DE102013113736A1 - Method for producing a metal-ceramic substrate and metal-ceramic substrate - Google Patents

Abstract

The invention relates to a method for producing a metal-ceramic substrate (1) comprising at least one ceramic layer (2) having a top and bottom (2.1, 2.2) and at least one metallization (3, 4), in which the top and / or underside (2.1, 2.2) of the at least one ceramic layer (2) with a metal or a metal alloy by means of a cold gas spraying process is coated such that a metallization (3, 4) on the top and / or bottom (2.1, 2.2) of at least one ceramic layer (2) is formed and that the with the at least one metallization (3, 4) coated ceramic layer (2) in a treatment chamber (5) at a gas pressure (P) between 500 and 2000 bar and a treatment temperature (T) between 300 ° C is treated to 1000 ° C by means of a hot isostatic pressing process.

Description

The invention relates to a method for producing a metal-ceramic substrate and a metal-ceramic substrate produced by this method.

Metal-ceramic substrates in the form of printed circuit boards consisting of a ceramic layer and at least one metallization connected to a surface side of the ceramic layer and structured to form printed conductors, contacts, contact surfaces or connection surfaces are known in various designs. Such metal-ceramic substrates find use, for example, in the construction of power semiconductor modules, i. are intended for higher operating voltages, namely 600 V and more. One of the requirements for such power semiconductor modules is a sufficiently high partial discharge resistance, whereby metal-ceramic substrates must meet this requirement. Furthermore, it is desirable to obtain a reliable high adhesion bond of the metallization with at least one of the surface sides of the ceramic layer.

• – Oxidieren einer Kupferfolie derart, dass sich eine gleichmäßige Kupferoxidschicht ergibt;
• – Auflegen der Kupferfolie mit der gleichmäßigen Kupferoxidschicht auf die Keramikschicht;
• – Erhitzen des Verbundes auf eine Prozesstemperatur zwischen etwa 1025 bis 1083°C, beispielsweise auf ca. 1071°C;
• – Abkühlen auf Raumtemperatur.

For joining metallization forming metal foils or metal layers with each other or with a ceramic substrate or a ceramic layer, for example, the so-called "DCB method"("Direct Copper Bonding") is known. Here, metal layers, preferably copper layers or foils are connected to each other and / or with a ceramic layer, using metal or copper sheets or metal or copper foils, on their surface sides of a layer or a coating ("reflow layer") a chemical compound of the metal and a reactive gas, preferably oxygen. In this example, in the US-PS 37 44 120 or in the DE-PS 23 19 854 described method, this layer or coating ("reflow layer") forms a eutectic having a melting temperature below the melting temperature of the metal (eg copper), so that by laying the metal or copper foil on the ceramic layer and by heating all the layers are joined together can, by melting the metal layer or copper layer substantially only in the region of the Aufschmelzschicht or oxide layer. Such a DCB method then has, for example, the following method steps:

• - Oxidizing a copper foil such that a uniform copper oxide layer results;
• - placing the copper foil with the uniform copper oxide layer on the ceramic layer;
• - Heating the composite to a process temperature between about 1025 to 1083 ° C, for example, to about 1071 ° C;
• - Cool to room temperature.

A disadvantage of the DCB method is that process-related defects can occur between the respective copper layer and the ceramic layer. Although these defects hardly affect the thermal properties of a metal-ceramic substrate produced by using the DCB method, there is a deterioration in the partial discharge resistance of the power semiconductor module produced therefrom due to the defects.

Furthermore, from the publications DE 22 13 115 and EP-A-153 618 the so-called active soldering method for joining metallization-forming metal layers or metal foils, in particular also of copper layers or copper foils with a ceramic material or a ceramic layer. In this method, which is also used specifically for the production of metal-ceramic substrates, at a temperature between about 800-1000 ° C, a connection between a metal foil, such as copper foil, and a ceramic substrate, such as an aluminum nitride ceramic, under Use of a brazing alloy, which also contains an active metal in addition to a main component such as copper, silver and / or gold. This active metal, which is, for example, at least one element of the group Hf, Ti, Zr, Nb, Ce, establishes a bond between the braze and the ceramic by a chemical reaction, while the bond between the braze and the metal forms a metallic braze joint is. However, the disadvantage is that the required brazing material is very cost-intensive and the structuring of the metallization applied by means of an active brazing process is technically complex.

