EP2352709A2

EP2352709A2 - Composite material, method for producing a composite material and adhesive or binding material

Info

Publication number: EP2352709A2
Application number: EP09768229A
Authority: EP
Inventors: Xinhe Tang; Helmut Hartl; Andreas Frischmann; Ernst Hammel
Original assignee: Curamik Electronics GmbH
Current assignee: Rogers Germany GmbH
Priority date: 2008-10-29
Filing date: 2009-10-20
Publication date: 2011-08-10
Also published as: KR101319755B1; DE102009041574A1; CN102292308A; JP2012507459A; WO2010049771A2; JP5656088B2; KR20110081889A; WO2010049771A3; US20110274888A1

Abstract

The invention relates to a composite material consisting of at least one ceramic layer or at least one ceramic substrate and at least one metallisation formed by a metallic layer on a surface side of the at least one ceramic substrate.

Description

Composite material, method of making a composite, and adhesive or bonding material

The invention relates to a composite material according to the preamble of claim 1 and to a method for producing such

Composite material according to the preamble of claim 28 and to a bonding material or an adhesive according to the preamble of claim 51.

The production of composite materials is also known as printed circuit boards in the form of metal-ceramic substrates according to the so-called DCB process (also DC B substrates). Here, the metallization required for the formation of traces, terminals, etc., on a ceramic, e.g. on an aluminum-oxide-ceramic by means of the so-called "DCB-method" (Direct-Copper-Bond-Technology) applied, using the metallization forming metal or copper foils or metal or copper sheets on their surface sides a layer or a coating (reflow layer) of a chemical compound of the metal and a reactive gas, preferably oxygen.

In this method, for example, in US-PS 3744 120 or in DE-PS 23 19 854 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 joined together, by melting the metal or copper substantially only in the region of the reflow layer or oxide layer.

This DCB method then indicates e.g. following 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 ⁰ C, for example to about 1071 ⁰ C;

> Cool to room temperature.

Also known is the so-called active soldering method (DE 22 13 1 15, EP-A-153 618) for joining metallization-forming metal layers or metal foils, in particular also copper layers or copper foils with the respective ceramic material. In this method, which is used especially for the production of metal-ceramic substrates, at a temperature between about 800 - 1000 ⁰ C, a connection between a metal foil, such as copper foil, and a ceramic substrate, such as aluminum nitride ceramic, using a Brazing produced, which in addition to a main component such as copper, silver and / or gold also contains an active metal. This active metal, which is, for example, at least one element of the group Hf, Ti, Zr, Nb, Ce, establishes a connection between the solder and the ceramic by chemical reaction, while the connection between the solder and the metal is a metallic braze joint ,

Object of the present invention is to show a composite material which can be made particularly simple and inexpensive, while maintaining the best possible thermal properties. To solve this problem, a composite material according to claim 1 is formed. A method for producing this material is subject matter of claim 28. A bonding material or adhesive is the subject of claim 51.

For the purposes of the invention, nanofiber material generally means nanofibers and / or nanotubes and in particular also carbon nanofibers and / or nanotubes. Suitable nanofibers are, for example, those fibers which are sold under the name ENF-100-HT, HTP-150F-LHT, HTP-110FF-LHT and HTP-110F-HHT by Electrovac GmbH, A-3400 Klosterneuburg, Austria.

Further nanofibers usable in the invention, which are likewise offered by Electrovac GmbH, A-3400 Klosterneuburg, Austria, are given in Table 1 below.

Table 1

Nano fiber type:

AGF as grown

PSF pyrolytic stripped carbon nanofiber

LHT baked at ~ 1000 ⁰ C

HHT annealed at ~ 3000 ⁰ C

HTE annealed at ~ 1000 ⁰ C at EVAC

GFE baked and graphitized at ~ 3000 ⁰ C at EVAC

Accordingly, mean:

The nanofibers or nanotubes are for the most part, i. in the majority a length in the range between 1 to 100 //, a thickness in the range between about 1 nm and 300nm, for example in the range between about 1 nm and 100nm or in the range between about 50nm and 150nm or in the range between about 1nm to 100nm, for example in the range between about 3nm to 75nm.

The composite material according to the invention is preferably a multilayer material and preferably a multilayer material or substrate suitable as a printed circuit board for electrical circuits, modules, etc. comprising at least one plate-shaped carrier substrate, preferably ceramic and / or glass substrate, at least on one surface side of an electrically insulating material from at least one example Metallization formed by a metal plate or foil, which is connected via the adhesive or bonding layer to the substrate.

In general, the metallization consists for example of copper, aluminum and / or of another metal or of a metallic alloy and / or a metallic composite and / or multilayer material, for example of a copper or aluminum alloy and / or of a copper / aluminum composite material and / or an alloy as commonly used in the manufacture of metal resistors. The composite material according to the invention has the advantage of a simple and inexpensive production. Another advantage is that in particular the thickness of the metallizations can be chosen arbitrarily within wide limits, for example in the range between about 0.01 mm to 4 mm. Furthermore, a compensation of different coefficients of thermal expansion of the materials of the metallization and of the ceramic substrate is achieved via the layer formed by the adhesive or bonding agent. In particular, with appropriate orientation of at least part of the nanofiber material in the bonding layer parallel or approximately parallel to the joined surfaces, an effect compensating the thermal expansion of the metallization can be achieved.

The composition and / or layer thickness of the at least one adhesive or bonding layer between the at least one metallization and the carrier substrate, e.g. Ceramic substrate, for example, chosen so that the thermal resistance that this adhesive or bonding layer in an axial direction perpendicular to the

Surface sides of the metallization and / or the carrier substrate is equal to or smaller than the thermal resistance, which has the carrier substrate in this axial direction. For this purpose, on the one hand, the proportion of nanofiber material is selected to be high and is, for example, 5 to 30 percent by weight, based on the total mass of the adhesive or bonding layer. Furthermore, the thickness of this adhesive or bonding layer is selected such that the surface sides of the at least one metallization and the carrier substrate which are connected to one another are spaced apart by a maximum of 50 μm, preferably approximately 5 μm to 25 μm, the effective thickness of the Bonding layer so maximum 50 microns, but preferably about 5 .mu.m to 25 // m amounts. This small distance or this small effective thickness of the adhesive or

Bonding layer is possible by using the nanofiber material consisting of the very thin nanofibers and / or nanotubes, the length of these nanofibers or nanotubes being at least largely in the range between 1 and 100 μm, for example in the range of 10 μm. Although nanofibers or nanotubes have a high thermal conductivity in the direction of their longitudinal extension, but the thermal conductivity is only limited radially to the longitudinal extension and also the respective adhesive or bonding layer should have only a small effective thickness to reduce the thermal resistance, are in a preferred embodiment of Invention with each other via the adhesive or

Bonded bonding surfaces provided with a surface roughness and that at least one metallization having a surface roughness approximately in the range between about 1μm and 7μπ \ and the ceramic and / or glass substrate having a surface roughness in the range of about 4 to 10 // m. The cavities formed by the surface roughness thus create a space in which the nanofiber material can spread or orient with its longitudinal extension perpendicularly or at least obliquely to the surface sides connected to one another via the adhesive or bonding layer, so that the adhesion of the nanofiber material - or bonding layer desired high thermal conductivity is reached.

As a matrix material for the respective adhesive or bonding layer, a plastic is used which, in conjunction with the nanofiber material, ensures a sufficiently high adhesive strength between the at least one metallization and the adjacent carrier substrate, for example an adhesive strength in the range of at least 25 N / mm ² (area of the bonded metallization). The matrix material is further selected so that the hardened or bonded adhesive or bonding layer also has a sufficiently high temperature resistance, so that the metal-ceramic substrate in particular as a base or circuit board or as a metal-ceramic substrate for electrical circuits or Modules is useful, their assembly with the electrical and electronic components, at least in the industrial manufacturing is done exclusively with lead-free electronic solders, at soldering temperatures in the range of about 265 to 345 ° C. As a matrix material, therefore, for example, an epoxy resin or an epoxy-based plastic is suitable. The production of structured metallizations for the formation of conductor tracks, and / or contact surfaces and / or mounting surfaces, etc., can be done in different ways, for example, that after the bonding of the relevant metallization, ie after curing of the metallization with an adjacent layer, eg is patterned with the adjacent carrier substrate or bonding to the adjacent ceramic substrate bonding or bonding layer by a conventional technique, for example, with a masking and etching technique and then the between the structuring generated metal areas (traces, contact surfaces, mounting surfaces, etc.) remaining Remains of the adhesive and bonding material are removed, for example, mechanically or erosive by sandblasting, by lasers, etc.

