WO2014026675A2 - Method for producing hollow bodies, particularly for coolers, hollow body and cooler containing electrical and/or electronic components - Google Patents

Abstract

Method for producing hollow bodies, particularly for coolers, with at least two metal layers arranged by stacking to create a stack and connected to one another via at least one connecting or bond layer, and with at least one cavity formed inside the stack and produced by structuring at least one metal layer, wherein a layer made of a bonding material is applied before the stack is created to at least one of the surface sides of the metal layers adjoining one another in the stack, and is formed after the stack is created into the bond layer connecting the metal layers.

Description

 Process for the production of hollow bodies, in particular of coolers, hollow bodies and coolers containing electrical or electronic assemblies

The invention relates to a process for the preparation of hollow bodies according to

The preamble of claim 1, to a hollow body, in particular radiator according to the preamble of claim 1 9 and to an assembly according to the preamble of claim 20.

For example, the so-called "DCB method" (direct copper bond technology) is known for connecting metal layers or sheets (eg copper sheets or sheets) to one another and / or to ceramic or ceramic layers, using metal sheets. or copper sheets or metal or copper foils which have on their surface sides a layer or a coating (reflow layer) of a chemical compound of the metal and a reactive gas, preferably oxygen

For example, in US-PS 37 44 120 or in DE-PS 23 1 9 854 described method, this layer or coating (reflow) forms a eutectic with a melting temperature below the melting temperature of the metal (eg copper), so that by placing the film on the ceramic and by heating all the layers they can be connected to each other, namely by melting the metal or copper in W1 genentlich only in the region of the melting or oxide layer.

This DCB method then indicates e.g. the following process steps:

 • Oxidizing a copper foil so that a uniform copper oxide layer results;

• placing the copper foil on the ceramic layer;

 Heating the composite to a process temperature between about 1025 to 1083 ° C, e.g. to about 1071 ° C;

 • Cool to room temperature.

Analogous to this aforementioned DCB method for direct bonding of copper to copper or copper on ceramic, other direct metal bonding processes or technologies are also known with which, in an analogous manner, the joining of metal layers or sheets in general with each other and / or with ceramic or ceramic layers is possible. The DCB The method and method analogous to it will hereinafter be referred to as DMB (Direct Metal Bond) method.

Also known is the so-called active soldering method (DE 22131 1 5, EP-A-153 618), e.g. for joining metallization-forming metal layers or metal foils, in particular also copper layers or copper foils or aluminum layers or aluminum foils with ceramic material. In this method, which is also used especially 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 aluminum nitride ceramic, using a brazing filler metal, 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 chemical bond between the solder and the ceramic, while the bond between the solder and the metal is a metallic braze joint ,

Also known are hollow bodies in the form of active heat sinks or coolers consisting of a plurality of stacked metal layers or metal foils (stacking) which are formed by bonding or bonding, e.g. by soldering, diffusion bonding or by means of the DMB method are interconnected. The disadvantage here is, inter alia, that the entire stack of the metal lschichten for bonding or bonding heated to high temperature and the diffusion welding must also be additionally subjected to high pressure, whereby the structure of the metal layers at least partially changed and in particular the hardness the metal layers decreases. Furthermore, it is often not possible to prevent bonding material, such as e.g. the solder or the eutectic melt in solder joints in

Openings and / or recesses flow, which are introduced into the metal layers in the interior of the stack for the formation of cavities or cooling channels, and these openings or depressions or the cavities or cooling channels formed by these flows clogged.

Galvanic or other methods to be produced on the metal layers or metal foils corrosion protection layers can not be applied before stacking, since these layers are changed during bonding or bonding by alloying and lose their protective effect in the rule. Applying the anticorrosion coatings after the Joining is not possible or insufficiently possible. Incompletely applied

Corrosion protection coatings often even increase the corrosion by forming local electrical elements between different metals. Another disadvantage of previous methods consists in long process times, which are necessary for the joining and caused by the heating and cooling process.