From the EP 1 716 624 B1 is already a method for producing a stack of a plurality of metal plates to form a cooler, in which a plurality of thin metal plates or metal foils are joined together to form a stack, which then form a cooler, in particular a micro-cooler. To avoid the formation of micro-shrinkers in the transition region between the metal plates, a post-treatment of the plate stack takes place in a protective gas atmosphere at a high treatment temperature below the bonding temperature and at a high gas pressure in the range between 200 and 2000 bar. This post-treatment is also referred to as hot isostatic pressing ("HIP process"). By applying the plate stack with high gas pressure in the inert gas atmosphere at the temperature conditions mentioned leads, inter alia, that the Connection between the plates is largely free from micro-shrinkage, ie recesses or cavities in the connection region of two metal plates do not exist. As a protective gas find here nitrogen, argon or other inert or noble gases application. The treatment temperature is set such that a diffusion-welded connection is formed between the adjoining surfaces of the metal plates.

From the EP 1 774 841 B1 For example, a method for producing a metal-ceramic substrate is known in which a copper layer is applied on at least one surface side of a ceramic layer using the DCB method. Here, in a subsequent process step, the metal-ceramic substrate is subjected to a gas pressure in the range of 400-2000 bar and post-treated at an after-treatment temperature in the range between 450 and 1060 ° C. To avoid defects or micro-shrinkage in the region of the metal-ceramic transition after the DCB process, the substrate is in a closed pressure chamber in a protective gas atmosphere, such as argon atmosphere by heating to a temperature of about 560 ° C at a pressure of about 1100 bar subjected to the aftertreatment described. As a result, the connection of the copper metallization is increased to the ceramic layer and significantly reduces the formation of defects.

For coating a substrate with a metallization various thermal spraying techniques, in particular the so-called cold gas spraying are known, the bases of which, for example, in the EP 0 484 533 B1 are described. In cold gas spraying, metallic spray particles are preferably injected into a cold carrier gas stream having a gas temperature below 800 ° C., and the carrier gas stream laden with the spray particles is subsequently expanded via a nozzle. As a result, the carrier gas flow with the spray particles is accelerated to a velocity exceeding the speed of sound, which subsequently impinges on a surface of the substrate to be coated. Advantageously, the spray particles are not melted in the cold gas spraying, but upon impact with the surface to be coated results in a mechanical clamping, cold welding and / or various Reibschweißprozesse with the surface of the substrate to be coated, resulting in a layer structure. The metallic coating and the surface of the substrate in this case go directly into each other, and that creates a very dense metallization. However, a disadvantage of a coating of a surface side of a ceramic substrate with a metallization by means of cold gas spraying in comparison to known connection technologies, a low surface adhesion or bonding strength. Also, in cold gas spraying, inclusions may occur in the sprayed metallization, which adversely affect the properties of a metal-ceramic substrate produced in this way.

Based on the above-mentioned prior art, the present invention seeks to provide a method for producing a metal-ceramic substrate, which allows at least one inclusion-free metallization with high, uniformly distributed adhesive force or bonding strength. The object is achieved by a method according to claim 1 and a ceramic substrate produced according to this method according to claim 16.

The essential aspect of the method according to the invention can be seen in that the top and / or bottom of the at least one ceramic layer is coated with a metal or a metal alloy by means of cold gas spraying such that a metallization on the top and / or bottom of the at least one ceramic layer arises and that the coated with at least one metallization ceramic layer is post-treated at a gas pressure between 500 and 2000 bar and a treatment temperature between 300 ° C to 1000 ° C, by means of a hot isostatic pressing method. As a result, the bonding strength or the adhesive force of the at least one metallization produced by means of cold gas spraying on the ceramic layer is increased and, moreover, the generation of imperfections or so-called voids, in particular micro-shrinkers, is considerably reduced. Further advantageously, by means of cold gas spraying and a post-treatment by means of hot isostatic pressing in comparison to the DCB connection technology metallizations with a smaller layer thickness of about 50-200 microns are applied to a ceramic layer. With further advantage, the particle sizes in the HIP process can also be adjusted in comparison to the DCB process. By means of cold gas spraying, for example, a metallization can be produced with a layer thickness of up to 300 microns.

