Metallization and carrier having metallization

Abstract

The invention relates to a system (36) having a carrier (3) and at least one metallization (6); wherein the metallization (6) has at least a first layer (1) and a second layer (2); wherein the carrier (3) has a carrier surface (7); wherein the first layer (1) is arranged between a carrier surface and the second layer (2); wherein the second layer (2) is made of at least 90% by weight of a noble metal; wherein the first layer (1) is made of transition metal and / or metal and / or semimetal; wherein the first layer (1) is ultrasonically damped.

Description

Technical Field

[0001] The present invention relates to a metallization having a first layer and a second layer, and a carrier having the metallization, such as an oxide ceramic, the metallization having improved stability. Background Art

[0002] Oxide ceramics are used as carriers (also referred to as substrates) in a variety of applications, such as as insulators, substrates in circuit boards, or as measuring elements.

[0003] In technical applications, carriers are usually provided with a metallization. This is usually provided for conducting electric charges. Thus, the metallization can be provided as a conductor circuit, an electrode, or as protection against static electricity for otherwise electrically insulating surfaces. In this case, the metallization covers at least one sub-region of the oxide ceramic surface.

[0004] For the metallization of oxide ceramics such as quartz, gallium phosphate, or lanthanum gallium silicate, layer structures composed of refractory metals and noble metals are usually used. The refractory metal layer serves as an adhesion layer because it enables good adhesion to the oxide ceramic due to its high oxygen affinity. In contrast, the noble metal layer is used for good electrical conductivity and / or bondability of the layer.

[0005] Refractory metals are understood to be elements of the fourth subgroup (titanium, zirconium, and hafnium), the fifth subgroup (vanadium, niobium, and tantalum), or the sixth subgroup (chromium, molybdenum, and tungsten). In the sense of this application, noble metals are understood to be gold, platinum, iridium, palladium, osmium, ruthenium, rhodium, and silver.

[0006] Bondability exists when a conductor, such as a bonding lead made of gold or aluminum, can effect a material-fit connection (also referred to as contact) between the layer and the conductor by means of common bonding techniques, such as wire bonding (also known under the concepts of ultrasonic bonding or thermosonic bonding).

[0007] It is known that materials with a high elastic modulus, such as refractory metals, have only small damping characteristics for mechanical vibrations. This is disadvantageous because the ultrasound used in wire bonding is well transmitted to the carrier. The resulting mechanical loads due to the mechanical vibrations of the ultrasound often lead to spalling and / or cracking in the carrier, especially in the oxide ceramic carrier, which in turn reduces the adhesion strength of the material-fit connection (also referred to here as bonding). Cracks and / or spalling are usually referred to as damage caused by mechanical stress (also referred to as mechanical load) due to vibration.

[0008] Ultrasound is generally understood to be sound or sound waves with a frequency between 20 kHz and 1 GHz. Sound waves are mechanical vibrations.

[0009] In particular, in an oxide ceramic serving as a carrier, spalling and / or cracking in the carrier near or at the contact portion is unacceptable. The oxide ceramic has piezoelectric properties and is used as a measuring element in a sensor subjected to mechanical stress. Mechanical loads, such as the acceleration of the sensor, may cause damage in the contact portion.

[0010] Piezoelectric measuring elements known from patent documents EP2013597A1 and EP2029988A2 often have metallizations in the form of conductive layers. In order to mechanically protect the often brittle piezoelectric material, which is often also implemented as a single crystal, platinum is partly used as the conductive layer. As a noble metal, platinum also has good chemical stability against oxidation. The disadvantage here is that when contacting the metallization by wire bonding, the piezoelectric crystal under the metallization may be damaged due to the mechanical vibrations of the transmitted ultrasound. This is not directly visible through the metallization at first, since the metallization is usually not damaged, but it results in insufficient durability or adhesion strength of the contact between the metallization and the conductor, because the connection between the metallization and the piezoelectric measuring element is damaged.

