DE102014116761A1 - Method for establishing a connection between two ceramic parts, in particular parts of a pressure sensor - Google Patents

Abstract

A method of making a connection between two surfaces or surface portions of two ceramic parts comprises: providing (110) a first ceramic part and a second ceramic part; Providing (130) an active brazing material on at least a surface portion of at least one of the ceramic parts; and heating the active brazing solder in a brazing process, wherein the active brazing material is provided for bonding the first and second ceramic parts by a sputtering method (130), wherein according to the invention, when performing the sputtering process, an intermediate target is sputtered by sputtering components of the active brazing material with the active brazing material (131 ), and at least one ceramic part, preferably both ceramic parts, is coated in sections by sputtering the coated intermediate target with the active brazing solder (132).

Description

The present invention relates to a method for producing a connection between two ceramic parts, in particular parts of a pressure sensor and a ceramic product, in particular a ceramic pressure sensor.

Ceramic pressure sensors comprise a main body and a measuring diaphragm, wherein the measuring diaphragm is joined by means of an active brazing-solder. A suitable active brazing material for joining ceramic parts made of corundum is, for example, a Zr-Ni-Ti alloy, since it is compatible with corundum from its thermal expansion coefficient.

In the European patent EP 0 490 807 B1 such an active brazing material is disclosed. The patent EP 0 558 874 B1 discloses a method of making rings of such an active brazing alloy, active-magnetic brazing rings are placed between the two parts to connect the measuring membrane and the body as spacers and melted in a high vacuum brazing process, thereby forming a pressure-tight and high-strength annular connection between the two ceramic parts. An alternative to applying the solder in the form of prefabricated rings is to provide the active braze in a screen printing process. A screen-printable paste of the active braid and a method for the production thereof is disclosed in the published patent application EP 0 988 919 A1 disclosed.

However, the rings can be produced only in a minimum thickness of about 30 microns in reproducible quality and also the screen-printable paste has grain sizes, resulting in the result to joints with a minimum thickness of about 30 microns between the ceramic parts.

The desire to miniaturize pressure sensors indirectly implies the need for a thinner joint because, for example, in a ceramic pressure sensor with a capacitive transducer, miniaturization results in a reduction in the electrode area of the capacitive transducer, which then has to be compensated by decreasing the gap ,

The publication DE 10 2010 043 119 A1 discloses a method for making a bond between two surfaces or surface portions of two ceramic parts in which all of the active brazing material is provided for bonding the first and second ceramic parts such that a surface portion of one or both ceramic parts is vapor deposited with the alloy of the active brazing alloy and / or or their components are coated. The vapor deposition can be done for example by sputtering or cathode sputtering. The sputtering target, which contains the alloy of the active brazing alloy in the desired composition, can be produced by powder metallurgy, for example. However, the powder metallurgical production of such targets is complicated, in particular if the targets contain active components. This then requires crushing and grinding processes under hydrogen atmosphere.

It is therefore the object of the present invention to provide an alternative method which overcomes the disadvantages of the prior art.

The object is achieved by the method according to claim 1.

The method according to the invention for establishing a connection between two surfaces or surface sections of two ceramic parts comprises:
Provide ( 110 ) of a first ceramic part and a second ceramic part;
Provide ( 130 ) an active brazing material on at least a surface portion of at least one of the ceramic parts;
and
Heat the active braze in a brazing process,
wherein the active brazing material for connecting the first and the second ceramic part by a sputtering method ( 130 ) provided,
characterized in that in the implementation of the sputtering method, an intermediate target is coated by sputtering of components of the active brazing with the active brazing, and at least one ceramic part, preferably both ceramic parts is coated in sections by sputtering the coated intermediate targets with the active brazing.

