition, electroplating, or electroless plating methods. In the embodiment, the thickness of the plating layer (16) formed on the upper surface of the heat sink (20) may be thinner than the bonding layer (30).

[0048] The bonding layer (30) is disposed between the lower metal layer (16) and the heat sink (20), more specifically, between the lower metal layer (16) and the plating layer (21) of the heat sink (20), and thermally and mechanically bonds the ceramic substrate (10) and the heat sink (20) by fusing with the plating layer (21). The bonding layer (30) may include metal particles that are chemically and mechanically compatible with the plating layer (21).

[0049] The bonding layer (30) may preferably include metal particles that have the same main component as the plating layer (21). Here, the metal particles may exist in the form of nanoparticles, fine powder, or a sinterable form.

[0050] In the embodiment, the plating layer (21) may be a plating layer (21) made of a metal capable of forming strong bonding with both Cu and Al. Preferably, the plating layer (21) may be an Ag plating layer (21) made of Ag capable of forming strong bonding with both Cu and Al. And the bonding layer (30) may be an Ag-based sintered body containing metal particles, i.e., Ag particles, which have the same main component as the Ag-based Ag plating layer (21).

[0051] The Ag-based sintered body may be provided in the form of a film, or may be formed by applying Ag paste to the lower surface of the lower metal layer (16) or the upper surface of the plating layer (21) and then drying it. When the bonding layer (30) is an Ag sintered body film, the ceramic substrate (10) and the heat sink (20) can be thermally and mechanically bonded by placing the Ag sintered body film between the lower metal layer (16) of the ceramic substrate (10) and the heat sink (20) and then applying heat and pressure through pressure sintering.

[0052] As such, the sintering bonding method using an Ag sintered film allows for bonding at relatively lower pressure and lower temperature compared to general brazing bonding. This prevents thermal deformation of the ceramic substrate (10) and provides excellent bonding strength of approximately 80 MPa. Additionally, if the bonding layer (30) is made of an Ag-based sintered body, the bonding strength is greatly improved through diffusion and melting reactions with the Ag plating layer (21) during the sintering process, and stable bonding performance can be maintained even at high temperatures.

[0053] In some cases, the ceramic substrate (10) and the heat sink (20) may be temporarily bonded through thermochemical bonding and then finally bonded through Ag Sintering. At this time, the thermochemical bonding may include bonding methods using thermal fusion, adhesives, adhesives, etc., and the temperature of Ag Sintering may vary depending on the additives (flux, binder, etc.) included in the sintering material, but in the case of the present invention, it is preferably between 400 and 600°C.

[0054] In the example, the thickness of the bonding layer (30) made of an Ag-based sintered body is preferably between 0.15 mm and 0.25 mm, but is not limited thereto.

[0055] Although not shown in the drawing, when setting the total volume of the heat sink (20), the volume of the upper electrode (not shown) bonded to the upper metal layer (14) of the ceramic substrate (10) is calculated, and the heat sink (20) is designed in a form separated into multiple parts to have a constant volume corresponding to the volume of the upper electrode, thereby effectively suppressing the bending of the ceramic substrate unit (1) that occurs at high temperatures.

[0056] Here, it is preferable to design the volume ratio of the total volume of the upper electrode to the total volume of the heat sink (20) to be within the range of 0.9 to 1.1. In particular, if the volume ratio is designed to be close to 1.0, the volume balance between the upper and lower parts of the substrate unit (1) is maintained, thereby more effectively suppressing warping that occurs at high temperatures. For reference, the total volume can be calculated as the product of the total area and the thickness.

[0057] According to this, the problem of difficulty in suppressing bending due to the limitation of changing the thickness of the upper electrode (not shown) and heat sink (20) bonded to the upper metal layer (14) can be resolved. That is, by designing the heat sink (20) to be separated into multiple parts by etching it appropriately in the thickness direction, the high-temperature bending phenomenon can be suppressed by controlling the volume ratio of the upper electrode and the heat sink (20) to be within a specific range without changing the thickness of the heat sink (20).

[0058] FIGS. 3 and FIGS. 4 are drawings illustrating a method for manufacturing a ceramic substrate unit for a power module according to an embodiment of the present invention described above. FIGS. 3 is a flowchart illustrating a method for manufacturing a ceramic substrate unit for a power module, and FIGS. 4 is a schematic diagram illustrating a substrate manufacturing process by the method for manufacturing a ceramic substrate for a power module.