In a preferred embodiment, by means of the cold gas spraying method, a closed outer pore-containing, i. preferably produces gas-tight metallization. In the sense of the invention, a gas-tight metallization is understood to mean a metallization having a surface with closed pores. This is particularly well suited for a post-treatment by means of a HIP process, since by means of the HIP process preferably fully enclosed voids or voids can be effectively compressed.

In order to avoid open, ie outer pores of the metallization, at least to be able to reduce, particularly advantageous by means of cold gas spraying applied metallization of a diffusion treatment or a sintering treatment, preferably before carrying out the aftertreatment by means of a HIP process.

In a preferred embodiment variant, the diffusion treatment of the ceramic layer coated with at least one metallization is carried out in a vacuum atmosphere or in an oxygen atmosphere or in an inert gas atmosphere, preferably an argon atmosphere. Advantageously, this further improves the bonding strength or the adhesion between the metallization and the ceramic layer.

In one embodiment variant, the upper side of the ceramic layer is provided with a first metallization and the underside of the ceramic layer with a second metallization, wherein structuring and / or multiple recesses of different shape and / or depth are introduced into the second metallization to increase the metallization surface. Alternatively or additionally, a structuring and / or a plurality of recesses of different shape and / or depth can be introduced into the top side or the bottom side of the ceramic layer before coating with the metal or a metal alloy by means of the cold gas spraying method for enlarging the ceramic surface.

Further advantageously, at least one metallization is made of copper or a copper alloy, wherein the coated with copper or a copper alloy ceramic layer is post-treated at a treatment temperature between 800 ° C and 1000 ° C. For example, the ceramic layer can be coated with a copper layer or with a copper alloy layer by means of a direct copper bonding method for producing a metallization from copper or a copper alloy.

Alternatively or additionally, the at least one metallization is made of aluminum or an aluminum alloy, wherein the ceramic layer coated with aluminum or an aluminum alloy is after-treated at a treatment temperature between 400 ° C and 600 ° C. For example, to produce the metallization from aluminum or an aluminum alloy, the ceramic layer can be coated with an aluminum layer or with an aluminum alloy layer by means of a soldering process, in particular an active soldering process.

The ceramic layer is made of an oxide, nitride or carbide ceramic such as alumina (Al 2 O 3) or aluminum nitride (AlN) or silicon nitride (Si 3 N 4) or silicon carbide (SiC) or alumina with zirconia (Al 2 O 3 + ZrO 2).

Likewise provided by the present invention is a metal-ceramic substrate produced by the process according to the invention, comprising at least one ceramic layer whose top and bottom are provided with at least one metallization bonded to the invention.

The expressions "approximately", "substantially" or "approximately" in the context of the invention mean deviations from the respective exact value by +/- 10%, preferably by +/- 5% and / or deviations in the form of changes insignificant for the function ,

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and from the figures. In this case, all described and / or illustrated features alone or in any combination are fundamentally the subject of the invention, regardless of their summary in the claims or their dependency. Also, the content of the claims is made an integral part of the description.

The invention will be explained in more detail below with reference to the figures of exemplary embodiments. Show it:

1 a simplified schematic sectional view through an uncoated ceramic layer,

2 FIG. 2 a schematic side view of a coating of the upper side of the ceramic layer produced by means of a cold gas spraying process, FIG.

3 a metal-ceramic substrate produced by the method according to the invention,

4 an alternative embodiment of a metal-ceramic substrate produced by the method according to the invention and

5 an alternative embodiment of a metal-ceramic substrate produced by means of the method according to the invention comprising at least one further, further metallization applied to the metallization produced according to the invention.

1 shows a simplified schematic representation of a section through an uncoated ceramic layer 2 which is a carrier substrate for at least one metallization 3 . 4 for producing a metal-ceramic substrate 1 forms.

The ceramic layer 2 For example, it is made of an oxide, nitride or carbide ceramic such as alumina (Al 2 O 3) or aluminum nitride (AlN) or silicon nitride (Si 3 N 4) or silicon carbide (SiC) or alumina with zirconia (Al 2 O 3 + ZrO 2) and has a layer thickness of, for example, 50 Microns and 1000 microns, preferably between 200 microns and 700 microns.