In one development of the invention, the intermediate target is coated in layers with components of the active braze. In one embodiment of this development of the invention, the individual layers of the components of the active brazing on the intermediate target an average thickness of not more than 10 nm, in particular not more than 5 nm, preferably not more than 2 nm and more preferably not more than 1 nm ,

The active brazing solder provided on the ceramic bodies forms by the soldering process a joint whose strength according to a development of the invention does not have more than 20 μm, in particular not more than 15 μm and preferably not more than 10 μm. A corresponding amount of the active brazing material is to be provided on the ceramic bodies, wherein this amount of active brazing material can be deposited on the joining partner in any distribution. From an equal distribution on both joining partners until for the complete separation of the entire active brazing material on one of the joining partners.

In a further embodiment of this development of the invention, the average layer thickness of the layers of the components of the active brazing material on the intermediate target and / or their frequency is a function of the proportion of the component in the alloy. In a further embodiment of this development of the invention, the strength of the individual layers of the components of the active brazing material is controlled on the intermediate target over the respective coating time as a function of a deposition rate of the individual components.

The term "layers" of components of the active braid, in the context of the inventive method, refers to sequentially deposited material of the various components, wherein it is not necessarily implied that a layer completely or homogeneously covers its respective substrate.

This is not to be expected, especially with very thin layers, since metals deposited from the gas phase tend to form islands. The above information on the average layer thicknesses of the components relates in this respect to the one deposited amount of a component which, given a homogeneous distribution, would yield a layer of the given thickness.

In one development of the invention, the components for coating the intermediate target are each sputtered synchronously.

In one development of the invention, the proportion of the components for coating the intermediate target is controlled by means of a potential difference between a noble gas ion source and a respective sputtering target, which has the component.

In one development of the invention, the components for coating the intermediate target are each sputtered by pure sputtering targets, each of which has exclusively the material of the respective component.

In one development of the invention, the intermediate target has a movable body, in particular a rotary body, wherein the movable body or rotary body has a cyclically moving or rotating surface, which is coated with the active brazing material and from which the active brazing material is sputtered. In one embodiment of this development of the invention, in the preparation of layer sequences of individual components of the active hard solder on the intermediate target, the respective times for preparing a layer are multiples, in particular integer multiples of a period of the cyclic movement of the surface of the intermediate target.

In one development of the invention, the intermediate target has a first component of the active brazing material, in particular in its pure form. In one embodiment of this development of the invention, the components of the active brazing are deposited in addition to the first component of the active brazing by sputtering of corresponding targets on the intermediate target.

In a further development of the invention, the sputtering is carried out in a vacuum apparatus having at least a first region and a second region, wherein the surface of the intermediate target moves periodically in sections through the first and second region, wherein each located in the first region surface portion with components the active brazing material is sputtered and sputtered by the active brazing material from a surface portion located in the second region.

In one development of the invention, the active brazing material comprises a Zr-Ni-Ti alloy and, if appropriate, further metals, the first and / or second ceramic part in particular having corundum.

In a development of the invention, the soldering process comprises a vacuum soldering process or a soldering process under protective gas.

In one development of the invention, the first ceramic part comprises a main body of the pressure sensor, wherein the second ceramic part comprises the measuring diaphragm of the pressure sensor, and wherein the measuring diaphragm with the main body along an annular joint, which has the active brazing, pressure-tight. In one embodiment of this development of the invention, the pressure sensor is a differential pressure sensor which has a measuring membrane between two basic bodies or a base body between two measuring membranes to be joined together, wherein the active brazing material for the two joints between the measuring membrane and the counter-bodies or the measuring membranes and the counter body is provided in each case in the same way.

The invention will now be explained with reference to the embodiment shown in the drawing.

It shows:

1 : Components of a ceramic pressure sensor, which are joined by means of the method according to the invention;

2 : A flow chart of an embodiment of the method according to the invention; and

3a A first more detailed flow chart for performing a method step of the embodiment 2 ;

3b A second, more detailed flowchart for carrying out a method step of the exemplary embodiment 2 ;

4a : A detailed flowchart of a first embodiment for coating the intermediate target in layers;

4b : A detailed flowchart of a second embodiment for coating the intermediate target in layers;

5a : A detailed flow chart of an embodiment for sequentially coating an intermediate target having a component of the active braze;

5b : A detailed flowchart of an embodiment for synchronously coating an intermediate target having a component of the active braid;

6a : A detailed flow chart of a first embodiment for synchronously coating the intermediate target with all components of the active braze;

6b : A detailed flowchart of a second embodiment for synchronously coating the intermediate target with all components of the active braze; and

7 : A schematic representation of a vacuum apparatus for carrying out method steps of the method according to the invention.