The object of the invention is to provide a method which avoids the aforementioned disadvantages and simplifies the production of hollow bodies from at least two arranged in a stack and interconnected metal layers or metal foils.

To solve this problem, a method according to claim 1 is formed. A hollow body, in particular a cooler, is the subject matter of patent claim 19. An assembly with such a cooler is the subject matter of patent claim 20.

The main advantages of the method according to the invention are, inter alia:

 It is only a slight heating of the joining material, namely the metal layers or

 Metal foils required during joining or bonding.

 Because of the only slight heating during the joining or bonding process, no or substantially no changes in the material properties of the metal layers occur. Characterized in that the bonding or bonding the metal layers or foils

Bonding layers are produced by sintering or are sintered layers and there are no melting processes during the bonding process, significantly finer structures can be achieved. As a result, u.a. an enlargement of the inner surface of the respective

Cavity and thus improved heat transfer possible.

 Anticorrosive coatings can be applied prior to bonding and will not change properties due to the relatively low sintering temperature.

 The sintered material sinters only at those areas where the sintering pressure is effective and the sintering flow flows. Residual or excess and unsintered sintered material can be washed out after sintering.

Reduced process time results in a considerable reduction in production costs. If the metal layers or metal foils consist, for example, of copper or of a copper alloy, the sintering material used is preferably a metal powder made of copper or a copper alloy or a material containing this metal powder. The sintering temperature is then significantly below the melting point of the copper or copper alloy of both the metal layer and the sintered material. The same applies when using metal layers of aluminum or an aluminum alloy and a sintered material in the form of a metal powder of aluminum or an aluminum alloy or a sintered material containing this metal powder. Again, the sintering temperature is well below the melting point of the aluminum or aluminum alloy of both the metal layer and the sintered material.

Especially when using metal layers and sintered material made of aluminum or an aluminum alloy results in a significant simplification compared to conventional joining or bonding method, since the connection of the metal layers takes place without vacuum and without special flux.

For the purposes of the invention, "active coolers" are, in particular, hollow bodies whose cavities form cooling channels which contain or are traversed by a heat-transporting medium or cooling medium.

The expression "essentially" or "approximately" in the sense of the invention means deviations from the exact value by +/- 10%, preferably by +/- 5% and / or deviations in the form of changes that are 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:

Fig. 1 in a simplified representation and in section a hollow body in the form of an active cooler or an active heat sink;

 FIG. 2 is a schematic representation of various method steps of the method for producing the hollow body of FIG. 1; FIG.

 3 shows in a simplified representation and in section a hollow body in the form of an active cooler according to another embodiment of the invention;

 4 shows a schematic illustration of different method steps of the method for producing the hollow body of FIG. 3;

 5 shows in a simplified representation and in section a hollow body in the form of an active cooler according to another embodiment of the invention;

 FIG. 6 is a schematic representation of various method steps of the method for producing the hollow body of FIG. 5; FIG.

 5 shows in a simplified representation and in section a hollow body in the form of an active cooler according to another embodiment of the invention;

 FIG. 8 is a schematic representation of various method steps of the method for producing the hollow body of FIG. 7; FIG.

 9 is a schematic representation of various partial steps of the method for producing the hollow body of FIGS. 1, 3, 5 and 7 in a further embodiment of the invention; Fig. 10 and 1 1 each time the course of the sintering current Is in the manufacture of

Hollow body of Figures 1, 3, 5 and 7;

 12 shows the time profile of the sintering pressure Ps during the production of the hollow body of FIGS. 1, 3, 5 or 7.

In FIGS. 1 and 2, 1 is a hollow body in the form of a cooler. The hollow body consists of a plurality of stack-like stacked metal layers 2-5, which are each formed by metal foils and are bonded to one another via bonding layers in the form of sintered layers 6-8 by sintering. The sinter layers 6 - 8 are part of

Stack arrangement, ie in each case a sintered layer 6 - 8 is between two metal layers 2-5 arranged.