The ceramic layer 2 has a top 2.1 and a bottom 2.2 on, which by means of the inventive method for producing a metal-ceramic substrate 1 with at least one metallization 3 . 4 be provided. Preferably, the top is 2.1 with at least a first metallization 3 and the bottom 2.2 with at least one second metallization 4 Mistake. The metallizations 3 . 4 For this purpose, preferably directly flat with the top or bottom 2.1 . 2.2 the ceramic layer 2 connected.

The metallizations 3 . 4 can be made of the same or different metal (s) or a metal alloy or metal alloys and have the surface enlargement structuring and / or a plurality of recesses of different shape and depth.

Coating the top and / or bottom 2.1 . 2.2 the ceramic layer 2 According to the invention, the respective metal and / or the metal alloy are injected by means of a cold gas spraying process known per se, in which metallic spray particles are injected into a cold carrier gas stream TS having a gas temperature below 800 ° C. and the carrier gas stream TS laden with the spray particles is then expanded via a nozzle arrangement D. ,

In 2 is an example above the ceramic layer 2 arranged nozzle assembly D shown. This can either be along a parallel to the top 2.1 the ceramic layer 2 extending plane or at a predetermined angle to the top 2.1 the ceramic layer 2 be moved, wherein the nozzle assembly D to produce a preferably uniform coating over the top 2.1 the ceramic layer 2 is trained. Indicates the top to be coated 2.1 the ceramic layer 2 or an optionally already by an alternative coating method applied metallization (not shown in the figures) on a surface enlarging structuring, the nozzle assembly D and the loaded with the spray particles carrier gas stream TS the respective surface course tracked such that the carrier gas flow TS at least approximately perpendicular to it. Also, a preferably steeper angle of impact can be set.

This will be the top 2.1 the ceramic layer 2 surface loaded with the loaded with spray particles carrier gas stream TS. The carrier gas flow TS has a speed exceeding the speed of sound when leaving the nozzle arrangement D. The thus accelerated spray particles hit the top 2.1 the ceramic layer 2 on, whereby a mechanical clamping and / or a cold welding with the top 2.1 the ceramic layer 2 he follows. This results in a layer structure or a first metallization 3 on the top 2.1 the ceramic layer 2 , Analogously, the second metallization 4 on the bottom 2.1 the ceramic layer 2 be generated. A disadvantage is the first and / or second metallization produced by means of the cold gas spraying process 3 . 4 at least in sections not sufficiently firmly on the ceramic layer 2 Tethered and / or there are unwanted inclusions, and so-called voids or micro-slots in the metallizations 3 . 4 , Possibly. may also have open, outer pores on the surface of the metallizations 3 . 4 to be available.

This is where the invention comes in and proposes an improved process for producing a metal-ceramic substrate 1 in front. The direct surface connection between at least one metallization produced by means of the cold gas spraying process 3 . 4 and the top and / or bottom 2.1 . 2.2 the ceramic layer 2 is reinforced according to the invention by applying a pressure-induced aftertreatment process, namely the hot isostatic pressing process ("HIP process"). For this purpose, the with the at least one metallization 3 . 4 coated ceramic layer 2 in a treatment room 5 at a gas pressure P between 500 and 2000 bar and a treatment temperature T between 300 ° C to 1000 ° C by means of a hot isostatic pressing process aftertreated. As a result, the connection of the at least one metallization produced by means of cold gas spraying becomes advantageous 3 . 4 at the top and / or bottom 2.1 . 2.2 the ceramic layer significantly improved and existing inclusions in the metallization 3 . 4 removed or dissolved. Also, the combination of the cold gas spraying process and the hot isostatic pressing process can significantly thinner metallizations compared to the known bonding technologies, such as the DCB technology 3 . 4 be prepared, for example, with a minimum layer thickness from about 50 microns.

3 shows, for example, based on a schematic diagram of a principle in the treatment room 5 recorded ceramic layer 2 whose top 2.1 with a first metallization 3 and its bottom 2.2 with a second metallization 4 are coated. In the treatment room 5 There is a gas or treatment pressure P between 500 and 2000 bar and a treatment temperature T between 300 ° C to 1000 ° C.