In order to avoid this post-processing, there is still the possibility of structurally applying the adhesive or bonding material to the surface to be provided with the structured metallization, namely in the form of structured regions which correspond in shape and position to the structured regions of the metallization. The metallization to be patterned is then bonded over the structured regions of the adhesive or bonding material. After curing or setting of the adhesive or bonding material, the metallization is patterned by a suitable technique, for example by masking and etching, so that a structured, bonded metallization is obtained, without residues of adhesive and bonding material between the metal regions of this metallization. In general, the application of the adhesive and bonding material via masks and / or screens and / or by spraying and / or by rolling and / or by spin coating.

Furthermore, it is possible to produce the layout of the structured metallization, ie the metal elements or pads forming the metal regions of the structured metallization, for example by punching from a suitable metallic flat material, eg from a metal foil, and then using the adhesive or bonding material at one the structured metallization too This surface area is then either provided over the entire surface with a layer of the adhesive or bonding material and this material is removed after bonding, ie after curing or setting, between the metal areas of the structured metallization by suitable means, or that Adhesive and bonding material on the surface area provided with the structured metallization again structured, that is, is applied only where it is necessary for bonding a metal portion of the patterned metallization. Furthermore, it is also possible to apply the adhesive or bonding material exclusively to the metal elements or pads forming the structured metallization.

Furthermore, it is possible to carry out the composite material according to the invention as a multi-substrate, for example in the form of at least two interconnected via at least one adhesive or bonding layer individual substrates, of which then at least one turn as a composite material or metal ceramic and / or glass composite material or substrate is executed.

The use of the nanofiber material in the adhesive or bonding layer 5 or in the adhesive or strip material not only improves the thermal conductivity of the adhesive or bonding layer, but also results in a reduction of the thermal expansion coefficient and the elastic properties of the nanofiber material Bonding and bonding layer 5, in particular in the form that between the respective metallization 3 and 4 and the carrier substrate 2 is made a very rigid connection. In this way it is then also possible, by appropriate choice of the material for the carrier substrate 2, to adapt the composite material 1 to a total of its thermal expansion coefficient to those of semiconductor material and thereby temperature-induced mechanical stresses between mounted on the composite material or on a printed circuit board made of this composite semiconductor devices or To reduce semiconductor chips and the composite material and defects of the respective electronic circuit or module caused by temperature-induced mechanical stresses.

Preferably, the proportion of nanofiber material in the adhesive or bonding material is selected so that a sufficiently thin processing of this material is possible, namely to form an adhesive or bonding layer having a thickness of less than 25 .mu.m, preferably in the range between 4 and 25 .mu.m, and indeed, among others to achieve the lowest possible thermal resistance for the adhesive or bonding layer, e.g. in a substrate used as a printed circuit board and thus to achieve the lowest possible thermal resistance for the composite material or the substrate as a whole.

Due to the nanofiber material and the small thickness, the very thin adhesive and bonding layer in the manner described above no or only a slight elasticity and thereby improves the thermal shock resistance and durability of semiconductor circuits and modules. Furthermore, due to the small thickness, such surfaces or volumes of the adhesive or bonding layer to which (surfaces or volumes) external media, e.g. Water or moisture could be extremely reduced, which also contributes significantly to the long-term life of the composite material or an electrical circuit or module produced using this composite material.

The nanofiber material is preferably cleaned before mixing into the plastic matrix, for example, baked out, and in particular also with the Zeil impurities, in particular metallic impurities and / or catalysts to remove, and in particular also those which used the plastic material used for the matrix and / or their properties could influence.

In addition to the nanofiber material, the adhesive or bonding material contains, for example, further additives or fillers, in particular also chemically neutral additives or fillers, such as carbon or graphite, ceramics, etc.

In a further development of the invention, the composite material, for example, is formed so that the carrier substrate is plate-shaped or substantially plate-shaped, and / or that the carrier substrate is a ceramic and / or glass layer or a ceramic and / or glass substrate, for example, from an alumina and / or aluminum nitride and / or silicon nitride ceramic and / or that the at least one metallization in the region of the adhesive or bonding layer of the adjacent layer is a distance of less than 50 microns, preferably a distance of the order of a maximum of 25 microns or between about 5 / / m and 25μm, and / or that at the top of the carrier substrate, a first metallization and at the

The underside of the carrier substrate, a second metallization are provided, and that at least one of these metallizations is structured, and / or that the at least one metallization with the carrier substrate connecting adhesive or bonding layer with respect to their layer thickness and / or

A composition is selected such that the thermal resistance that the adhesive or bonding layer has in an axial direction perpendicular to the adjoining surface sides of the metallization and of the carrier substrate is less than or at most equal to the thermal resistance that the carrier substrate has in this axial direction, and / or that the nanofiber material is a carbon nanofiber material and / or that the nanofiber material is contained in a proportion of 5 to 30 weight percent in the adhesive or bonding material, based on the total weight of this material, and / or that the nanofiber material is formed by nanofibers and / or nanotubes, wherein preferably at least a majority of these nanofibers or nanotubes has a length in the range of between about 1 .mu.m and 100 .mu.m and a thickness in the range of about 1 nm to 300 nm or in the range between about 50nm to

150 nm or in the range between about 1 nm to 100 nm, for example in the range of about 3 nm to 75 nm, and / or that the at least one metallization and / or the at least one carrier substrate in the region of the adhesive or bonding layer with a

Surface roughness are provided, namely the metallization, for example, with a surface roughness in the range between about 1 micron and 7μu \ and / or the carrier substrate, for example, with a surface roughness in the range 4-10 // m, and / or that the surface roughness mechanically and / or physically and / or is chemically generated, for example by sandblasting and / or by

Grain boundary etching and / or by plasma treatment and / or by depositing a copper and another metal-containing layer and then etching away the further metal, and / or that the bonding layer consists of an epoxy-based or epoxy resin-based matrix, and / or that the adhesive or bonding layer or the adhesive layer forming this layer or

Bonding material further additives, for example flame retardant additives, e.g.

Contains halides or boron compounds, and / or that the plastic material formed the matrix of the adhesive or bonding material is selected such that the adhesive or bonding layer in the cured and / or set state has a temperature resistance of at least 220 ⁰ C, and / or that the at least one metallization at least in some areas from a metallic alloy and / or of a metallic composite and / or multi-layer material, for example of an aluminum / copper multilayer material, and / or that the at least one metallization is at least partially made of copper, from a

Copper alloy, made of aluminum, an aluminum alloy and / or of a metallic resistance material and / or at least one metallic foil, for example copper, a copper alloy, aluminum, an aluminum alloy and / or of the metallic resistance material is formed, and or that the at least one metallization has a thickness in the range between about 0.01 mm and 4 mm, for example between about 0.03 mm and 0.8 mm, and / or the at least one carrier substrate has a thickness in the range between about 0.1 mm and 1 , 2mm, for example, between about 0.25mm and 1.2mm, and / or that the at least one metallization over the adhesive or bonding layer with an adhesive strength (peel-off strength) of at least 1 N / mm, preferably with a Adhesive strength of at least 2.5 N / mm with the adjacent layer, for example, connected to the adjacent carrier substrate, and / or that the at least one metallization z ur formation of structured metal areas, for example in the form of conductor tracks, contact and / or mounting surfaces is structured, and that the adhesive and bonding layer between adjacent structured metal areas is not provided or removed, and / or that the metallization forms at least on one surface side of the at least one carrier substrate an electrical connection projecting beyond an edge region of the composite material or the carrier substrate, for example a connection generated from a leadframe, and / or the at least one carrier substrate and / or the at least one Metallization via an adhesive or bonding layer of the adhesive or bonding material with a leadframe or with webs of this lead frame is connected, and / or that it is formed as a multi-substrate of at least two individual substrates, and that the individual substrates on at least one of the adhesive or Bonding material formed adhesive or bonding layer are joined together, and / or that the at least one adhesive or bonding layer is free of gas and / or vapor bubbles, in particular air bubbles or the volume fraction of such bubbles based on the total volume of at least one adhesive or bonding layer hoch 0.1% by volume, and / or that the adhesive or bonding layer also contains pulverulent additives, such as carbon,