[0011] The object of the present invention is to provide a metallization for a carrier that avoids the above-mentioned disadvantages. Another object of the present invention is to reduce the mechanical load on the carrier during wire bonding by vibrations, such as ultrasound. Another object of the present invention is to provide a system composed of a metallization and a carrier that can be well contacted by wire bonding. Summary of the Invention

[0012] This object is achieved by the features of the present invention.

[0013] The present invention relates to a system having a carrier and at least one metallization. The metallization has at least a first layer and a second layer. The carrier has a carrier surface. The first layer is arranged between the carrier surface and the second layer.

[0014] A layer, also referred to as a coating, is applied to the carrier, which is also referred to as a substrate or base material. It at least partly covers the surface of the carrier, briefly referred to as the carrier surface. Thus, the layer has an extension along a first axis and a second axis, wherein the first axis and the second axis are arranged parallel to the carrier surface. The layer also has an extension along a third axis perpendicular to the carrier surface, and this extension is referred to as the layer thickness. The layer is implemented such that it also evenly covers the topography of the carrier surface if necessary. The layer thickness is determined by X-ray fluorescence spectrometry according to ISO 3497:2000 of the International Organization for Standardization.

[0015] The second layer is made of at least 90% by weight (90 weight percent) of a noble metal. This has the advantage that the layer is corrosion-resistant and thus has high chemical stability. Noble metals are elements with a strong positive standard electrode potential (also called standard electrode potential relative to the hydrogen electrode). Thus, for example, gold has a standard electrode potential of 1.5 V (volts), and silver has a standard electrode potential of 0.8 V. In addition, the second layer has high electrical conductivity due to the high share of noble metal and is thus suitable as an electrode for conducting electric charges and for contacting via a conductor.

[0016] The first layer is made of a transition metal and / or a metal and / or a metalloid. The expression "and / or" is understood as a non-exclusive disjunction. The first layer is ultrasonic damping. This has the advantage that the mechanical load on the carrier caused by vibrations, such as ultrasound, is reduced. Thus, advantageously, the mechanical load on the carrier caused by mechanical vibrations, which occur, for example, during wire bonding, is reduced. Especially in the case of an oxide ceramic carrier, the adhesion strength of the material-fit connection between the conductor and the second layer is increased after wire bonding.

[0017] In wire bonding, the first end of the conductor (also called bonding wire) is pressed onto the second layer using a bonding tool. The bonding tool transfers ultrasonic vibrations to the conductor. This causes a diffusion process between the conductor and the second layer, thereby creating a material-fit connection. However, the ultrasound is not localized to the first layer but propagates through the first layer and the second layer to the carrier. Through the ultrasonic-damping second layer, the mechanical load on the carrier caused by the mechanical vibrations of the ultrasound is reduced.

[0018] Other advantages and aspects of the present invention are disclosed in the embodiments. Description of the Drawings

[0019] The present invention will be described in detail below with reference to the accompanying drawings by way of example. Among them

[0020] Figure 1 A schematic cross-sectional view of an embodiment of the system is shown;

[0021] Figure 2 A schematic cross-sectional view of an embodiment of the contact system is shown;

[0022] Figure 3 A schematic cross-sectional view of another embodiment of the contact system is shown;

[0023] Figure 4 A schematic partial view of another embodiment of the contact system is shown;

[0024] Figure 5 A schematic partial view of another embodiment of the contact system is shown;

[0025] Figure 6Shows a schematic partial view of another embodiment of the contact system.

[0026] The same reference numerals in the drawings denote the same objects or features.