[0059] Referring to FIGS. 3 and 4, a method for manufacturing a ceramic substrate unit according to an embodiment includes the step of preparing a ceramic substrate (S100) and the step of bonding a heat sink to the lower part of the ceramic substrate (S200).

[0060] In the step of bonding the heat sink (S200), a plating layer (21) is formed on the upper surface of the heat sink (20) (S202), and a bonding layer (30) is placed between the lower metal layer (16) and the heat sink (20) (S204), and then the process (S206) of bonding the heat sink (20) to the lower metal layer (16) through one of sintering, brazing, or diffusion bonding may be included.

[0061] In the step (S100) of preparing a ceramic substrate, the ceramic substrate (10) may be one of an AMB (Active Metal Brazing) substrate, a DBC (Direct Bonded Copper) substrate, or a TPC (Thick Printing Copper) substrate, wherein a metal layer made of a conductive metal or a metal alloy is disposed on the upper and lower surfaces of a ceramic substrate (12) based on a ceramic substrate (12) made of an oxide-based or nitride-based ceramic material.

[0062] The ceramic substrate (12) may be composed of, for example, alumina (Al2O3), zirconia-reinforced alumina (ZTA), aluminum nitride (AlN), or silicon nitride (Si3N4). The upper metal layer (14) and the lower metal layer (16) may be formed by brazing a thin metal foil to the upper and lower surfaces of the ceramic substrate (12). These upper metal layer (14) and lower metal layer (16) may be composed of Cu, Cu alloy, ETP (Electrolytic Tough Pitch), or OFC (Oxygen-Free Copper).

[0063] The upper metal layer (14) can be formed in the shape of a predetermined circuit pattern. For example, the upper metal layer (14) can be formed by brazing a thin metal foil in the shape of a flat plate onto the upper surface of a ceramic substrate (12), and then processing it into an electrode pattern suitable for mounting a semiconductor chip or driving element through an etching process. The lower metal layer (16) can be formed through a process of brazing a thin metal foil in the shape of a flat plate onto the lower surface of a ceramic substrate (12).

[0064] A heat sink (20) bonded to the lower part of a ceramic substrate (10) may be made of a metal or metal alloy having a lower melting point and higher corrosion resistance than the lower metal layer (16), and having excellent thermal conductivity. For example, the heat sink (20) may be made of Al or an Al alloy. Alternatively, it may be made of an aluminum-based composite material. The aluminum-based composite material may be, for example, AlSiC, but is not limited thereto.

[0065] In the step of bonding the heat sink (S200), when forming a plating layer (21) on the upper surface of the heat sink (20) (S202), the plating layer (21) can be formed on the upper surface of the heat sink (20) with a predetermined thickness through vacuum deposition. In the process (S202) of forming the plating layer (21) on the upper surface of the heat sink (20), the plating layer (21) can be formed on the upper surface of the heat sink (20) with a thickness thinner than the bonding layer (30), for example, by vacuum deposition sputtering. In some cases, the plating layer (21) can be formed by methods such as paste application or foil attachment.

[0066] In the step (S200) of bonding the heat sink, the bonding layer (30) is placed between the lower metal layer (16) and the heat sink (20), more specifically, between the lower metal layer (16) and the plating layer (21) of the heat sink (20). This bonding layer (30) serves to thermally and mechanically bond the ceramic substrate (10) and the heat sink (20) by fusion with the plating layer (21). In the embodiment, the bonding layer (30) may include metal particles that are chemically and mechanically compatible with the plating layer (21).

[0067] In the manufacturing method according to the embodiment, a plating layer (21) made of a metal capable of forming strong bonding with both Cu and Al can be formed. The plating layer (21) may preferably be an Ag plating layer (21) made of Ag capable of forming strong bonding with both Cu and Al. And the bonding layer (30) may be an Ag-based sintered body containing metal particles, i.e., Ag particles, which have the same main component as the Ag plating layer (21).

[0068] The Ag-based sintered body may be provided in the form of a film. The Ag-based sintered body may also be formed by applying an Ag paste to the lower surface of the lower metal layer (16) or the upper surface of the plating layer (21) and then drying it. When the bonding layer (30) is an Ag sintered body film, the Ag sintered body film may be placed between the lower metal layer (16) of the ceramic substrate (10) and the heat sink (20), and then pressure sintering may be performed by applying heat and pressure to firmly bond the ceramic substrate (10) and the heat sink (20).