Graphite, ceramic and / or metallic additives, and / or that the nanofiber material is a metal-free or essentially metal-free nanofiber material, in particular a nanofiber material without Ni, Fe and / or Co and / or a chemically and / or thermally pretreated nanofiber material, and / or or that the total proportion of the nanofiber material and any further constituents in the plastic matrix of the adhesive or bonding layer is selected such that the glass transition temperature of the adhesive or bonding material or the plastic matrix is at least 150 ⁰ C and / or at least increased by 25% compared to the glass transition temperature of the plastic matrix forming plastic, for example epoxy, and / or that the total content of nanofiber material and any other additives about 25% by weight based on the total mass of the adhesive or Bonding layer is, and / or that the total amount of nanofiber material and any other additives is chosen so that a thickness of at least one adhesive or bonding layer is less than 25 microns possible, and / or that the total content of nanofiber material and ggs. further fillers is selected so that the thermal conductivity of the adhesive or bonding layer is greater by at least a factor of five than the thermal conductivity of the plastic matrix forming plastic, for example, greater than IW / mK, the above features each individually or can be provided in any combination.

In a further development of the invention, the method for producing a composite material, for example, is designed so that the metal layer or metal foil and / or the carrier substrate are roughened before bonding to their surface sides to be joined, preferably to achieve a roughness of about 1 micron to 5 microns for the metal layer or film and / or to achieve a roughness of about 4 .mu.m to 10 .mu.m for the carrier substrate, and / or that the surface roughness mechanically and / or physically and / or chemically generated, for example by sandblasting and / or by pimples and / or by grain boundary etching and / or by plasma treatment and / or by depositing a metal layer consisting of the metal of the metallization and another metal and then removing the further metal by etching, and / or that an adhesive or bonding material, which in addition to the nanofiber material further additives, such as flame retardant additives, eg halides, boron and / or nitride compounds, etc., and or in that the metallization connected via the adhesive or bonding layer to an adjacent layer, for example to the carrier substrate, is structured, and / or that the adhesive or bonding material extends over the whole area onto the region of the metallization-adjacent layer, for example the carrier substrate is applied, and that after the structuring of the metallization, the adhesive or bonding layer between the metal regions of the structured metallization is removed, for example mechanically, for example by sandblasting, by laser treatment or plasma treatment, and / or that the adhesive or bonding material before application the at least one metallization to be patterned in a form and position corresponding to the shape and position of the metal regions of the structured metallization on the metallization to be bonded or on the metal layer forming it and / or on the surface region of the adjacent layer to be metallized, for example Carrier substrate is applied, and / or that for generating at least one structured metallization on a surface side of a subsequent layer, for example, on a surface side of the carrier substrate, the layout or the metal areas of the structured metallization forming, for example by punching metal elements or pads in one of the structured metallization be provided corresponding layer and be connected using the adhesive and bonding material with the subsequent layer, and / or that the provision of the metal elements or pads by arranging these elements in a mask or form and / or by applying the same

Elements on a subcarrier or a carrier material takes place, and / or that the adhesive or bonding material is applied over the entire surface of the provided with the structured metallization surface region of the adjacent layer, and that after bonding, i. after setting and / or

Curing the adhesive or bonding material between the metal areas of the structured metallization is removed, for example mechanically, for example by sandblasting, and / or by laser or plasma treatment, and / or that the adhesive or bonding material to be provided with the structured metallization Surface side of the subsequent layer in a metal surfaces or pads of the patterned metallization corresponding shape and position structured and / or is applied to the connected to the adjacent layer surface side of the provided metal elements, and / or that the at least one metallization at least in partial areas of a Layer or foil made of copper or aluminum or of a metallic resistance material, and / or that the at least one metallization at least partially made of copper and / or aluminum and / or a metallic alloy, for example of a copper alloy or Alum iniumium alloy, and / or of a metallic composite and / or multilayer material, eg of an aluminum / copper multilayer material, for example in the form of a metallic foil, and / or that the composite material after applying the at least one

Metallization in particular also to improve the thermal conductivity by

Annealing is, for example, at a temperature equal to or higher than that used for setting the adhesive and bonding material

Bonding temperature, and / or that the adhesive and bonding material on the carrier substrate using

Masks, in particular shadow masks, stencils, screens, by spraying, rolling and / or spin coating is applied, and / or that the full-surface and / or structured application of the adhesive or

Bonding material using at least one mask and / or stencil and / or by screen printing, and / or that the bonding and / or the aftertreatment or annealing are carried out under pressure, and / or that the mixing of the adhesive or bonding material and / or or the bonding done so that the adhesive or bonding material formed by the adhesive or bonding material

Bond layer at least in the finished composite material free of gas and / or

Vapor bubbles, in particular air bubbles, is the volume fraction of such bubbles in the adhesive or bonding layer based on the total volume of this layer is at most 0.1% by volume, and / or that the adhesive or bonding layer and powdery additives such as carbon,

Contains graphite and / or ceramic and / or metallic additives, and / or the nanofiber material is a metal-free or substantially metal-free nanofiber material, in particular a nanofiber material without Ni, Fe and / or Co and / or a chemically and / or thermally pretreated nanofiber material, and / or that the total proportion of the nanofiber material and any further

Components in the plastic matrix of the adhesive or bonding layer is selected such that the glass transition temperature of the adhesive or bonding material or the plastic matrix is at least 150 ⁰ C and / or at least 25% compared to the glass transition temperature of the plastic matrix forming plastic, For example, epoxy is increased, and / or that the total content of nanofiber material and any further additives about 25% by weight based on the total mass of the adhesive or bonding layer, and / or that the total amount of nanofiber material and any other additives is selected so that a thickness of at least one adhesive or bonding layer smaller than 25 microns is possible, and / or that the total content of nanofiber material and ggs. further fillers is selected so that the thermal conductivity of the adhesive or bonding layer at least by a factor of four, preferably at least by a factor of five is greater than the thermal conductivity of the plastic matrix forming plastic without nanofiber material and ggs. has further fillers, for example, greater than 1 W / mK, wherein the aforementioned features may be used individually or in any combination.

In a further development of the invention, the bonding material is designed, for example, such that the nanofiber material is a carbon nanofiber material, and / or that the nanofiber material is present in an amount of from 5 to 30% by weight in the adhesive. or bonding material, based on the total weight of this

Material, and / or that the nanofiber material of nanofibers and / or nanotubes is formed, wherein preferably at least a majority of these nanofibers or nanotubes has a length in the range between about 1 .mu.m and 100 .mu.m and a thickness in the

Range between 1 nm to 300nm or in the range between about 50nm to

150nm or in the range between about 1 nm to 100nm, for example in the range of about 3nm to 75nm, and / or that the matrix is epoxy based or epoxy resin based, and / or other additives, for example Flammhemmende additives, eg halides or boron compounds, and / or that the plastic material forming the matrix is selected such that it has a temperature resistance of at least 220 ⁰ C in the cured and / or hardened state, and / or that it powdery additives, such as carbon, graphite, ceramic and / or metallic additives, and / or that the nanofiber material is a metal-free or substantially metal-free

Nanofiber material, in particular a nanofiber material without Ni, Fe and / or Co and / or a chemically and / or thermally pretreated nanofiber material, and / or that the total content of the nanofiber material and possibly further

Components is selected such that the glass transition temperature of the bonding material or

Adhesive or the plastic matrix is at least 150 ⁰ C and / or at least 25% compared to the glass transition temperature of the plastic matrix forming Plastic, for example, epoxy is increased, and / or that the total content of nanofiber material and any other additives about 25% by weight based on the total mass of the adhesive or bonding layer, and / or that the total content of nanofiber material and ggs. further fillers is selected so that the thermal conductivity of the bonding material or adhesive is greater by at least a factor of five than the thermal conductivity of the plastic matrix forming plastic, for example, greater than 1W / mK, wherein the aforementioned features each individually or in Any combination can be provided.