In the 1 , shown components of a ceramic pressure sensor 1 comprise a circular disk-shaped measuring diaphragm 2 a circular disk-shaped base body 3 , which have corundum. In particular, the measuring membrane can have high-purity corundum with a purity of better than 99.9%, which optionally contains up to about 500 ppm MgO. The measuring membrane 1 and the main body 2 have, depending on the embodiment, for example, a diameter of about 15 to 25 mm. The material thickness of the measuring membrane 2 For example, is 100 microns to 2 mm, while the body has a thickness of several mm. However, the dimensions mentioned are not essential to the invention and can be selected, for example, according to metrological requirements or other boundary conditions. The measuring membrane 1 and the main body 2 are to be pressure-tightly connected by means of a Zr-Ni-Ti active brazing material in a high-vacuum soldering process.

For this purpose, the end faces of the measuring membrane to be joined become 2 and the basic body 3 initially masked in each case to an annular edge region, in order then to prepare the active brazing material for the joint in the annular edge region by means of vapor deposition.

The joint may, for example, have a thickness of 10 .mu.m, for which purpose in each case one layer of the active hard solder having a thickness of 5 .mu.m is to be deposited on the measuring membrane and the base body. After complete separation of the active braze to form the joint, the measuring membrane 2 and the main body 3 superposed with the active brazing coatings and pressure-tightly connected in a vacuum brazing process.

Preferably, electrodes (not shown here) are prepared for a capacitive transducer of the pressure sensor before depositing the active hard solder. This can also be done by means of vapor deposition in a sputtering process. As an electrode material, for example, Ta is suitable, which is deposited in a thickness of, for example, 0.1 to 0.2 microns. A preferred electrode arrangement may, for example, make it possible to form a differential capacitor, for which purpose a central, circular measuring electrode and a capacitor-like annular reference electrode surrounding it are deposited on the end face of the base body in the area to be enclosed by the annular joint. The measuring electrode, the reference electrode and the joint are preferably electrically insulated from each other in the finished pressure sensor. On the membrane, a full-surface counter electrode is preferably prepared, which is preferably in the finished sensor with the joint in galvanic contact.

Exemplary embodiments of the method according to the invention for establishing a connection between ceramic bodies, for example the above components of a pressure sensor, will now be explained with reference to the remaining figures. This shows 2 first generally a known per se method 100 with a sequence of steps providing 110 of ceramic bodies, masking 120 non-coated areas, coating 130 / 230 the ceramic body with active brazing, positioning 140 the ceramic body to each other, and joining 150 the ceramic body comprises in a vacuum brazing process.

The peculiarity of the present invention relates to the coating 130 which in two Alternatives in 3a and 3b is shown. Accordingly, the coating takes place 130 in the way that an intermediate target by sputtering 131 / 231 of targets, which contain the components of the active brazing in particular in pure form, is coated with the active solder, and that the ceramic body by sputtering 131 / 231 of the active braze from the intermediate target.

At the in 3a 1, a fraction of the required total quantity of the active brazing material is first sputtered onto the intermediate tarpaulin 131 wherein the active brazing material thus deposited on the intermediate target is immediately sputtered off the intermediate target 132 to coat the ceramic body. Until the required target thickness of the active brazing material on the ceramic bodies is reached, the alternating process of coating the intermediate target by sputtering is achieved 131 and sputtering down 132 the Aktivhartlots of the intermediate target on the ceramic body repeatedly to go through. For this purpose, it is possible, for example, to use a rotating, cylindrical intermediate target, on the passing circumferential surface of which components of the active brazing material are deposited in a first stationary position and sputtered down in a second, second stationary position from the passing lateral surface. Thus, the coating of the intermediate target and the sputtering from the intermediate target may occur simultaneously.