[0027] Among them, the list of reference numerals is as follows:

[0028] 1 First layer

[0029] 2 Second layer

[0030] 3 Carrier

[0031] 4 Conductor, bonding lead

[0032] 5 Connection part, bonding, material mating connection, ball bonding, wedge bonding

[0033] 6 Metallization part

[0034] 7 Carrier surface

[0035] 8 First conductor end

[0036] 9 Second conductor end

[0037] 12 Contact plane

[0038] 13 Contact plane

[0039] 36 System

[0040] 364 Contact system

[0041] X First axis

[0042] Y Second axis

[0043] Z Third axis Detailed implementation

[0044] Figure 1 Shows a schematic cross-sectional view of an embodiment of the system 36. Figure 1 The system 36 in has a carrier 3 and a metallization part 6. The metallization part 6 has a first layer 1 and a second layer 2. The carrier 3 has a carrier surface 7, and the carrier surface extends along the first axis X in the exemplary Figure 1 and extends into the drawing plane. Therefore, the system 36 is schematically shown in a cross-section perpendicular to the carrier surface 7. The first layer 1 is arranged between the carrier surface 7 and the second layer 2.

[0045] In Figures 1 to 6 The dimensions shown are neither shown to scale, nor can the dimensions of individual elements be known from the dimensional ratios between each other. It involves a pure schematic diagram.

[0046] According to the present invention, in all exemplary embodiments shown in the drawings and all other embodiments not shown, the second layer 2 is made of at least 90% by weight of a noble metal. This has the advantage that the second layer 2 is corrosion-resistant and thus has high chemical stability. In addition, the second layer 2 has high electrical conductivity due to the high proportion of noble metal and is thus suitable as an electrode for charge conduction and for contacting via the conductor 4, as exemplarily shown in Figures 2 to 6 as shown.

[0047] According to the present invention, the first layer 1 is made of a transition metal and / or a metal and / or a semi-metal in all embodiments. Also according to the present invention, the first layer 1 is ultrasonic damping. Ultrasonic damping is understood as reducing the intensity of sound waves passing through the ultrasonic damping layer. This has the advantage that the mechanical load on the carrier 3 due to vibrations, such as ultrasound, is reduced. Thus, the mechanical load on the carrier 3 due to mechanical vibrations is advantageously reduced, which mechanical vibrations occur, for example, during wire bonding. Particularly in the case of an oxide ceramic carrier 3, the adhesion strength of the material fit connection between the conductor 9 and the second layer 2 is increased after wire bonding.

[0048] Preferably, the first layer 1 has a mechanical loss coefficient (English: loss coefficient) of at least 10 -4 . This has the advantage that the system 36 can be contacted by wire bonding while the mechanical load on the carrier is minimized, thereby reducing the risk of damage to the carrier due to mechanical vibrations. In this case, the loss coefficient is understood as the coefficient according to "《On the Engineering Properties of Materials》, M.F. Ashby, Acta metall. Vol. 37, No. 5, pp. 1273 - 1293, (1989)", which is referred to therein as "loss coefficient or damping coefficient η (lowercase Greek letter η)". In Ashby's publication, the loss coefficient is equal to the tangent of the loss angle and equal to the ratio of the loss modulus to the storage modulus and is thus dimensionless. According to a first approximation, the loss coefficient is inversely proportional to the Young's Modulus of a material such as an alloy or a metal.

[0049] The Young's Modulus of a material always refers to the macroscopic body of the material, which is also referred to as a massive sample (Massivprobe) in the professional literature and is determined according to DIN EN ISO 6892 - 1 and / or DIN EN ISO 6892 - 2.

[0050] The determination of the loss factor is described in "《A Comprehensive Report on Ultrasonic Attenuation of Engineering Materials,Including Metals,Ceramics,Polymers,Fiber-Reinforced Composites,Wood,and Rocks》,Kanji Ono,Appl.Sci.,10,2230(2020)".

[0051] Particularly preferably, the first layer 1 has a loss factor of at least 10 -4 and in addition has a layer thickness between about 500 nm (nanometers) and about 4 μm (micrometers). It has been confirmed that with a layer having a smaller layer thickness, an appropriate mechanical damping of the mechanical vibrations introduced into the second layer 2 by the first layer 1 cannot be achieved, thereby avoiding damage to the carrier. On the other hand, an excessive layer thickness of the first layer exceeding 4 μm results in a reduction in adhesion promotion due to the internal stress in the layer. This may lead to peeling of the layer.