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 metal-ceramic composite material in the form of a metal-ceramic substrate according to the

Invention; Fig. 2 in an enlarged partial view of the adhesive or bonding layer between a

Metallization and a carrier substrate in the form of a ceramic substrate of the

Metal-ceramic substrate of Figure 1; Fig. 3 in a simplified representation and in side view of a curved metal-ceramic substrate;

4 to 8 each show a simplified representation of different process steps in the production of a metal-ceramic substrate with structured metallization on the substrate top side;

9 shows a simplified representation of a plan view of a partial length of a leadframe together with metal-ceramic substrates provided on the leadframe;

10 shows a simplified representation and in section of one of the leadframe provided on metal-ceramic substrates.

11 is a simplified representation in side view of a two metal-ceramic substrates existing multiple substrate.

FIG. 12 shows an enlarged sectional view of the ceramic substrate together with a structured metal region; FIG. Fig. 13 in a simplified representation of the form of a structured order of

Adhesive or bonding material for bonding a metallization, preferably a structured metallization;

14 is a schematic partial representation and in plan view a mask for the metered application of the adhesive or bonding layer forming adhesive or bonding material.

15 is a schematic representation in side view of a measuring arrangement for determining the adhesive strength (peel-off strength) of the applied to the carrier layer metallization.

The metal-ceramic composite material or metal-ceramic substrate generally designated 1 in FIG. 1, which is suitable as a printed circuit board for electrical circuits or modules, essentially consists of a plate-shaped carrier substrate 2 in the form of a ceramic substrate made of an aluminum oxide Ceramic, aluminum nitride ceramic or silicon nitride ceramic. On both surface sides of the substrate, a metallization 3 and 4 formed by a metal foil, for example by a foil made of copper or a copper alloy, is provided, which is connected to the substrate 2 over an adhesive or bonding layer 5 formed by an adhesive or bonding material. In the embodiment illustrated in FIG. 1, the metal-ceramic substrate is formed symmetrically with respect to an imaginary substrate center plane, specifically in that both metallizations 3 and 4 as well as the two adhesive and bonding layers 5 each have the same thickness, the two Metallizations 3 and 4 are each made of the same metal, namely copper and also for the adhesive and bonding layers 5 the same adhesive or bonding material is used.

The adhesive or bonding material for the adhesive or bonding layers 5 essentially consists of a plastic matrix suitable as an adhesive, which i.a. Carbon nanofiber material contains, for example, based on the total weight of the adhesive or bonding material, a proportion of about 5 to 30% by weight of nanofiber material, and optionally further additives, for example in the form of thermally conductive substances, e.g. Graphene and / or graphite and / or in the form of flame retardant additives, e.g. Halides, boron compounds, but already the nanofiber material acts flame retardant, can be dispensed with a further flame retardant additive as a matter of principle.

In a preferred embodiment, the nanofiber material consists at least essentially of a carbon nanofiber commercially available under the name "Pyrograph III." This is baked out at 3000 ^° C. prior to mixing into the matrix and, if appropriate, prior to pretreatment.

The material used for the matrix is selected so that the respective adhesive or bonding layer 5, which is cured, for example, at room temperature or at an elevated temperature, for example at a temperature in the range between 120 ⁰ C and 180 ⁰ C, a sufficiently high thermal stability or one sufficiently high decomposition temperature, so that the metal-ceramic substrate 1 is still stable when used as a printed circuit board at the high soldering temperatures in the range of about 265 - 345 ° C, as they are today's electronic solders, for example on Sn / Ag, Sn / Cu or Sn / Ag / Cu base require. For the matrix thus a plastic material is appropriate, which is stable at least at 350 ⁰ C for 5 minutes. However, since the soldering temperature is only used for a short time when soldering, a temperature resistance of the adhesive or bonding layer is at least 220 ⁰ C sufficient.

The matrix material is primarily a plastic based on epoxy or epoxy resin. To u.a. To achieve optimum incorporation of the nanofiber material in the matrix material, for example, a solvent is used. Triethyleneglycol monobutyl ether is particularly suitable for this purpose.

The thickness of the substrate 2 is for example in the range between 0.1 to 1.2 mm, for example in the range between 0.38 and 1 mm. In principle, the thickness of the metallizations or of the metal or copper layers or foils forming these metallizations 3 and 4 can be chosen arbitrarily, for example in the range between 0.01 mm and 4 mm.

The thickness of the respective adhesive or bonding layer 5 is selected, for example, such that the thermal resistance that the bonding layer 5 has in an axial direction perpendicular to the surface sides of the metal-ceramic substrate 1 is less than or at most equal to the thermal resistance has the substrate 2 in this axial direction. For the two adhesive or bonding layers 5, this also results in a layer thickness of not more than 50 μm, even taking into account the considerably reduced thermal resistance due to the high proportion of carbon nanofiber material, and preferably a layer thickness of less than 25 μm, for example in the range between 5 μm and 25μm. The desired reduction of the thermal resistance for the adhesive or bonding layers 5, however, can only be achieved if, despite the greatly reduced thickness of the bonding layers 5 or despite the greatly reduced distance between the mutually facing surface sides of the substrate 2 and the respective metallization 3 and 4 respectively the individual nanofibers or nanotubes of the carbon

Nanofasermaterials are oriented so that they form with their longitudinal extent a heat-conducting bridge between the facing surface sides of the substrate 2 and the metallization 3 and 4, i. at least not oriented to a greater extent parallel or substantially parallel to these surface sides. In order to achieve this despite the small distance between the substrate 2 and the respective metallization 3 and 4, the mutually facing surface sides are formed according to the figure 2 with a roughness, namely the metallizations 3 and 4 or the copper foils forming these metallizations a surface roughness R3 / 4 in the range between about 1 // m and 7 // m and the substrate 2 with a surface roughness R2 in the range between about 4 // m and 10 microns, so that also nanofibers or nanotubes of greater length in the for optimal Heat transfer and thus optimal for a reduction of the thermal resistance within the recesses generated by the roughness in the direction of the thickness of the respective adhesive or bonding layer 5 can, as is schematically indicated in Figure 2 with the local lines 6.

The surface roughness, in particular also of the metallizations 3 and 4, can be produced in many different ways, for example by mechanical and / or physical and / or chemical treatment, for example by sandblasting and / or by pimpling, ie by treating the relevant surface with pumice particles , and / or plasma treatment and / or by grain boundary etching or by depositing a copper and at least one further metal-containing compound on the provided with the roughening Surface side and then removing the other metal by etching.

The surface roughness of the substrate 2 and of the metallizations 3 furthermore results in improved wetting of these surfaces during the application of the adhesive and bonding agent and improved strength of the bond between the ceramic substrate and the respective metallization, for example adhesive strength or peel-off strength of at least 1 N / mm, preferably at least 2.5 N / mm. This high adhesive strength is also decisive due to the orientation of the nanofiber material transversely to the adhesive or bonding layer 5.

The coefficient of thermal expansion of the metal-ceramic substrate 1 is greatly reduced compared with the coefficient of thermal expansion of the metallic material used for the metallizations 3 and 4, for example of the copper, and approximately corresponds to the thermal expansion coefficient of semiconductor material. This is achieved in that the adhesive and bonding layers 5 are extremely stable due to the nanofiber material and also an extremely stable connection of the metallizations 3 and 4 to the substrate 2 via this nanofiber material, so that the thermal expansion coefficient of the metal of the metallizations 3 and 4 both is greatly reduced by the nanofiber material, and in particular by the ceramic material of the substrate 2.