The two metal layers 2 and 5 form the outer layers and the upper and

Bottom of the hollow body 1. The arranged between the metal layers 2 and 5 metal layers 3 and 4 form cavities 9 of the hollow body 1, d. H. when using the hollow body 1 as an active cooler the flowed through by a vapor and / or gaseous or preferably by a liquid heat transport medium or cooling medium cooling structure of the radiator. The cavities or cooling erstruktur is closed at the top and bottom of the hollow body 1 by the local metal layers 2 and 5. For supplying and discharging the cooling medium are connections, which are indicated in the figure 1 schematically with 1 .1. The metal layers 3 and 4 are provided to form the cavities 9 and the radiator structure with a plurality of openings 10, of which in the illustrated embodiment, each opening 10 is continuous, d. H. from the one

Surface side to the other surface side of the metal layers 3 and 4 extends. The formation and / or arrangement of the openings 10 is basically arbitrary, provided that the required radiator structure results, preferably a cooler structure with ever-branching cooling channels and / or with continuous posts 1 .2, which connect the metal layers 2 and 5 and made of the material Metal layers 2 and 4 and the sintered layers 6 - 8 exist. The openings 10 in the metal layers 3 and 4 are produced for example by punching, cutting (also laser cutting) or by etching in an etching masking process.

FIG. 2 shows in the positions a - i the essential steps of the method for

Production of the hollow body 1. According to the positions a and b, the upper metal layer 2 is provided. Corresponding to the positions c and e, the metal layers 3 and 4 provided with the openings 10 are provided and then subsequently provided on a surface side with a layer 6.1 or 7.1 of sintered material according to the positions d and f, the sintered layer 6 after sintering later or 7 forms. The application of the layers 6.1 and 7.1 preferably takes place in such a way that the respective layer does not cover the openings 10. Corresponding to the position g, the metal layer 5 is provided and then provided according to the position h on a surface side with a layer 8.1 of the sintered material, which forms the sintered layer 8 after sintering. The individual metal layers 2-5 provided with the sintered material are stacked one above the other in accordance with the position i such that the metal layers 2-5 following one another in this stack abut each other over a layer 6.1, 7.1 or 8.1 from the sintered material. Subsequently, the stack thus formed between two electrodes 1 1 and 12 is arranged, of which the electrode 1 1 against the metal layers 3 and 4 facing away from the surface side

Metal layer 2 and the electrode 12 against the metal layers 3 and 4 facing away from the surface side of the metal layer 5 is applied, in such a way that the respective electrode 1 1 or 12 with its electrode surface, the respective metallization 2 or 5 completely covered, but preferably protrudes beyond the edge of the stack formed by the metal layers 2-5. The electrode 1 1 is for example part of a press ram of a press, for example a hydraulic press for generating a high pressure or sintering pressure Ps. The electrode 12 is then part of a workpiece support of this press.

The sintering or the formation of the metal layers 2-5 connecting and dense sintered layers 6 - 8 is carried out under sintering pressure Ps, on the electrodes 1 1 and 12 and thus on the metal layers 2-5 and the intermediate layer 6.1, 7.1 and 8.1 perpendicular to their surface sides is applied, and by a sintering current Is, which is provided by a current source 1 3, wherein the voltage between the electrodes 1 1 and 12 is low, for example in the range between 2V and 25V.

Since the metal layers 2 - 5 as well as the sintering material used for the layers 6.1, 7.1 and 8.1 are electrically conductive, the formation of the sintered layers 6 - 8 by current or Sparksintern possible, the sintering current Is is of course adjusted so that the required sintering temperature is reached will, but will not melt.

The sintered layer 8 is shown in FIGS. 1 and 2 as a continuous layer. Since, however, the sintering takes place only at those areas where the sintering pressure Ps is sufficiently effective and also the sintering flow Is flows, ie at the bottom of the

Metal layer 4 outside the openings 10, and further residual or excess and not sintered sintered material can be washed out after sintering, is the

Sintered layer 8 in the finished hollow body 1 also structured, i. not present at the openings 10 of the metal layer 4 or only with reduced thickness.