At the in 3b illustrated second alternative, a supply of the active braze is first sputtered onto the intermediate target 231 wherein the supply is at least sufficient to coat the ceramic body in the required nominal thickness. Subsequently, the active brazing material deposited by sputtering on the intermediate body is sputtered down from the intermediate target 232 to coat the ceramic body until it reaches the required nominal thickness of the active braid on the ceramic bodies. In fact, the stock deposited on the intermediate target can be sufficiently large that it can coat several batches of ceramic bodies in the desired thickness.

In this second alternative, since the operations of depositing the active braze on the intermediate target and sputtering the active brazing agent on the intermediate target are completely independent of each other, the freedom of the intermediate target is increased. In principle, any desired vacuum-compatible substrate body on which the active brazing material can be deposited can serve as an intermediate target. Nevertheless, a rotating, cylindrical intermediate target can also be advantageous for the second alternative of the method. For in a coating of the passing lateral surface by sputtering of components of the active brazing from stationary targets containing the components in pure form, possibly occurring inhomogeneities of the spatial distribution of the material flow from the targets affect less.

4a and 4b show flowcharts in which the intermediate target is coated sequentially with the components of the active braid.

At the in 4a 1, a fraction of the required total quantity of the active brazing material is first sputtered sequentially onto the intermediate target, wherein in a first step 1311 first a first component, then in a second step 1312 a second component, and then in a third step 1313 a third component of the active braid is deposited on the intermediate target, wherein in one step 132 the active brazing material is immediately sputtered down from the intermediate target to coat the ceramic bodies. Until the required target thickness of the active brazing material on the ceramic bodies is reached, the alternating process of sequentially coating the intermediate target by sputtering is achieved 131 and sputtering down 132 the Aktivhartlots of the intermediate target on the ceramic body repeatedly to go through.

The individual layers should not be too strong to allow a sufficiently homogeneous deposition of the active braze on the ceramic bodies during melting of the active brazing during soldering. Thus, the layer thicknesses should preferably be not more than 10 nm, in particular not more than 5 nm.

In principle, the layer thickness ratios of the layers of the components deposited in each case in one step can correspond to the proportions in the target composition of the active brazing alloy.

However, there are alloys that can not be reasonably represented by a variation of the layer thickness with the same frequency of the layers of the individual components. Thus, for the components c _Zr , c _Ni , c _{Ti of} a preferred Zr-Ni-Ti alloy (in atomic%): 61 <c _Zr <63.5; 21.5 <c _Ni <24 and 14.5 <c _Ti <15.5.

Taking into account the respective atomic masses and solid-state densities of the pure materials, this results in a composition (in atomic%) with c _Zr = 62; c _Ni = 23 and c _Ti = 15 the following layer thickness ratios: d _Zr = 5 nm; d _Ni = 0.8 nm and d _Ti = 0.9 nm

In order to increase the thickness of the titanium layer, the frequency of the zirconium layer can be doubled. The layer sequence is then ... Zr, Ni, Zr, Ti, Zr, Ni, Zr, Ti ... with the following layer thickness ratios: d _Zr = 5 nm; d _Ni = 1.6 nm and d _Ti = 1.8 nm

This approach is in 4a as an option, in which the first component is deposited twice as often as the second or third component, where Zr corresponds to the first component, while Ni and Ti form the second or third component. Although this approach in the present application only in 4a is shown graphically, it can be used in all embodiments of the invention, in which layer sequences of the components are deposited on the intermediate target.

The thickness of the individual layers is controlled during sputtering via the component-specific electrical power and the sputtering time, wherein the atomic mass and the density of the component are included in the deposition rate for a given power.

As an intermediate target, for example, a rotating cylinder can be used, on the passing circumferential surface of which first stationary positions components of the active brazing material are sequentially deposited and sputtered down in a second stationary position from the passing lateral surface. In order to achieve a sufficient uniform distribution of the respective component on the lateral surface of the cylinder, the duration of the deposition of a component should preferably be an integral multiple of the time one revolution of the intermediate target. This recommendation applies to all embodiments in which layer sequences of components of the active braid are deposited on an intermediate target.