It can not be prevented that at least some of the nanofibers or the nanotubes of the carbon nanofiber material, in particular outside the recesses of the surface roughness between the mutually facing surface sides of the substrate 2 and the metallizations 3 and 4 with the longitudinal extent parallel or substantially parallel to these Surface pages is oriented. However, since the nanofibers or nanotubes have an extremely small diameter, even if by chance several nanofibers or nanotubes are stacked on top of each other, the extremely small distance between them can occur facing surface sides of the substrate 2 and the respective metallization 3 or 4 of only 50 microns or 5μm to 25μm are met.

The curing of the adhesive or bonding layers 5 forming material can for example be at room temperature or at an elevated temperature, for example at a temperature between room temperature and 120 ⁰ C - 180 ⁰ C, for example in an oven (also tunnel kiln), under pressure in a heated press, by induction, by thermal radiation, etc. Subsequently, a post-treatment is preferably carried out by annealing at an elevated annealing temperature over a longer period of time, for example at a temperature at least higher than the maximum temperature, in the subsequent use of the substrate as a printed circuit board in a circuit or module occurs. By the aftertreatment, among other things, the thermal conductivity can be improved, ie increased, for example by about 50%.

Especially when curing the adhesive or bonding material at elevated temperature and when applying only one metallization, for example, only the metallization 3 on top of the substrate 2 or when using different thickness metal or copper foils for the metallizations 3 and 4 can targeted a curvature for the metal-ceramic substrate 1 can be achieved, as shown schematically in Figure 3. This curvature is due to the fact that the metallic material or copper of the metallization 3 on the upper side of the substrate 2 when heating expands more strongly than the ceramic material of the substrate 2 and stronger after the setting of the adhesive or bonding layer 5 and the subsequent cooling Substrate 2 contracts so that a concave

Curvature of the metal-ceramic substrate 1 at the top formed by the metallization 3 results. If a curvature is not desired, this can be avoided by the above-described symmetrical design of the metal-ceramic substrate, but also in non-symmetrical design that the Curing the adhesive or bonding layers 5 at a reduced temperature, for example, at room temperature.

In order for the metal-ceramic substrate 1 to be suitable as a printed circuit board for electrical circuits or modules, it is necessary to structure at least one of the two metallizations, for example the metallization 3 for the formation of printed conductors, contact surfaces, mounting surfaces, etc.

FIGS. 4 to 7 show different methods for the production of the metal-ceramic substrate 1 with the structured metallization 3, wherein in these figures the bonding of the metallization 4 is not shown for the sake of simplicity, which for example occurs simultaneously with the bonding of the metallization 3 and / or at a different time of the procedure, eg only after the complete production of the structured metallization 3 with the metal regions 3.1 on the upper side of the metal-ceramic substrate 1.

In the method illustrated in FIG. 4, the adhesive or bonding layer 5 having the required thickness is first applied to the upper side of the substrate 2 (position a). Following this, the metallization 3 or the copper layer forming this metallization is placed unstructured (position b). In a next method step, after curing of the adhesive or bonding layer 5, the structuring of the metallization 3 to form the structured metal surfaces or regions 3.1 or the printed conductors, contact surfaces, mounting surfaces, etc. takes place, for example with the aid of a known masking and etching technique (Position c). In a further process step then the unneeded residues of

Adhesive or bonding layer 5 between the individual structured metal areas 3.1, ie where it is not covered by a structured metal area 3.1 removed, for example by sandblasting or by a plasma treatment, so that the adhesive or bonding material only as a structured adhesive or bonding layer 5.1 is present under the metal areas 3.1. In further process steps, a further treatment then takes place, for example by tempering and / or by deburring and / or by applying a surface layer of nickel and / or gold to the upper side of the structured metal regions 3.1.

FIG. 5 shows a further possibility of producing the metal-ceramic substrate with the structured metallization 3. In this method, the adhesive or bonding layer 5 is applied in a structured manner to the substrate 2 in such a way that the adhesive and bonding layer 5 or their structured areas 5.1 are located only where later a structured metal area 3.1 is provided (position a). Subsequently, the metallization 3 forming metal foil is placed unstructured and connected by curing of the structured areas 5.1 with the substrate 2 (position b). In a further method step, the structuring of the metallization 3 then takes place, for example with the aid of a masking and etching technique, i. the formation of the structured metal regions 3.1 in the form that the structured metal regions 3.1 are connected to the substrate 2 via the cured structured adhesive and bonding material 5.1.

The structured application of the adhesive or bonding material takes place, for example, using at least one mask, by screen printing or in another suitable manner. After the structuring of the metallization 3, further process steps of a subsequent treatment may in turn follow, as has been described above in connection with FIG.

FIG. 6 shows the essential method steps of a particularly environmentally friendly and efficient method. In this method, metal elements or pads 3.2 are first produced from a metal or copper foil, for example by stamping, the shape of which corresponds to the layout of the structured metallization 3 or the structured metal areas 3.1 correspond (position a). The metal elements 3.2 are then inserted into a mold or mask 7 or in recesses 8 provided there, wherein these depressions are adapted in their shape to the shape of the metal elements 3.2 such that each metal element 3.2 is received positively in its associated recess 8. The introduction of the metal elements 3.2, for example, by first arbitrarily laying on the mask 7 and then shaking the mask 7 in such a way that finally each metal element 3.2 is received in the matching recess 8 and projects beyond the recesses 8 having top of the mask 7 (Position b).

The substrate 2 is provided over the whole area with the adhesive or bonding layer 5 (position c) and then subsequently turned and placed with the adhesive and bonding layer 5 from above onto the mask 7 or onto the metal elements 3.2 held therein (position d). , After curing or setting of the adhesive or bonding layer 5, the mask 7 is removed, so that then the structured metalizations 3.1 forming metal elements 3.2 are held on the substrate 2 via the continuous adhesive or bonding layer 5 and after turning the substrate. 2 the state shown in the position e is reached. In a further method step, the adhesive or bonding layer 5 between the structured metal regions 3.1 is removed, for example by sandblasting and / or by a plasma treatment (position f), so that the metal regions 3.1 are again held on the ceramic substrate via the structured adhesive and bonding layer 5.1 , In further process steps, for example, an after-treatment is again carried out, as described above in connection with FIG. 4.

This method is particularly efficient and environmentally friendly, since a removal of metal or copper by etching to achieve the structured metal areas 3.1 is not required, the metal elements or pads later forming metal areas 3.1 forming metal elements or pads 3.2 are rather time-saving generated by stamping and also consuming to be prepared and / or disposal etch residues do not arise.

FIG. 7 shows a method in which, in the same way as described above for the method of FIG. 6, the metal elements 3.1 are first punched out of the metal foil and then introduced into the matching depressions 8 of the mask 7 (positions a and b). The application of the adhesive or bonding layer 5 to the substrate 2 is again structured in this method, i. it is done by a suitable technique, e.g. the screen printing process and / or using masks structured areas 5.1 formed where a metal element 3.2 to form a structured metal region 3.1 is to be connected to the substrate 2 (position c). Subsequently, the substrate 2 is placed turned on the arranged in the mask 7 metal elements 3.2 (position d), so that after curing of the adhesive or bonding material or the structured areas 5.1 and after removing the mask 7 and the turning of the substrate 2 is already the top-structured metal-ceramic substrate 1 is obtained (position e), which is then possibly fed to a post-treatment.

Above, it was assumed that the adhesive or bonding material in each case as a continuous adhesive or bonding layer 5 or as a structured adhesive or

Bonding layer 5.1 is applied to the substrate 2. In principle, it is also possible to apply the adhesive or bonding material to the metal foil 3 forming the copper foil or to the metal elements 3.2 already produced, for example, by punching out of a metal foil. A method of the latter type is shown schematically in Figure 8 in its main steps. Firstly, a carrier material 9, for example in the form of a carrier foil, is provided on which the metal elements or pads 3.2 forming the later structured metal regions 3.1 are provided in the required shape and spatial arrangement, ie the layout of the structured metallization 3 is applied. The carrier material 9 with the metal elements 3.2 becomes characterized, for example produces that a metal or copper foil laminated on one side with the carrier material 9 is structured by means of an etching or masking technique and / or the metal elements 3.2 punched out of a flat material are positioned in the required manner by means of at least one mask and subsequently with an adhesive with the carrier material 9 get connected.