FIG. 3 again shows, in section, a hollow body 1 a, which differs from the hollow body 1 essentially only in that the sintered layer 8 connecting the lower metal layer 5 to the overlying metal layer 4 is structured by already structured application of the layer 8 the cavities 9 at the of the

Metal layer 5 formed underside of the hollow body 1 a reliably not through the

Sintered layer 8 but are limited by the metal layer 5.

FIG. 4 again shows in the positions a-i the essential steps of the method for producing the hollow body 1 a, whereby this method differs from the method of FIG. 2 only in that according to the position h the later

Sintered layer 8 forming sintered material is already applied structured in the layer 8.1, in such a way that this material is located only where the metal layer 4 outside its openings 10 abuts against the layer 8.1. According to position i, the formation of the medium, in particular for the heat flowing through the cavities 9, is carried out by means of dense sintering layers 6 - 8 by application of the sintering pressure Ps and of the

Sinterstromes Is across the electrodes 1 1 and 12th

FIG. 5 shows, in a simplified sectional illustration as a further embodiment, a hollow body 1 b, which consists of an upper metal layer 14 and a lower metal layer 15. Both metal layers 14 and 15 are again metal foils. In order to form cavities 1 6 closed to the outside or a cooler structure through which the heat-transporting medium or cooling medium flows, the lower metallization 1 5 is provided with indentations or depressions 17. The two metal layers 14 and 15 are in turn connected to one another by a dense sinter layer 18 dense at least for the heat-transporting medium or cooling medium.

FIG. 6 shows, in the positions a-f, essential method steps in the production of the hollow body 1b. Corresponding to the positions a and b, the metal layer 14 is provided and corresponding to the positions c and d, the metal layer 1 5 with the recesses 17 is formed from a metal layer corresponding to the metal layer 14, for example by pattern etching by means of a masking-etching method. A structured layer 18.1 of sintered material forming the later sinter layer 18 is then applied to the metal layer 1 5 in accordance with the position e, in such a way that the recesses 1 7 of the sintering layer 1

Sintered material is not covered. In accordance with position f, a stack is then formed between the two metal layers 14 and 15 with the layer 18. 1 between the electrodes 1 1 and 12 and subjected to the sintering pressure P and through the stack by pressurizing the stack

Sintering current I generates the two metal layers 14 and 1 5 connecting dense sinter layer 18.

Figure 7 shows in section a hollow body 1 c, which differs from the hollow body of Figure 5 in that the metal layer 14 is provided with the recesses 1 7, in such a way that the recesses 1 7 in both metal layers 14 and 15th to the closed to the outside cavities 1 6 or to the closed to the outside radiator structure. The two metal layers 14 and 15 are in turn connected to one another via the structured, dense sintered layer 18.

FIG. 8 shows, in the positions a-g, essential method steps of the method for producing the hollow body 1c, this method differing from the method of FIG. 6 only in that, corresponding to the positions a and g, the metal layer 14 with the recesses 17 is provided.

The sintered layers 6 - 8 and 18 each extend over the entire surface of the adjacent metal layers 2 - 5, 14 and 1 5, although in the illustrated

Embodiments in any case on the metal layers 3, 4, 14 and 15, the openings 10 and recesses 1 7 are kept free.

In order to improve the sintering process and / or the sintering connection between the metal layers 2 - 5, 14 and 15 via the sintered layers 6 - 8, 18, it may be expedient to apply the respective metal layer before applying the layer 6.1, 7.1, 8.1 or 18.1 from the sintered material to be provided with a metallic intermediate layer 1 9, as in the figure 9 is exemplified for the metal layer 5 in the positions a and b. The structured or continuous layer 8.1 made of sintered material (positions c and d) is then applied to this metallic intermediate layer 19. The intermediate layer 1 9 may also be a corrosion protection layer or part of such a layer, which then extends for example over the entire exposed surface of the metal layer.