At the in 4b illustrated embodiment of the method is initially a sequential coating 231 of the intermediate target, with a supply of Aktivhartlots that is at least sufficient to coat the ceramic body in the required nominal thickness. Subsequently, the active brazing material deposited by sputtering on the intermediate body is sputtered down from the intermediate target 232 to coat the ceramic bodies until the required strength of the active brazing alloy has been achieved.

For sequentially coating the intermediate target, in a first step in 2311 first a first component, then in a second step 2312 a second component, and then in a third step 2314 a third component of the active braid deposited on the intermediate target. The step sequence 2311 . 2312 . 2313 is repeated until a sufficient supply of the active braze for coating the ceramic body is present on the intermediate target.

Although, as related to 3b discussed, the intermediate target can be arbitrarily shaped, a rotating, cylindrical intermediate target is also advantageous for this embodiment of the method. For in a coating of the passing lateral surface by sputtering of components of the active brazing from stationary targets containing the components in pure form, possibly occurring inhomogeneities of the spatial distribution of the material flow from the targets affect less.

5a and 5b show flowcharts in which the intermediate target has a solid surface of a first component of the active braid, on which then only the remaining components are to be sputtered. In these embodiments of the invention, it is believed that the first component is the one with the largest amount of alloy. This eliminates a significant proportion of the sputtering time when coating the intermediate target. Naturally, in this procedure, the first component is covered with increasing amount of the other components. Thus, it is necessary to sputter down in time the material of the other components accumulated on the intermediate target together with material of the first component from the surface of the intermediate target, in order to achieve a sufficient mixing of the components on the ceramic bodies. The accumulation of a supply of active brazing material for complete coating of the ceramic body in the required thickness of, for example, 10 microns thus eliminates the variants of the invention, in which a component of the active braze is present exclusively as a solid material of the surface of the intermediate target. The term "solid material" in this context refers to such an amount of material that is sufficient for a large number of passes of the method for coating the ceramic body with active brazing, for example, at least 100 passes, preferably at least 1000 passes.

At the in 5a illustrated embodiment is accordingly to an intermediate target, which has a solid surface of the first component of the active braze, in a first step 1311' first a second component and in a second step 1312' deposited a third component each in a thickness of a few nm, immediately thereafter in one step 132 the Aktivhartlotmaterial, which on the one hand, the previously deposited second and third Component and on the other hand the first component of the solid surface of the intermediate target is sputtered off the intermediate target to coat the ceramic bodies. Until the required target thickness of the active brazing material on the ceramic bodies is reached, the alternating process of sequentially coating the intermediate target with the second and third components by sputtering is achieved 131' and sputtering down 132 the Aktivhartlots of the intermediate target on the ceramic body repeatedly to go through.

At the in 5b illustrated embodiment are in an intermediate step, which has a solid surface of the first component of the active brazing, in a first step 1311'' the second component and the third component of the active braid are deposited by synchronous sputtering in a thickness of a few nm, immediately thereafter in one step 132 the active brazing material, which on the one hand comprises the previously deposited second and third components and on the other hand the first component of the solid surface of the intermediate target, is sputtered down from the intermediate target to coat the ceramic bodies. Until the required target thickness of the active brazing material on the ceramic bodies is reached, the alternating process of coating the intermediate target with the second and third components by synchronous sputtering is achieved 1311'' and sputtering down 132 the Aktivhartlots of the intermediate target on the ceramic body repeatedly to go through.

Synchronous sputtering can be performed in particular as DC sputtering, wherein the sputtering rates of the components can be controlled by the potential difference between that of a sputtering ion source and the respective target having the component in its pure form.

6a and 6b show flowcharts in which the intermediate target is coated by synchronous sputtering with all components of the active braid.