On the side facing away from the substrate 9 surface side of the metal elements 3.2, the adhesive or bonding material is then applied, for example, with a screen printing technique, so that on each metal element 3.2, a region of the structured adhesive or bonding layer 5.1 is provided (position b). In a further method step, the substrate 2 is then placed on the metal elements 3.2 provided with the adhesive or bonding material (position c), specifically with metal elements 3.2 which are furthermore held on the carrier material 9. After curing of the adhesive or bonding material, the carrier material 9 is then removed by stripping, so that the structured on the top metal-ceramic substrate 1 is obtained.

FIG. 9 shows, in a very simplified schematic representation, a partial length of a leadframe 10, which in a known manner consists of a metallic flat material integrally with two sections 10.1 with positioning openings 11 each extending in the leadframe longitudinal direction and forming the longitudinal sides of the leadframe 10, with the two sections 10.1 ladder-like connecting continuous webs 10.2 and with the intermediate, subsequent connections forming web sections 10.3.

Between the sections 10.1 and the continuous webs 10.2 a plurality of metal-ceramic substrates 1 are provided exactly positioned, which form the basis for electrical circuits or modules and are equipped in a later step with corresponding components. The substrates 1 are, for example, metal-ceramic substrates produced by one of the methods described above or, for example, DCB substrates or substrates prepared by active soldering. The metallization on at least one surface side, for example the metallization 3, is structured to form conductor tracks, contact surfaces, mounting surfaces, etc. The web portions 10.3 are, as shown enlarged in the figure 10, connected with its free end to a surface side of the substrate 2, in the illustrated embodiment with that surface side of the substrate 2, on which the structured metal portions 3.1 are provided. The connection between the path sections 10.3 and the substrate 2 takes place via an adhesive or bonding layer 5 or structured adhesive or bonding layer 5.1. After loading the substrates 1 with the components and after encapsulating the substrates and the components with a mass forming the housing of the respective module, the web portions 10.3 are punched free in the manner known to those skilled in the art for the purpose of forming outwardly directed terminals or leads.

FIG. 11 shows, in a very simplified illustration and in side view, a multiple substrate 12, which consists of two individual substrates 13 and 14, which are each formed as metal-ceramic substrates and of which the individual substrate 14 is bonded to the individual substrate 13 or by gluing is attached. The individual substrate 13 in turn consists of the substrate 2 and the two metallizations 3 and 4 on the top and bottom of the substrate 2, wherein the metallization 3 is structured or has the structured metal regions 3.1. The individual substrate 14 also consists of a substrate 2, of an upper and lower metallization 3 and 4, wherein in turn one of the two metallizations, namely the upper, exposed metallization 3 is structured. The metallizations 3 and 4 are in the

Single substrates either using the DCB technique and / or by active soldering or by the adhesive and bonding layers 5 and the structured areas 5.1 connected to the respective substrate 2. The connection of the individual substrate 14 with the individual substrate 15 is effected via an adhesive or bonding layer 5. Wherever the adhesive or bonding material is structured, ie applied in the form of the structured regions 5.1, it is at least expedient to control the amount and / or distribution of the adhesive and bonding material in the respective structured region of the structured adhesive or bonding layer 5.1 to choose the shape of this area so that after bonding the entire gap formed between a structured metal area 3.1 and the substrate 2 is filled with the adhesive and bonding material and this material in any case up to the edge of the respective structured metal area 3.1 ranges, as shown schematically in Figure 12 for the structured adhesive or bonding layer 5.1 below the structured metal region 3.1, so in no case arise at the edge of the metallization or the structured metal region 3.1 cavities, as in the figure 12 with the line 15 is indicated.

In particular, such cavities 15 in outer, i. To avoid convex corner regions 16 of the respectively structured metal region 3.1 and at the same time to prevent the adhesive or bonding material from swelling over the edge of the respectively structured metal region 3.1 during bonding, the structured application of this material takes place in accordance with the broken line 17 of FIG Form that the order of the adhesive and bonding material is generally slightly smaller than the surface to be bonded of the structured metal region 3.1 and that the order of the adhesive or bonding material in the corners 16 more to the edge of the structured metal region 3.1 or to the edge region the area covered by the structured metal region 3.1 of the substrate 2 is brought, as indicated in the figure 13 with the jagged portion 17.1.

FIG. 14 shows in partial representation and in plan view a mask 18 in the form of a shadow mask, which essentially consists of a flat material 19, for example of a metallic flat material or of a flat plastic material, and with a multiplicity of through-going mask openings or holes 20 is provided, which in each case have the same hole size in the illustrated embodiment. The mask 18 is used to apply a predetermined amount of adhesive or bonding material to the respective carrier substrate 2 and is placed on this carrier substrate 2 for this purpose. Subsequently, the adhesive and bonding material is applied to the carrier substrate 2 facing away from the surface side of the mask 18, in such a way that in particular the openings 20 are completely filled with the adhesive and bonding material. With a scraper or doctor blade, the bonding or adhesive material not received in the openings 20 is removed from the mask 18. Subsequently, the mask 18 is removed from the carrier substrate 20, so that on the carrier substrate 2 then the mask openings 20 corresponding plurality of orders of adhesive and bonding material is present, each with a respective mask openings 20 corresponding volume. Subsequently, the adhesive and bonding material on the carrier substrate is distributed over the entire surface, at least where later the metallization 3 or 4 is to be applied. After the distribution is on the

Carrier substrate 2 is a layer of the adhesive and bonding material with the desired thickness obtained on the (layer) then the metallization 3 and 4 forming film is placed.

In a preferred embodiment, the flat material 19 has, for example, a thickness of 0.03 mm. The diameter of the circular holes 20 is 2.45 mm and the distance from hole to hole 1 mm, so that with this shadow mask 18 a layer thickness for the applied to the substrate 2 and there evenly distributed adhesive and material material of the order of gives about 14μm.

FIG. 15 shows a measuring arrangement 21 for determining the adhesive strength or peel-off strength of the respective metallization 3 or on the carrier substrate 2. The carrier substrate 3 is shown on which a surface side using the adhesive or bonding layer 5 Metallization, for example, the metallization 3 applied in the form of a metal strip predetermined width x such is that a partial length 3.1 of the metallization or of the metal strip protrudes like a flag from the top of the carrier substrate 2. On the part length 3.1, a tensile force according to the arrow F is exercised. The peel-off strength is defined as quotient peel-off strength = FPO / X, where

KPO is the force (indicated in N) which is at least required for stripping the metallization 3 or the metal or test strip formed by this metallization, and x (expressed in mm) is the width of the metal or test strip.

By appropriate composition of the adhesive or bonding material, an adhesive strength of at least 1 N / mm, preferably of at least 2.5 N / mm, is desired for the bonding material according to the invention.

The invention has been described above in various embodiments. It is understood that numerous other embodiments are conceivable without thereby departing from the inventive concept underlying the invention. Thus, the metallizations 3 and 4 may also consist, at least in some areas, of a layer or foil of a metal other than copper, for example of aluminum, or of a metallic resistance material.

It has been assumed above that the support substrate 2 is a ceramic substrate or a ceramic layer. In principle, the carrier substrate used may also be one made of glass, ie a glass substrate or else a carrier substrate which consists at least partly of ceramic and of glass, for example of a ceramic with a glass layer on at least one surface side. LIST OF REFERENCE NUMBERS

I metal-ceramic substrate 2 support substrate, e.g. Ceramic and / or glass layer

3, 4 metallization

3.1 structured metal area

3.2 metal ped

5 adhesive or bonding layer 5.1. structured area of the adhesive and bonding layer

6 line

7 mask

8 deepening

9 carrier material or carrier foil 10 leadframe

10.1 Leadframe section

10.2 Leadframe bridge

10.3 bridge section

I 1 positioning opening 12 multiple module

13, 14 single module

15 cavity

16 corner area

17 Form of structured adhesive and bonding material application 17.1 jib-like area

18 hole mask

19 flat material

20 Mask opening

21 Test device for determining the adhesive strength

Claims

Patent claims

1. Composite material with at least one carrier substrate (2) made of an electrically insulating material at least on one surface side

Ceramic and/or glass and with at least one metallization (3, 4) formed by a metal layer on a surface side of the at least one carrier substrate (2), characterized in that the at least one metallization (3, 4) is formed by an adhesive or bonding layer ( 5) made of an adhesive or bonding material which is in a plastic matrix at least one

Contains nanofiber material, is connected to the carrier substrate (2) and / or to an adjacent layer or an adjacent substrate.