[0052] In one embodiment, the first layer 1 in addition has a loss factor of at least 10 for mechanical vibrations with a frequency between 20 kHz and 200 kHz, preferably between 40 kHz and 160 kHz. -4 This is advantageous since wire bonding is generally carried out in a frequency range between 20 kHz and 200 kHz, and most commercial devices for wire bonding currently operate at frequencies between 40 kHz and 160 kHz.

[0053] In one embodiment, the first layer 1 in addition has a modulus of elasticity between 60 GPa and 130 GPa; preferably has a modulus of elasticity between 80 GPa and 100 GPa. This is advantageous because the stress generated by ultrasound expands the layer less. This is known from Hooke's law since the elongation is equal to the stress divided by the modulus of elasticity. Thus, the risk of damaging the first layer 1 itself due to mechanical loading, such as when ultrasonic vibrations act on the first layer, is reduced.

[0054] Preferably, the first layer 1 is composed of a metal or an alloy which has a negative standard enthalpy of formation for the oxide of the relevant metal or alloy in a temperature range up to 350 °C. This has the advantage that the first layer 1 has an improved adhesion ability at the carrier 3 compared to a layer composed of an alloy having a neutral or positive standard enthalpy of formation for the oxide.

[0055] A negative standard enthalpy of formation represents a negative Gibbs oxidation energy in an Ellingham diagram.

[0056] The standard enthalpy of formation is determined on the macroscopic solid of the layer material, which is also referred to as the macroscopic sample. The standard enthalpy of formation is determined according to DIN 51007-1 by calorimetry and Hess' law (Satz von Hess), also known as Hess' law of constant heat summation (English: Hess’ law of constant heat summation, also known as Hess' law).

[0057] Preferably, the first layer 1 is made of bronze. Bronze, also known as bronze alloy, is a copper alloy.

[0058] If the carrier 3 is an oxide ceramic, the metallization 6 is particularly suitable for the system 36 in its various embodiments. Therefore, the carrier 3 has a modulus of elasticity between 60 GPa and 120 GPa and has a thermal longitudinal expansion coefficient between α = 5·10 -6 K -1 and α = 20·10 -6 K -1 The thermal longitudinal expansion coefficient relates to the thermal longitudinal expansion coefficient of the layer material or the oxide ceramic as the macroscopic solid (also referred to as the macroscopic sample). The thermal longitudinal expansion coefficient is determined according to DIN 51045-1 with a dilatometer.

[0059] The thermal longitudinal expansion coefficient, abbreviated as the longitudinal expansion coefficient, is also synonymously referred to as the coefficient of thermal expansion.

[0060] Specific oxide ceramics that are particularly prone to damage due to mechanical loading have a modulus of elasticity between 90 GPa and 110 GPa and a thermal longitudinal expansion coefficient between α = 12·10

[0061] K -6 and α = 18·10 -1 K -6 and α = 18·10 -1 between.

[0062] Preferably, the first layer 1 is implemented as an attachment for the carrier surface 7 and is connected in a material - matching manner to the carrier surface 7. Therefore, the first layer 1 is implemented both as an ultrasonic damper and as an attachment between the second layer 2 and the carrier 3. This is advantageous because it provides good contactability of the system with the conductor 9 and the stability of this contact between the conductor 9 and the second layer 2. Not only is damage to the carrier 3 avoided, but good adhesion of the second layer 2 to the carrier 3 is also promoted.

[0063] Preferably, the first layer 1 has a thermal longitudinal expansion coefficient between α = 5·10 -6 ·K -1 and α = 18·10 -6 ·K -1The coefficient of thermal expansion between them. This is advantageous because thermal-induced mechanical stress between the first layer 1 and the carrier 3 is thus avoided. When the difference in the coefficients of thermal expansion of the two materials is large, thermal-induced mechanical stress occurs when the temperature changes between the two materials.