The basic mode of operation of the hot isostatic pressing process or so-called HIP process or HIP process is known. The preferably applied flat on the layers to be treated pressure P is generated here by means of a gas or fluid. Advantageously, when using the HIP process for the aftertreatment of a flat connection between the metallizations produced by cold gas spraying 3 . 4 and the ceramic layer 2 Compared to the other known bonding methods, the layer thickness can be reduced, in particular metal layers of a thickness of 50 micrometers and more can be processed. Advantageously, have the after-treatment of the invention, cold gas injection metallizations 3 . 4 no voids or micro-slots on. By means of cold gas spraying, for example, a metallization 3 . 4 producible with a layer thickness of up to 300 microns.

Also can be on the top or bottom 2.1 . 2.2 the ceramic layer 2 Before performing the coating by cold gas spraying already a metallization (not shown in the figures) may be present, which was applied for example by an alternative compound or Beschichtungsverfahre. For example, such a metallization can be made by a direct copper bonding method or a soldering method, in particular an active soldering method. For example, the first metallization 3 by means of cold gas spraying directly on the top 2.1 the ceramic layer 2 be applied and the at least one further metallization having underside 2.2 mittelos cold gas spraying with the second metallization 4 be provided.

The metallizations 3 . 4 For example, they may be made of copper or a copper alloy or aluminum or an aluminum alloy. The layer thickness of the metallizations 3 . 4 is at least 20 microns, preferably between 20 and 900 microns. It is understood that other suitable metals for making the metallizations 3 . 4 Application can be found. A metallization made of copper or a copper alloy 3 . 4 is preferably at a treatment temperature T between 700 ° C and 1000 ° C and a metallization made of aluminum or an aluminum alloy 3 . 4 aftertreated at a treatment temperature T between 400 ° C and 600 ° C by performing the HIP process. For the production of a metallization 4 made of copper or a copper alloy, the direct copper bonding method can be used. A production of a metallization 4 made of aluminum or an aluminum alloy, for example, using a soldering process, in particular an active soldering process.

In cold gas spraying, metallization can occur with occasionally open, outer pores. To an optimal for the implementation of the HIP process, namely gas-tight metallization 3 . 4 to obtain the applied by means of cold gas spraying metallizations 3 . 4 before the HIP post-treatment to undergo a further post-treatment, namely a diffusion aftertreatment or a sintering after treatment. This will ensure that the outer, open pores of the cold gas-sprayed metallizations 3 . 4 be closed and thus an outer gas-tight surface of the metallization 3 . 4 is present, which is exposed to the treatment pressure P in the context of HIP after-treatment.

The diffusion aftertreatment with the at least one metallization 3 . 4 coated ceramic layer 2 can be carried out in a vacuum atmosphere. Alternatively or additionally, the with at least one metallization 3 . 4 coated ceramic layer 2 be post-diffusion treated in an oxygen atmosphere. Also, a diffusion aftertreatment is that with at least one metallization 3 . 4 coated ceramic layer 2 in an inert gas atmosphere, preferably an argon atmosphere imaginable.

To increase the metallization surface, for example, the second metallization 4 this is structured and / or several recesses of different shape and depth introduced. 4 shows, for example, a metal-ceramic substrate 1 with a second metallization 4 whose metallization surface has, for example, a plurality of round, preferably circular or oval depressions. It is understood that a plurality of different recesses are providable in order to achieve an enlargement of the metallization surface, for example line-like, wave-like, diamond-shaped, slot-like and / or punctiform depressions, which are preferably uniformly distributed over the metallization surface.

Alternatively, before coating the top or bottom 2.1 . 2.2 the ceramic layer 2 be introduced directly into this one surface enlarging structuring, for example in the form of likewise line-like, wave-like, diamond-shaped, slot-like and / or punctiform depressions, which are preferably distributed uniformly over the respective ceramic surface. Also, a surface-enlarging structuring on the metallizations produced by cold gas spraying 3 . 4 be generated in the context of the Kaltgasspritzverfahrens, by a corresponding variation the layer thickness of the metallizations produced by cold gas spraying 3 . 4 , The Oberflächenvergrößernde structuring can also by applying a further metallization on the top or bottom 2.1 . 2.2 the ceramic layer 2 carried out, for example, by means of the direct copper bonding method or a soldering process, in particular an active soldering with the ceramic layer 2 is then connected and then structured by means of per se known processing methods, such as etching or lasers, before the coating by means of the cold gas spraying process with a metal or a metal alloy.