2. Composite material according to claim 1, characterized in that the carrier substrate (2) is plate-shaped or substantially plate-shaped.

3. Composite material according to claim 1 or 2, characterized in that the carrier substrate (2) is a ceramic and / or glass layer or a ceramic and / or glass substrate (2), for example made of aluminum oxide and / or aluminum nitride and / or Silicon nitride ceramic is.

4. Composite material according to one of the preceding claims, characterized in that the at least one metallization (3, 4) in the area of the adhesive or bonding layer (5) is at a distance of less than 50 μm from the adjacent layer, preferably a distance of the order of magnitude of maximum

25μm or between about 5μm and 25//m.

5. Composite material according to one of the preceding claims, characterized in that on the top of the carrier substrate (2) a first metallization (3) and on the underside of the carrier substrate (2) a second Metallization (4) are provided, and that at least one of these metallizations is structured.

6. Composite material according to one of the preceding claims, characterized in that the at least one metallization (3, A) with the

The adhesive or bonding layer (5) connecting the carrier substrate (2) is selected in terms of its layer thickness and/or composition such that the thermal resistance that the adhesive or bonding layer (5, 5.1) has in an axial direction perpendicular to the adjoining surface sides of the metallization (3, A) and the carrier substrate (2), is less than or at most equal to the thermal resistance that the carrier substrate (2) has in this axial direction.

7. Composite material according to one of the preceding claims, characterized in that the nanofiber material is a carbon nanofiber material, and / or that the nanofiber material is contained in the adhesive or bonding material in a proportion of 5 to 30 percent by weight, based on the total weight of this material.

8. Composite material according to one of the preceding claims, characterized in that the nanofiber material is formed by nanofibers and / or nanotubes, preferably at least a large part of these nanofibers or nanotubes having a length in the range between approximately 1//m and 100 μm and a thickness of approximately Range between 1 nm to 300nm or in the range between about 50nm to 150nm or in the range between about 1 nm to 100nm, for example in the range from about 3nm to 75nm.

9. Composite material according to one of the preceding claims, characterized in that the at least one metallization (3, 4) and / or the at least one carrier substrate (2) in the area of the adhesive or bonding layer (5,

5.1) are provided with a surface roughness, namely the metallization, for example, with a surface roughness in the range between approximately 1//m and 7 μm and/or the carrier substrate, for example, with a surface roughness in the range between 4 - 10 μm.

10. Composite material according to claim 7, characterized in that the

Surface roughness is produced mechanically and/or physically and/or chemically, for example by sandblasting and/or by grain boundary etching and/or by plasma treatment and/or by depositing a layer containing copper and another metal and by subsequently etching away the further metal.

11.Composite material according to one of the preceding claims, characterized in that the bonding layer consists of an epoxy-based or epoxy-resin-based matrix.

12. Composite material according to one of the preceding claims, characterized in that the adhesive or bonding layer (5, 5.1) or the adhesive or bonding material forming this layer contains further additives, for example flame-retardant additives, for example halides or boron compounds.

13. Composite material according to one of the preceding claims, characterized in that the plastic material formed by the matrix of the adhesive or bonding material is selected such that the adhesive or bonding layer (5, 5.1) in the hardened and / or set state

Has temperature resistance of at least 220 ⁰ C.

14. Composite material according to one of the preceding claims, characterized in that the at least one metallization (3, 4) is made, at least in some areas, of a metallic alloy and/or of a metallic composite and/or multilayer material, for example made of an aluminum/copper multilayer material.

15. Composite material according to one of the preceding claims, characterized in that the at least one metallization (3, 4) consists at least partially of copper, of a copper alloy, of aluminum, of an aluminum alloy and / or of a metallic resistance material and / or of at least a metallic foil, for example made of copper, made of a copper alloy, made of aluminum, made of an aluminum alloy and/or made of the metallic resistance material.

16. Composite material according to one of the preceding claims, characterized in that the at least one metallization has a thickness in the range between approximately 0.01 mm and 4 mm, for example between approximately 0.03 mm and

0.8 mm and / or the at least one carrier substrate (2) has a thickness in the range between approximately 0.1 mm and 1.2 mm, for example between approximately 0.25 mm and 1.2 mm.

17. Composite material according to one of the preceding claims, characterized in that the at least one metallization (3, 4) over the adhesive or bonding layer (5, 5.1) with an adhesive strength (peel-off strength) of at least 1 N/mm, preferably with an adhesive strength of at least 2.5 N/mm is connected to the adjacent layer, for example to the adjacent carrier substrate (2).

18. Composite material according to one of the preceding claims, characterized in that the at least one metallization (3) is structured to form structured metal areas (3.1), for example in the form of conductor tracks, contact and / or mounting surfaces, and that the adhesive and Bond layer (5, 5.1) between adjacent structured metal areas (3.1) is not provided or removed.

19. Composite material according to one of the preceding claims, characterized in that the metallization forms, at least on one surface side of the at least one carrier substrate (2), an electrical connection protruding beyond an edge region of the composite material (1) or the carrier substrate (2), for example one made of a Leadframe (10) created connection (10.3).

20. Composite material according to one of the preceding claims, characterized in that the at least one carrier substrate (2) and / or the at least one metallization (3, A) via an adhesive or bonding layer (5, 5.1) made of the adhesive or bonding material a lead frame (10) or with webs (10.3) of this lead frame is connected.

21.Composite material according to one of the preceding claims, characterized in that it is formed as a multiple substrate from at least two individual substrates (13, 14), and that the individual substrates have at least one adhesive or bonding material formed by the adhesive or bonding material

Bond layer (5, 5.1) are connected to each other.

22. Composite material according to one of the preceding claims, characterized in that the at least one adhesive or bonding layer (5, 5.1) is free of gas and / or vapor bubbles, in particular air bubbles or the

Volume fraction of such bubbles based on the total volume of the at least one adhesive or bonding layer is at most 0.1 percent by volume.

23.Composite material according to one of the preceding claims, characterized in that the adhesive or bonding layer (5, 5.1) also contains powdery additives such as carbon, graphite, ceramic and / or metallic additives.

24. Composite material according to one of the preceding claims, characterized in that the nanofiber material is a metal-free or essentially metal-free nanofiber material, in particular a nanofiber material without Ni, Fe and / or Co and / or a chemically and / or thermally pretreated nanofiber material.

25.Composite material according to one of the preceding claims, characterized in that the total proportion of the nanofiber material and any other components in the plastic matrix of the adhesive or bonding layer (5, 5.1) is selected such that the glass transition temperature of the adhesive or bonding material or the plastic matrix is at least 150 ⁰ C and/or at least around

25% compared to the glass transition temperature of the plastic forming the plastic matrix, for example epoxy, and / or that the total proportion of nanofiber material and any other additives is approximately 25% by weight based on the total mass of the adhesive or bonding layer.

26. Composite material according to one of the preceding claims, characterized in that the total proportion of nanofiber material and possible further additives is selected so that a thickness of the at least one adhesive or bonding layer smaller than 25 μm is possible.

27. Composite material according to one of the preceding claims, characterized in that the total proportion of nanofiber material and ggs. Further fillers are selected so that the thermal conductivity of the adhesive or bonding layer (5, 5.1) is at least a factor of five greater than the thermal conductivity of the plastic matrix forming Has plastic, for example is greater than 1W/mK.