At the in 6a 1, a fraction of the required total quantity of the active brazing material is first sputtered sequentially onto the intermediate target 131''' , Wherein all the components of the active brazing, in a ternary active hard solder so the first, second and third components, in one step 1311''' is deposited by synchronous sputtering on the intermediate target, wherein in one step 132 the active brazing material is immediately sputtered down from the intermediate target to coat the ceramic bodies. Until the required target thickness of the active hard solder on the ceramic bodies is reached, the alternating process of coating the intermediate target by synchronous sputtering is achieved 131 and sputtering down 132 the Aktivhartlots of the intermediate target on the ceramic body repeatedly to go through.

Insofar as the components on the intermediate target are sufficiently mixed in synchronous sputtering of all components of the active hard solder, it is not necessary to limit the strength of the active hard solder on the intermediate target. However, sputtering off the intermediate target immediately after deposition on the intermediate target has the effect of reducing the overall time for coating the ceramic bodies with the active brazing solder. If, for example, the intermediate target comprises a rotating cylinder, components of the active brazing material are deposited synchronously on its passing lateral surface in a first stationary position and are sputtered down from the passing lateral surface in a second second stationary position, then coating the intermediate target and sputtering off Intermediate target even done simultaneously.

The sputtering of fractions of the total amount of active brazing alloy required to coat the ceramic bodies from the intermediate target, immediately after deposition on the intermediate target, as shown in FIG 3a . 4a . 5a . 5b and 6a In addition, stratification of the active brazing material deposited on the ceramic bodies can be easily controlled. Thus, for example, first a thin layer of, for example, 100 nm with an average composition of the active brazing material having a low melting point can be deposited directly on the surface of the ceramic body, while subsequently thicker layers of a composition can be deposited whose thermal expansion coefficient is matched to the material of the ceramic body , but possibly has a higher melting point.

At the in 6b illustrated embodiment of the method is initially a synchronous coating 231' of the intermediate target, with a supply of Aktivhartlots that is at least sufficient to coat the ceramic body in the required nominal thickness. Subsequently, the active brazing material deposited by sputtering on the intermediate body is sputtered down from the intermediate target 232 to coat the ceramic bodies until the required strength of the active brazing alloy has been achieved. For synchronous coating of the intermediate target are in one step 2311' deposited all components of the active braze by synchronous sputtering on the intermediate target until a sufficient supply of active brazing for coating the ceramic body is present on the intermediate target.

The application of an intermediate supply of the active brazing material with a desired target composition can be carried out independently of the coating of the ceramic bodies and is in particular comparatively easy to control in synchronous sputtering of all components to the intermediate target.

In the 6 schematically illustrated apparatus 300 for performing the sputtering steps of the method according to the invention comprises a vacuum chamber 310 with a first compartment 312 and a second sub-chamber 314 between which a shroud 316 is arranged. The first sub-chamber contains a first ion source 320 and the second subchamber a second ion source 322 for ionizing an introduced noble gas, in particular argon.

In the first compartment 312 are primary targets 330 . 331 . 332 which contain components of an active brazing alloy in pure form, for example, Zr, Ni and Ti. The targets are via electrical feedthroughs to a high voltage source 340 connected, with which potentials of the primary targets 330 . 331 . 332 can be adjusted independently of each other. The potentials are actually negative potentials that are chosen to be that of the first ion source 320 To the primary targets, Ar ions accelerated sputter out the respective components of the active braze from the primary targets at the rate desired for the target composition.

The apparatus also contains a rotating cylinder as an intermediate target 350 , on the lateral surface of which are sputtered from the primary targets sputtered components. The axis of the cylinder 350 runs parallel to a plane in which the aperture 316 extends. The aperture 316 has an opening which is penetrated by the cylinder. The axis of the cylinder 350 can lie in particular in this plane, so that in each case one half of the lateral surface of the cylinder 350 or of the intermediate target is located in one of the two sub-chambers.

By the rotation of the cylinder 350 the coated sections of the jacket surface come out of the first compartment 312 into the second compartment 314 where the active brazing material or its components are sputtered from the lateral surface.

To make this possible, the outer surface of the cylinder is 350 conductive and is via a sliding contact 352 from the high voltage source 340 brought to a negative potential, which is less negative than the potentials of the primary targets. The second ion source 322 emitted Ar ions are accelerated to the lateral surface and sputtering there the active brazing alloy or its components, which then on the ceramic bodies 360 be deposited.