Also, the formation of an oxide layer by pretreatment of the ceramic layer 2 be effectively supported, for example, by applying an auxiliary layer by means of a chemical process. In this chemical process is on at least one top 2.1 the ceramic layer 2 , in particular an AlN substrate for producing the auxiliary layer, a layer of copper, copper oxide or other copper-containing compounds applied. The application of this auxiliary layer may be accomplished using alternative methods. Copper, copper oxide or other copper-containing compounds can be applied, for example, by means of sputtering processes, electroless deposition of copper with a commercially available bath, vapor deposition, screen printing, immersion in solutions, etc. Subsequently, the ceramic layer 2 , In particular, the AlN substrate subjected to an oxidation process by means of which copper, copper oxide or other copper compounds are oxidized.

In particular, when using an aluminum nitride ceramic layer 2 for the production of the metal-ceramic substrate 1 the mechanical gearing created when carrying out the HIP pressing process already has sufficient adhesive strength, ie on the surface of the aluminum nitride ceramic layer 2 Due to the ambient oxygen itself, an oxide layer is already formed, which is sufficient to produce an adhesive bond.

When using a silicon nitride ceramic layer 2 Also, no pretreatment to produce an oxide layer is necessary. The ambient oxygen is sufficient to give rise to a silicon oxide layer which is advantageous for the bonding process.

In a further embodiment, the first metallization 3 made of copper or a copper alloy and the second metallization 4 made of aluminum or an aluminum alloy, which are applied by means of the method according to the invention on the ceramic layer or on any existing further metallization. Alternatively, the first metallization 3 made of aluminum or an aluminum alloy and the second metallization 4 be made of copper or a copper alloy.

In one embodiment of the method according to the invention is one of the metallizations 3 produced by cold gas spraying, whereas the further metallization 4 before the hot isostatic pressing using a direct copper bonding method or a soldering process, in particular a brazing or Aktivlotverfahrens with the ceramic layer 2 is connected directly flat.

Also can on the metallizations generated by cold gas spraying 3 . 4 before the HIP aftertreatment, a further metallization layer can be applied, for example by electrodeposition or externally electroless deposition. The layer thickness of such a further metallization layer is for example between 2 and 40 micrometers. This can advantageously open, outer pores in the metallizations produced by cold gas spraying 3 . 4 getting closed. The further metallization layer can be made, for example, from copper, a copper alloy, silver, nickel or aluminum or an aluminum alloy.

In an alternative embodiment according to 5 may be the first and / or second metallizations 3 . 4 with at least one further metallization 6 . 7 be provided which either also by cold gas spraying or using an alternative bonding technology, such as a direct-copper bonding method or a Lotverfahrens, in particular brazing or Aktivlotverfahrens on the first and / or second metallization 3 . 4 is applied. In the present embodiment, the first metallization 3 with a third metallization 6 and the second metallization 4 with a fourth metallization 7 Mistake. By means of the method according to the invention can thus metal-ceramic substrates 1 be produced with almost any multilayer structure.

The invention has been described above by means of exemplary embodiments. It is understood that numerous changes and modifications are possible, without thereby departing from the invention underlying the idea of the invention.

LIST OF REFERENCE NUMBERS

1

Metal-ceramic substrate

2

ceramic layer

2.1

top

2.2

bottom

3

first metallization

4

second metallization

5

treatment room

6

third metallization

7

fourth metallization

D

nozzle assembly

P

treatment pressure

T

treatment temperature

TS

laden with particles carrier gas stream

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 3744120 [0003]
• DE 2319854 [0003]
• DE 2213115 [0005]
• EP 153618 A [0005]
• EP 1716624 B1 [0006]
• EP 1774841 B1 [0007]
• EP 0484533 B1 [0008]

Claims (16)