[0064] Preferably, the second layer 2 has a layer thickness between 20 nm and 300 nm. The second layer 2 is suitable for contacting the conductor 9 by wire bonding and already has good electrical conductivity in the case of a small layer thickness of 20 nm. A layer thickness greater than 300 nm should be avoided for cost reasons on the one hand. In addition, as the layer thickness of the second layer increases, the mechanical stress between the first layer 1 and the second layer 2 may increase in the case of different coefficients of thermal expansion. In the case of a layer thickness greater than 300 nm, the second layer 2 has unfavorable intrinsic stress.

[0065] Particularly advantageously, the second layer 2 has high chemical stability. Thus, the first layer 1 is advantageously protected from environmental influences, such as oxidation by oxygen. Here, in particular, gold or platinum or a gold alloy or a platinum alloy is suitable as the material of the second layer 2.

[0066] Particularly advantageously, the second layer 2 has high mechanical stability. Thus, the first layer 1 is advantageously protected from environmental influences, such as mechanical loads that cause scratches. For this purpose, the second layer 2 has an elastic modulus greater than 150 GPa. Here, in particular, platinum or a platinum alloy is suitable as the material of the second layer 2. Platinum and platinum alloys have high scratch resistance. High scratch resistance is obtained when the Mohs hardness > 3. Preferably, the second layer 2 has a Mohs hardness > 3. Gold has a Mohs hardness of about 2.5 and is therefore not considered scratch-resistant. Platinum has a Mohs hardness of 3.4 and is therefore scratch-resistant, like platinum alloys with a Mohs hardness > 3.

[0067] Particularly preferably, the first layer 1 is a bronze alloy having copper, tin, and nickel; wherein, the first layer 1 preferably has 84.5% to 87.5% by weight of copper, 11% to 13% by weight of tin, and 1.5% to 2.5% by weight of nickel. Particularly preferably, the first layer 1 has a maximum of 16% by weight of elements other than copper, tin, and nickel. It has been confirmed that this bronze alloy has a particularly advantageous E modulus (elastic modulus) of about 90 GPa and a particularly advantageous coefficient of thermal expansion of 17.5·10 -6 K -1 Therefore, the second layer 2 is particularly suitable as an attachment for ultrasonic damping for specific oxide ceramics, which have an elastic modulus between 90 GPa and 110 GPa and an α = 12·10 6 K -1 and an α = 18·10 -6 K -1Thermal longitudinal expansion coefficients therebetween. For the preferred good contactability of the system by wire bonding, the deviation of the elastic modulus of the first layer 1 from the elastic modulus of the carrier 3 is not more than 20%, preferably not more than 10%. It has been confirmed that for the system 36 to have particularly good stability with respect to damage to the carrier 3, the deviation of the thermal expansion coefficient of the first layer 1 from the thermal expansion coefficient of the carrier 3 is not more than 20%, preferably not more than 10%.

[0068] The metallization 6 is particularly suitable for a carrier 3 made of a piezoelectric material, preferably a piezoelectric crystal. Piezoelectric materials are usually used in combination with mechanical loads, for example as actuators (where voltage is supplied to the surface of the carrier) or as piezoelectric measuring elements (where mechanical force is applied to the surface 7 of the carrier). The metallization 6 described here is particularly robust with respect to external mechanical influences due to its mechanical stability.

[0069] The carrier 3 with the metallization 6 is often in contact with conductors, as exemplarily shown in Figure 2 and Figure 3 A carrier 3 that is contacted in this way is called a contact system 364. The contact system 364 has a carrier 3, at least one metallization 6 and at least one conductor 4. The conductor 4 has a first conductor end 8 and a second conductor end 9. The first conductor end 8 is connected in a material - fitting manner to the second layer 2. The second layer 2 has good bondability with the conductor 4. The conductor 4 is, for example, a bonding wire, preferably a bonding wire made of gold or a bonding wire made of aluminum.

[0070] In the contact system 364, the conductor 4 is preferably connected to the second layer 2 by means of a ball bond 5 (as shown in Figure 2 or a wedge bond 5 (as shown in Figure 3 in a material - fitting manner.