On the ion sources 320 . 322 can also be dispensed with, in which case between the primary targets and the intermediate target or between the substrates to be coated in each case a voltage is applied, which causes the ignition of a plasma, which provides the ions for sputtering.

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

• EP 0490807 B1 [0003]
• EP 0558874 B1 [0003]
• EP 0988919 A1 [0003]
• DE 102010043119 A1 [0006]

Claims (17)

A method of forming a bond between two surfaces or surface portions of two ceramic parts, comprising: providing ( 110 ) of a first ceramic part and a second ceramic part; Provide ( 130 ) an active brazing material on at least a surface portion of at least one of the ceramic parts; and heating the active hard solder in a soldering process, wherein the active brazing material for bonding the first and second ceramic parts by a sputtering method (US Pat. 130 ), characterized in that in carrying out the sputtering method an intermediate target is coated by sputtering components of the active brazing material with the active brazing material ( 131 ), and at least one ceramic part, preferably both ceramic parts, is coated in sections by sputtering the coated intermediate target with the active brazing material or 132 ). The method of claim 1, wherein the intermediate target is coated in layers with components of the active braze. The method of claim 2, wherein the individual layers of the components of the active braid on the intermediate target have an average thickness of not more than 10 nm, in particular not more than 5 nm, preferably not more than 2 nm and particularly preferably not more than 1 nm. Method according to one of claims 2 to 3, wherein the average layer thickness of the layers of the components of the active braid on the intermediate target and / or their frequency is a function of the proportion of the component to the alloy. Method according to one of claims 2 to 4, wherein the thickness of each of the layers of the components of the active braid is controlled on the intermediate target over the respective coating time in dependence on a deposition rate of the individual components. The method of claim 1, wherein the components for coating the intermediate target are respectively sputtered synchronously. Method according to one of the preceding claims, wherein the proportion of the components for coating the intermediate target is controlled by a potential difference between a noble gas ion source and a respective sputtering target comprising the component. Method according to one of the preceding claims, wherein the components for coating the intermediate target are each sputtered by pure sputtering targets, each of which exclusively comprises the material of the respective component. Method according to one of the preceding claims, wherein the intermediate target comprises a movable body, in particular a rotary body, wherein the movable body or rotating body has a cyclically moving or rotating surface which is coated with the active brazing material and from which the active brazing material is sputtered. The method of claim 9, wherein in the preparation of layer sequences of individual components of the active braid on the intermediate target, the respective times for preparing a layer multiples, in particular integer multiples of a period of the cyclic movement of the surface of the intermediate target. Method according to one of the preceding claims, wherein the intermediate target comprises a first component of the active brazing, in particular in pure form. The method of claim 11, wherein the components of the active braze are deposited on the intermediate target by sputtering corresponding targets in addition to the first component of the active braze. The method of claim 9 or claim 9, wherein the sputtering is carried out in a vacuum apparatus having at least a first region and a second region, wherein the surface of the intermediate target moves periodically through the first and second regions in a periodic manner each surface portion located in the first region is coated with components of the active braze and wherein the active brazing material is sputtered by a surface portion located in the second region. Method according to one of the preceding claims, wherein the active brazing material comprises a Zr-Ni-Ti alloy and optionally other metals, wherein the first and / or second ceramic part in particular corundum. Method according to one of the preceding claims, wherein the soldering process comprises a vacuum brazing process or a brazing process under protective gas. Method according to one of the preceding claims, wherein the first ceramic part a Base body of the pressure sensor comprises, wherein the second ceramic part comprises the measuring diaphragm of the pressure sensor, and wherein the measuring diaphragm with the main body along an annular joint, which has the active brazing material, are pressure-tight manner The method of claim 16, wherein the pressure sensor is a differential pressure sensor having a measuring membrane between two basic bodies or a base body between two measuring membranes to be joined together, wherein the Aktivhartlotmaterial for the two joints between the measuring membrane and the counter-bodies or the measuring membranes and The counter-body is provided in the same way.

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