[0069] The sintering bonding method using an Ag sintered film allows bonding to be performed at relatively lower pressure and lower temperature compared to general brazing bonding. Therefore, thermal deformation of the ceramic substrate (10) can be prevented, and the bonding strength is excellent at approximately 80 MPa. In addition, the bonding strength is greatly improved by diffusion and melting reactions with the Ag plating layer (21) during the sintering process, and stable bonding performance can be maintained even at high temperatures.

[0070] In some cases, the ceramic substrate (10) and the heat sink (20) may be temporarily bonded through thermochemical bonding and then finally bonded through Ag Sintering. At this time, the thermochemical bonding may include bonding methods using thermal fusion, adhesives, adhesives, etc., and the temperature of Ag Sintering may vary depending on the additives (flux, binder, etc.) included in the sintering material, but in the case of the present invention, it is preferably between 400 and 600°C.

[0071] According to the above embodiment of the present invention, by attaching a heat sink to a ceramic substrate, the heat dissipation characteristics required for a power module that processes high voltage and high current signals can be satisfied. In particular, since it is bonded to the ceramic substrate through Ag Sintering, it possesses robust bonding strength and excellent thermal conductivity even in high-temperature environments. As a result, a high-power module capable of stable and highly reliable power transmission even in high voltage and high current environments can be realized.

[0072] In addition, by adopting a configuration in which an air-cooled or water-cooled heatsink, composed of one of the Micro Channel, Pin Fin, Micro Jet, or Slit types, is directly bonded to one side of a ceramic substrate, multiple layers of cooling materials can be eliminated. Through this, cost reduction and improved mass production capabilities resulting from process reduction can be expected.

[0073] The ceramic substrate unit according to this embodiment of the present invention can be applied to various devices requiring high power and high heat dissipation characteristics, in addition to single-sided or double-sided cooling power modules.

[0074] 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.

[0075] 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. As a ceramic substrate unit for a power module, A ceramic substrate comprising a ceramic substrate and a metal layer disposed on the upper and lower surfaces of the ceramic substrate; A heatsink bonded to a lower metal layer of the ceramic substrate and having a plating layer formed on its upper surface; and A bonding layer disposed between the lower metal layer and the heat sink; comprising, The bonding layer comprises metal particles that are chemically and mechanically compatible with the plating layer, and A ceramic substrate unit for a power module, wherein the plating layer and the bonding layer provide thermal and mechanical bonding functions between the ceramic substrate and the heat sink.

2. In Paragraph 1, The above heat sink is a ceramic substrate unit for a power module composed of a metal or metal alloy having a lower melting point and higher corrosion resistance than the lower metal layer.

3. In Paragraph 1, A ceramic substrate unit for a power module, wherein the lower metal layer is formed from one of the following materials: Cu, Cu alloy, ETP (Electrolytic Tough Pitch), or OFC (Oxygen-Free Copper).

4. In Paragraph 1, The above heatsink is a ceramic substrate unit for a power module made of Al or an Al alloy.

5. In Paragraph 1, A ceramic substrate unit for a power module, wherein the bonding layer comprises metal particles having the same main components as the plating layer.

6. In Paragraph 1, The above plating layer is an Ag plating layer, and A ceramic substrate unit for a power module, wherein the bonding layer comprises Ag particles identical to those of the plating layer.

7. A method for manufacturing a ceramic substrate unit for a power module, A step of preparing a ceramic substrate having metal layers provided on the upper and lower surfaces of the ceramic substrate; and The method includes the step of bonding a heatsink to the lower metal layer of the ceramic substrate; In the step of bonding the above heatsink, A plating layer is formed on the upper surface of the above heatsink, and After placing a bonding layer between the lower metal layer and the heat sink, The heat sink is bonded to the lower metal layer through one of the methods of sintering, brazing, or diffusion bonding, and A method for manufacturing a ceramic substrate unit for a power module, wherein the bonding layer comprises metal particles that are chemically and mechanically compatible with the plating layer.

8. In Paragraph 7, A method for manufacturing a ceramic substrate unit for a power module, wherein the lower metal layer is formed from one of the following materials: Cu, Cu alloy, ETP (Electrolytic Tough Pitch), or OFC (Oxygen-Free Copper).

9. In Paragraph 7, A method for manufacturing a ceramic substrate unit for a power module, wherein the heatsink is composed of Al or an Al alloy.

10. In Paragraph 7, The above plating layer is an Ag plating layer, and A method for manufacturing a ceramic substrate unit for a power module, wherein the bonding layer is an Ag-based film-type sintered body containing Ag particles.

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