[0071] Figures 4 to 6 Some embodiments of the contact system 364 are exemplarily shown. However, the implementation is not limited to the shown embodiments. Thus, in particular, other partial coverings of the carrier surface 7 or other geometric embodiments of the carrier are also conceivable. Similarly, only one or two contact portions by the conductor 4 are exemplarily shown. However, it is explicitly stated that multiple contacts by multiple conductors 4 are also possible.

[0072] Figure 4 A square carrier 3 is shown. One of the multiple surfaces is partially covered as the carrier surface 7 by a strip - shaped metallization 6, which is shown as a dotted - surface. The metallization 6 and the conductor 4 are at the first conductor end 8 (not shown for clarity in Figures 4 to 6 and in Figure 2 and Figure 3is connected in a material - fitting manner by means of a connecting portion 5 on (as shown in). Here, the conductor is shown with an arbitrary length as in Figures 2 to 6 , which is shown by a bent breaking edge. The second conductor end is not shown. A person skilled in the art can design the metallization also as a conductor circuit on the carrier 3 similar to the Figure 4 embodiment.

[0073] In Figure 5 , an embodiment is shown in which the upper surface and the lower surface of the square carrier 3 are each covered with a metallization 6 over their entire extent. Each metallization 6 is connected in a material - fitting manner to the conductor 4 at the first conductor end 8 by means of a connecting portion 5. This embodiment can be used, for example, as a piezoelectric measuring element having a piezoelectric transverse effect, wherein the piezoelectric charge during lateral force loading of the square carrier 3 can be led out by means of the metallization 6. In the case where the carrier is implemented as a piezoelectric measuring element, the corresponding second end 9 of the conductor (not shown) is usually conductively connected to a charge amplifier or an impedance converter (both not shown). A person skilled in the art can also implement the edge regions of the upper and lower surfaces without metallization to avoid lateral contact (not shown).

[0074] Figure 6 is an embodiment in which the upper surface and the lower surface of the disk - shaped carrier 3 are each covered with a metallization 6 over their entire extent. The side surface has two sub - regions with metallizations 6, one of each of which is conductively connected to the metallization of the upper surface or the lower surface and thus forms, in this embodiment, the metallizations 6, i.e., a total of 2 electrically separated metallizations 6. This embodiment shows that the metallization 6 can also be implemented beyond the edges of the carrier 3, i.e., can be matched to the topography of the carrier 3. Each metallization 6 is connected in a material - fitting manner to the conductor 4 at the first conductor end 8 by means of a sub - region on the side surface by means of a connecting portion 5. This embodiment can be used, for example, as a piezoelectric measuring element having a piezoelectric longitudinal effect, wherein the piezoelectric charge during force loading can be led out along the vertical axis of the column - shaped carrier 3 by means of the metallization 6. In the case where the carrier is implemented as a piezoelectric measuring element, the corresponding second end 9 of the conductor (not shown) is usually conductively connected to a charge amplifier or an impedance converter (both not shown).

[0075] For example, the system 36 is manufactured by providing a carrier 3 in a first step. The carrier 3 has a carrier surface 7, and in a second step, a first layer 1 is applied to this carrier surface. The first layer 1 is typically applied to the carrier surface 7 by sputtering (also known as cold cathode sputtering) or by evaporation. The shaping of the first layer 1 is achieved by masking (Maskierung) of the carrier surface 7 and / or by laser structuring. In a third step, a second layer 2 is applied to the first layer 1. The second layer 2 is typically also applied to the carrier surface 7 by sputtering or by evaporation. The shaping of the second layer 2 is achieved by masking of the carrier surface 7 and / or by laser structuring. The second layer can also be applied by means of an electroplating method. Laser structuring is also possible after the application of the first layer 1 and the second layer 2.

[0076] Unless otherwise stated, all numerical values regarding physical dimensions and properties refer to a temperature of 20 °C and a normal ambient pressure (normal pressure) of 101.3 kPa (kilopascals).

[0077] Embodiments having combinations of the features of the embodiments described herein are also explicitly included herein.