Method for producing a metal-ceramic substrate ( 1 ) comprising at least one ceramic layer ( 2 ) with a top and bottom ( 2.1 . 2.2 ) and at least one metallization ( 3 . 4 ), in which the top and / or bottom ( 2.1 . 2.2 ) of the at least one ceramic layer ( 2 ) is coated with a metal or a metal alloy by means of a cold gas spraying process in such a way that at least one metallization ( 3 . 4 ) on the top and / or bottom ( 2.1 . 2.2 ) of the at least one ceramic layer ( 2 ) and that with the at least one metallization ( 3 . 4 ) coated ceramic layer ( 2 ) in a treatment room ( 5 ) is post-treated at a gas pressure (P) between 500 and 2000 bar and a treatment temperature (T) between 300 ° C to 1000 ° C by means of a hot isostatic pressing process. A method according to claim 1, characterized in that by means of the cold gas spraying method, a closed outer pores having metallization ( 3 . 4 ) is produced. A method according to claim 2, characterized in that the applied by means of cold gas spraying metallization ( 3 . 4 ) is subjected to a diffusion aftertreatment or a sintering after treatment, preferably before the post-treatment by the hot isostatic pressing method. A method according to claim 3, characterized in that the diffusion treatment of the at least one metallization ( 3 . 4 ) coated ceramic layer ( 2 ) is carried out in a vacuum atmosphere, an oxygen atmosphere or an inert gas atmosphere, preferably an argon atmosphere. Method according to one of claims 1 to 4, characterized in that the top ( 2.1 ) of the ceramic layer ( 2 ) with a first metallization ( 3 ) and the underside ( 2.2 ) of the ceramic layer ( 2 ) with a second metallization ( 4 ), wherein in the second metallization ( 4 ) to increase the metallization surface structuring and / or a plurality of recesses of different shape and / or depth are introduced. Method according to one of claims 1 to 4, characterized in that in the top ( 2.1 ) or the underside ( 2.2 ) of the ceramic layer ( 2 ) before the coating with metal or a metal alloy by means of the cold gas spraying process to increase the ceramic surface, a structuring and / or a plurality of recesses of different shape and / or depth are introduced. Method according to one of claims 1 to 4, characterized in that a surface- increasing structuring of a metallization ( 3 . 4 ) is produced with a structuring depth of up to 5mm by means of the cold gas spraying process. Method according to one of claims 1 to 7, characterized in that the at least one metallization ( 3 . 4 ) is made of copper or a copper alloy. Method according to one of claims 1 to 8, characterized in that the ceramic layer ( 2 ) for producing a metallization ( 3 . 4 ) is coated from copper or a copper alloy by means of a direct copper bonding method with a copper layer or with a copper alloy layer. A method according to claim 8 or 9, characterized in that the coated with copper or a copper alloy ceramic layer ( 2 ) is post-treated at a treatment temperature (T) between 700 ° C and 1000 ° C. Method according to one of claims 1 to 10, characterized in that the at least one metallization ( 3 . 4 ) is made of aluminum or an aluminum alloy. Method according to one of claims 1 to 11, characterized in that the ceramic layer ( 2 ) is coated with an aluminum layer or with an aluminum alloy layer by means of a soldering process, in particular an active soldering process, to produce an aluminum or an aluminum alloy. A method according to claim 11 or 12, characterized in that the coated with aluminum or an aluminum alloy ceramic layer ( 2 ) is post-treated at a treatment temperature (T) between 400 ° C and 600 ° C. Method according to one of claims 1 to 13, characterized in that the ceramic layer ( 2 ) is made of an oxide, nitride or carbide ceramic such as alumina (Al 2 O 3) or aluminum nitride (AlN) or silicon nitride (Si 3 N 4) or silicon carbide (SiC) or alumina with zirconia (Al 2 O 3 + ZrO 2). Method according to one of claims 1 to 14, characterized in that a surface- increasing structuring of the metallization ( 3 . 4 ) is produced with a structuring depth of up to 5mm by cold gas spraying. Metal-ceramic substrate ( 1 ) comprising at least one ceramic layer ( 2 ) with a top and Underside ( 2.1 . 2.2 ) and at least one metallization ( 3 . 4 ) prepared by a method according to any one of the preceding claims.

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