Suitable materials for the metal layers 2 - 5, 14 and 1 5 include copper, aluminum, iron, nickel, titanium, molybdenum, tungsten, tantalum, silver, gold and alloys of the aforementioned metals, such as copper alloys, iron alloys,

Silver alloys, aluminum alloys, titanium alloys, but also multi-layer materials with layers of different metals, e.g. from the aforesaid metals or metal alloys.

Suitable sintered material for the layers 6.1, 7.1, 8.1 and 18.1 is a sinterable particulate or powdered metallic material or a metal powder, for example of copper, silver, gold, aluminum, nickel, iron, titanium or alloys of the aforementioned metals, for example of copper alloys, iron alloys, silver alloys,

Aluminum alloys, tantalum alloys, but also mixtures or pastes containing the sinterable particulate or powdery metallic material or metal powder and other additives. The particle size of the sinterable particulate or powdery metallic material is, for example, in the range between 0.1 μ and 50 μ. The sintered material is present for example in monomodal, bimodal or trimodal form.

The layers 6.1, 7.1, 8.1 and 18.1 each consist of the same material in the respective method and are applied, for example, with a layer thickness in the range between 5 μιη and 300 μιη. The application of the layers 6.1, 7.1, 8.1 and 18.1 takes place, for example, in a printing process, e.g. Screen printing process, by dispensing,

Spraying / spraying, electrostatic or using applicator rollers. Other methods are possible.

For the metallic intermediate layer 19, whose metal l is made of the metal of these

Interlayer-bearing metal layers 2 - 5, 14 or 15 differs are suitable for example, copper, nickel, chromium, silver, gold, palladium, platinum or alloys of the aforementioned metals. The intermediate layer 19 can be applied in different ways, for example galvanically, by chemical deposition or by a CVD method, by sputtering, by plasma spraying, by cold gas spraying, etc. The thickness of the intermediate layer 1 9 is for example in the range between 0.05 μιη and 100 μιη.

The sintering pressure Ps used during sintering is, for example, in the range between 0.5 kN / cm ² to 6.0 kN / cm ² . The sintering current Is is preferably chosen such that the current density in the region of the sintering layers 6 - 8, 18 to be produced, ie where the sintering process takes place, is in the range between 10 A / cm ² and 300 A / cm ² .

To improve the sintering performance and achieve a sintering current Is with high

Current maxima or current peaks is furthermore, as shown in FIG. 10, the use of a pulse-shaped sintering current Is, wherein the pulse width t1 of the respective current pulse lies in the range between 1 msec and 500 msec and the pulse interval t2 is in the range between 0 msec and 400 msec. It may also be appropriate according to the Figure 1 1, to superimpose the current pulses in addition with an alternating current or with smaller current pulses.

In order to improve the formation of the sintered layers 6 - 8 and 18, it is also expedient that the sintering pressure Ps is also impulsively applied, specifically in accordance with FIG. 12 in the form that a constant sintering pressure Psmin is superimposed on a pulse-shaped increase in the sintering pressure, so that the sintering pressure Ps changes in a pulse shape between a pressure Psmax and a value Psmin. The pressure Psmin is then for example between 0.05 Psmax and 0.98 Psmax, wherein Psmax is selected in the range between 0.5 kN / cm ² and 6 kN / cm ² . The period duration tp of the pulse-shaped pressurization is, for example, in the range between 0.5 msec and 3000 msec.

In a further embodiment of the method according to the invention, the sintering pressure Ps increases during the sintering process from a sintering pressure Psmin and reaches the value Psmax before the end of the sintering process or the sintering phase, as shown in broken lines in FIG. In this embodiment, it is also possible that a rising sintering pressure Ps is superimposed on a pulse-shaped changing sintering pressure.