Claims

1. A system (36) comprising a carrier (3) and at least one metallization (6); wherein: The metallization (6) comprises at least a first layer (1) and a second layer (2); wherein the carrier is an oxide ceramic; wherein the carrier (3) has a carrier surface (7); wherein the first layer (1) is arranged between the carrier surface and the second layer (2); wherein the second layer (2) consists of a precious metal to at least 90% by weight; wherein the first layer (1) consists of a transition metal and / or a metal and / or a semimetal; characterised in that the first layer (1) is ultrasonically damped; and the first layer (1) has at least 10 -4 and a layer thickness of 500 nm to 4 μm.

2. System (36) according to the preceding claim, characterized in that The first layer (1) has a mechanical vibration frequency of at least 10 -4 The loss coefficient.

3. A system (36) according to any one of the preceding claims, characterized in that The first layer (1) has an elastic modulus between 60 GPa and 130 GPa; preferably between 80 GPa and 100 GPa.

4. A system (36) according to any one of the preceding claims, characterized in that The first layer (1) consists of a metal or an alloy which has a negative standard enthalpy of formation for the oxide of the relevant metal or alloy in a temperature range of up to 350° C.; and the first layer (1) is made of bronze or a copper alloy.

5. The system (36) according to any one of the preceding claims, characterized in that The carrier (3) has an elastic modulus between 60 GPa and 120 GPa and has a -6 K -1 With α=20·10 -6 K -1 between α and α = 6·10 -6 K -1 With α=18·10 -6 K -1 between α=12·10 -6 K -1 With α=18·10 -6 K -1 or the carrier (3) is an oxide ceramic having an elastic modulus between 90 GPa and 110 GPa and α=12·10 -6 With α=18·10 -6 K -1 The thermal longitudinal expansion coefficient between.

6. A system (36) according to any one of the preceding claims, characterised in that The first layer (1) is implemented as an adhesion promoter for the carrier surface (7) and is connected to the carrier surface (7) in a material-bonded manner; and the first layer (1) has a value of α=5·10 -6 K -1 With α=18·10 -6 K -1 The coefficient of thermal expansion between.

7. A system (36) according to any one of the preceding claims, characterized in that The second layer (2) has a layer thickness of between 20 nm and 300 nm.

8. A system (36) according to any one of the preceding claims, characterised in that The second layer (2) has a high mechanical stability and is produced, for example, from platinum or a platinum alloy having a platinum content of at least 90% by weight.

9. The system (36) according to any one of the preceding claims, characterized in that The first layer (1) is a bronze alloy having copper, tin and nickel; wherein the first layer (1) preferably has 84.5% by weight to 87.5% by weight of copper, 11% by weight to 13% by weight of tin, 1.5% by weight to 2.5% by weight of nickel; and wherein the first layer (1) has a maximum of 16% by weight of elements other than copper, tin and nickel.

10. A system (36) according to the preceding claim; wherein: The elastic modulus of the first layer (1) deviates from the elastic modulus of the carrier (3) by no more than 20%, preferably by no more than 10%.

11. A system (36) according to the preceding claim; wherein: The thermal expansion coefficient of the first layer (1) deviates from the thermal expansion coefficient of the carrier (3) by no more than 20%, preferably by no more than 10%.

12. A system (36) according to the preceding claim; wherein: The carrier (3) is a piezoelectric material, preferably a piezoelectric crystal.

13. The system (36) according to any one of the preceding claims, characterized in that The second layer (2) has an elastic modulus greater than 150 GPa.

14. The system (36) according to any one of the preceding claims, characterized in that The second layer (2) has a high scratch resistance, wherein the second layer (2) has a Mohs hardness of >3.

15. A contact system (364); wherein: The contact system (364) comprises at least one conductor (4) and a system consisting of a carrier (3) and at least one metallization part (6) according to any one of claims 1 to 12; the conductor (4) has a first conductor end (8) and a second conductor end (9); wherein the first conductor end (8) is connected to the second layer (2) by material fit; wherein the second layer (2) has good bondability with the conductor (4), wherein the conductor (4) is, for example, a bonding wire made of gold or a bonding wire made of aluminum.

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