Especially the increasing sintering pressure has the advantage, for example, that at the beginning of the sintering phase pre-sintering and thus at least some stabilization of the sintered material or of the sintered layers formed by this material takes place, while in the course of the sintering phase, in addition to the sintering, an increasing compression of the sintering layer Sintering material takes place so as to seal the at least for the heat-transporting medium

Sinter layers 6 - 8 and 18 to achieve.

In order to improve the flow properties of pastes made of sintered material, these preferably also contain organic additives, such as, for example, cellulose. In this case, after the application of the respective paste and before the introduction of the sintering phase, for example before or after stacking of the metal layers 2-5, 14 and 15, drying and heating of the organic additives takes place. In particular, the drying and heating of the organic additives can be carried out by electric current even when arranged between the electrodes 1 1 and 12 stacking arrangement, with appropriate adjustment of the current density and the pressure P.

The respective hollow body 1, 1 a - 1 c preferably forms an active cooler for electrical or electronic components 20, for example, for opto-electrical components, for example for diode laser bars.

The invention has been described above with reference to exemplary embodiments. It is understood that numerous changes and modifications are possible without thereby departing from the inventive idea underlying the invention.

For example, it may be expedient to heat the respective stack of the metal layers 2-5, 14 and 15 after the application of the layers 6.1-8.1, 18.1 from the sintered material in order to support the sintering process and / or when using a pasty sintered material To burn out additives, in particular organic additives, etc. List of Reference Numerals 1a-1c Hollow body

-5 metal layer

-8 sintered layer

1 -8.1 layer of sintered material

 cavity

 opening

 , 12 electrode

 power source

 , 15 metal layer

 cavity

 deepening

 sintered layer

 .1 view of sintered material

 interlayer

 electrical or electronic component

Claims

claims 1 . Method for producing hollow bodies, in particular coolers, having at least two metal layers (2-5, 14, 15) connected to one another by stacking and interconnected via at least one bonding or bonding layer (6-8, 18) and at least one metal layer a formed inside the stack cavity (9, 1 6) through Structuring of at least one metal layer (3, 4, 14, 15) is generated, wherein before Stacking on at least one of the stack each adjacent Surface side of the metal layers (2-5, 14, 1 5) a layer (6.1, 7.1, 8.1, 18.1) applied from a bonding material and after the stacking in the metal layers (2-5, 14, 1 5) connecting bonding layer is formed . characterized, in that a sintered material is used as the bonding material, and in that after stack formation in a sintering phase from the sintered material under sintering pressure (Ps) and by application of an electrical sintering current (Is), the bonding layer connecting the metal layers (2-5, 14, 15) to one another in the form of a sintered layer (6-8, 18) is produced. 2. The method according to claim 1, characterized in that at least one metal layer (3, 4) in the interior of the stack to form the at least one cavity (9) as structuring with through openings (10) is to be provided. 3. The method according to claim 1 or 2, characterized in that at least one Metallization (14, 1 5) on its one adjacent metallization (1 5, 14) side facing structuring with indentations or recesses (1 7) is to be provided. 4. The method according to any one of the preceding claims, characterized in that the application of the layer (6.1, 7.1, 8.1, 18.1) of the sintered material on the surface regions of the metal layers (2-5, 14, 1 5) outside the openings (10). and recesses (1 7) takes place. 5. The method according to any one of the preceding claims, characterized in that as metal layers (2-5, 14, 15) such of copper, aluminum, iron, titanium, molybdenum, tungsten, Tantalum, silver, gold or from the aforementioned metals containing alloys or from copper and copper alloys or aluminum and aluminum alloys. 6. The method according to any one of the preceding claims, characterized in that the sintered material is a sinterable particulate or powdery metallic material or a metal powder, for example, copper, iron, titanium, silver, gold or alloys containing the aforementioned metals, or a metal powder containing, for example, paste-like material is used. 7. The method according to any one of the preceding claims, characterized in that at least one of the respective sintered layer (6-8, 18) to be joined together metal layers (2-5, 14, 1 5) on its surface side before applying the Sintered material or the layer (6.1, 7.1, 8.1, 18.1) is provided from the sintered material with a metallic intermediate layer (1 9), for example with an intermediate layer (19) of at least one metal of the group consisting of nickel, chromium, silver, gold , Copper, platinum, palladium, and that the metallic intermediate layer (19) is applied, for example, galvanically, chemically, by spattering, by plasma spraying and / or by cold spraying. 8. The method according to claim 7, characterized in that the metallic intermediate layer is applied with a thickness in the range between 0.05 μ and 100 μ. 9. The method according to any one of the preceding claims, characterized in that the sintered material is a sinterable particulate or powdery metallic material or Metal powder is used in monomodal, bimodal or trimodal form. 10. The method according to any one of the preceding claims, characterized in that the layer (6.1, 7.1, 8.1, 18.1) is applied from the sintered material with a layer thickness in the range between 5μιη and 300μιη. 1 1. Method according to one of the preceding claims, characterized in that during the sintering phase of the stack of the metal layers (2-5, 14, 1 5) with a Sintering pressure (Ps) in the range between 0.5 kN / cm ² and 6 kN / cm ² and / or with a sintering current density between 10A / cm ² and 300A / cm ² in the region to be generated Sinter layers (6-8, 18) is acted upon. 12. The method according to any one of the preceding claims, characterized in that the stack of the metal layers (2-5, 14, 1 5) for applying the sintering pressure (Ps) and the sintering flow (Es) between two electrodes (1 1, 12) is arranged. 13. The method according to any one of the preceding claims, characterized in that the sintering pressure (Ps) is changed during the sintering phase, for example, from a lower sintering pressure (Psmin) increasing to an upper sintering pressure (Psmax) and / or pulsed with between the lower sintering pressure (Ps) Psmin) and the upper sintering pressure (Psmax) changing pressure pulses, wherein the lower sintering pressure (Psmin), for example, in the range between 5% and 98% of the upper sintering pressure (Psmax) and the duration of the pressure pulses in the range between 0.5 msec and 3000 msec is. 14. The method according to any one of the preceding claims, characterized in that the sintering pressure and the sintering flow are adjusted so that dense sintered layers (6-8, 18) result. 15. The method according to any one of the preceding claims, characterized in that the application of the sintered material or layers (6.1, 7.1, 8.1, 18.1) made of the sintered material by screen printing, dispensing, spraying, spraying and / or electrostatic. 16. The method according to any one of the preceding claims, characterized in that prior to the introduction of the sintering phase and / or during the sintering phase drying and / or heating of additives, in particular organic additives from the sintered material or the layers (6.1, 7.1, 8.1, 18.1) of the sintered material takes place, for example by Applying these views with an adapted or reduced current density and with reduced pressing pressure. 1 7. The method according to any one of the preceding claims, characterized in that after the sintering phase removal of non-sintered sintered material takes place, for example by washing. 18. The method according to any one of the preceding claims, characterized in that for further compression of the sintered layers (6-8, 18) a hot isostatic pressing of Hollow body (1, 1 a - 1 c) takes place. 19. A hollow body, in particular a cooler, consisting of at least two metal layers forming a stack (2-5, 14, 15), wherein metal layers (2-5, 14, 15) adjacent to one another in the stack each have a connection on their mutually facing surface sides. or bonding layer (6 - 8, 18) are interconnected and at least one metal layer (3, 4, 14, 1 5) in the interior of the stack to form at least one cavity (9, 16) is structured, for example by forming a plurality of openings (10) and / or impressions or depressions (1 7), characterized, the respective bonding layer (6-8, 18) comprises a metallic sintered layer Sintered material, and that the hollow body is preferably prepared according to one of the preceding claims 1-18. 20 assembly with at least one designed as a cooler hollow body (1, 1 a - 1 c) and at least one provided on the radiator electrical or electronic component (20), characterized that the hollow body (1, 1 a - 1 c) is designed according to claim 19. 21. An assembly according to claim 20, characterized in that it is an opto-electrical assembly and / or the component (20) is an opto-electrical device.