28. A method for producing a composite material with at least one plate-shaped carrier substrate (2) made of an electrically insulating material at least on one surface side, for example in the form of a ceramic and / or glass layer or a ceramic and / or glass substrate, and with at least one of a metal layer or metal foil formed metallization (3, 4) on at least one surface side of the carrier substrate (2), characterized in that the at least one metallization (3, A) is connected to the carrier substrate (2) by bonding with an adhesive or bonding material, which in a plastic matrix, for example in an epoxy-based plastic matrix, contains nanofiber material, preferably carbon nanofiber material.

29. The method according to claim 28, characterized in that the metal layer or metal foil and / or the carrier substrate (2) are roughened on their surface sides to be connected to one another before bonding, preferably to achieve a roughness of approximately 1 μm to 5 μm for the metal layer or film and/or to achieve a roughness of approximately 4μm to 10μm for the carrier substrate (2).

30. The method according to claim 29, characterized in that the

Surface roughness is produced mechanically and/or physically and/or chemically, for example by sandblasting and/or by pumice and/or by grain boundary etching and/or by plasma treatment and/or by depositing a metal layer consisting of the metal of the metallization and another metal and by subsequent removal of further metal by etching.

31. The method according to any one of the preceding claims, characterized by using an adhesive or bonding material which, in addition to the nanofiber material, contains further additives, for example flame-retardant additives, e.g. halides, boron and/or nitride compounds, etc.

32. Method according to one of the preceding claims, characterized in that the metallization (3) connected via the adhesive or bonding layer (5, 5.1) to an adjacent layer, for example to the carrier substrate (2), is structured.

33. The method according to claim 32, characterized in that the adhesive or bonding material (5) is applied over the entire area to the area of the layer adjacent to the metallization, for example of the carrier substrate (2), to be provided with the metallization (3, 4), and that after structuring the metallization (3) the adhesive or bonding layer (5) between the

Metal areas (3.1) of the structured metallization (3) is removed, for example mechanically, for example by sandblasting, by laser treatment or plasma treatment.

34. The method according to claim 33, characterized in that the adhesive or

Bonding material before applying the at least one metallization (3) to be structured in a shape and position corresponding to the shape and position of the metal areas (3.1) of the structured metallization on the metallization to be bonded or on the metal layer (3) forming it and/or on the surface area of the adjacent layer to be provided with the metallization, for example of the carrier substrate (2), is applied.

35. Method according to one of the preceding claims, characterized in that to produce at least one structured metallization on a surface side of a subsequent layer, For example, on a surface side of the carrier substrate (2), the layout or the metal areas (3.1) of the structured metallization, for example produced by punching, metal elements or pads (3.2) are provided in a position corresponding to the structured metallization and using the adhesive and bonding material the subsequent one

Layer can be connected.

36. The method according to claim 35, characterized in that the metal elements or pads (3.2) are provided by arranging these elements in a mask or mold 87) and / or by applying these elements in the precise position on an auxiliary carrier or a carrier material (9). .

37. The method according to claim 35 or 36, characterized in that the adhesive or bonding material is applied over the entire surface to the surface area of the adjacent layer (2) to be provided with the structured metallization, and that after bonding, i.e. after setting and / or hardening of the Adhesive or bonding material (5) between the metal areas (3.1) of the structured metallization (3) is removed, for example mechanically, for example: by sandblasting, and / or by laser or plasma treatment.

38. The method according to any one of the preceding claims, characterized in that the adhesive or bonding material is applied to the surface side of the subsequent layer to be provided with the structured metallization in one of the metal areas or pads (3.1) of the structured

Metallization (3) structured according to shape and position and / or applied to the surface side of the provided metal elements (3.2) to be connected to the adjacent layer.

39. Method according to one of the preceding claims, characterized in that the at least one metallization (3, A) consists, at least in some areas, of a layer or foil made of copper or aluminum or of a metallic resistance material.

40. Method according to one of the preceding claims, characterized in that the at least one metallization (3, 4) is made, at least in some areas, of copper and/or of aluminum and/or a metallic alloy, for example of a copper alloy or aluminum alloy, and/or of a metallic composite and/or multilayer material, for example made of an aluminum/copper multilayer material, for example in the form of a metallic foil.

41. The method according to any one of the preceding claims, characterized in that the composite material is after-treated by annealing after the application of the at least one metallization (3, A), in particular to improve the thermal conductivity, for example at a temperature equal to or higher than that of Bonding temperature used to set the adhesive and bonding material.

42. The method according to any one of the preceding claims, characterized in that the adhesive and bonding material is applied to the carrier substrate (2) using masks, in particular shadow masks (18), stencils, screens, by spraying, rolling and / or spincoating.

43. The method according to claim 42, characterized in that the full-surface and/or structured application of the adhesive or bonding material is carried out using at least one mask and/or stencil and/or using a screen printing process.

44. Method according to one of the preceding claims, characterized in that the bonding and/or the aftertreatment or the annealing are carried out under pressure.

45. Method according to one of the preceding claims, characterized in that the mixing of the adhesive or bonding material and/or the bonding is carried out in such a way that the adhesive or bonding layer (5) formed by the adhesive or bonding material is at least in the finished composite material (1) is free of gas and/or vapor bubbles, in particular air bubbles, the volume fraction of such bubbles in the adhesive or

Bond layer (5) based on the total volume of this layer is at most 0.1% by volume.

46. Method according to one of the preceding claims, characterized in that the adhesive or bonding layer (5, 5.1) is also powdery

Contains additives such as carbon, graphite and/or ceramic and/or metallic additives.

47. Method according to one of the preceding claims, characterized in that the nanofiber material is a metal-free or im

Substantially metal-free nanofiber material, in particular a nanofiber material without Ni, Fe and / or Co and / or a chemically and / or thermally pretreated nanofiber material.

48. Method according to one of the preceding claims, characterized in that the total proportion of the nanofiber material and any other components in the plastic matrix of the adhesive or bonding layer (5, 5.1) is selected such that the glass transition temperature of the adhesive or bonding material or the plastic matrix is at least 150 ⁰ C and/or at least 25% compared to the glass transition temperature of the plastic matrix forming Plastic, for example epoxy, is increased, and/or that the total proportion of nanofiber material and any other additives is approximately 25% by weight based on the total mass of the adhesive or bonding layer.

49. Method according to one of the preceding claims, characterized in that the total proportion of nanofiber material and any further additives is selected so that a thickness of the at least one adhesive or bonding layer smaller than 25 μm is possible.

50. Method according to one of the preceding claims, characterized in that the total proportion of nanofiber material and ggs. Further fillers are selected so that the thermal conductivity of the adhesive or bonding layer (5, 5.1) is at least a factor of four, preferably at least a factor of five, greater than the thermal conductivity that the plastic forming the plastic matrix without nanofiber material and also. has further fillers, for example greater than 1 W/mK.

51. Bonding material or adhesive for producing an adhesive or bond connection between two elements, for example between a carrier substrate (2) and a metallization (3, A) ₁ consisting of a plastic matrix containing at least one nanofiber material, characterized in that the proportion of the nanofiber material as well as ggs. Further additives in the plastic matrix are selected such that the adhesive or bonding material is suitable for processing with a layer thickness of less than 25 μm.

52. Bonding material or adhesive claim 51, characterized in that the nanofiber material is a carbon nanofiber material, and / or that the nanofiber material is contained in the adhesive or bonding material in a proportion of 5 to 30 percent by weight, based on the total weight of this material.

53. Bonding material or adhesive according to claim 51 or 52, characterized in that the nanofiber material is formed by nanofibers and / or nanotubes, preferably at least a large part of these nanofibers or nanotubes having a length in the range between approximately 1 μm and 100 μm and a thickness approximately in the range between 1 nm to 300nm or in the range between about 50nm to 150nm or in the range between about 1 nm to 100nm, for example in the range of about 3nm to 75nm.

54. Bonding material or adhesive according to one of the preceding claims, characterized in that the matrix is one based on epoxy or epoxy resin.

55. Bonding material or adhesive according to one of the preceding claims, characterized in that it contains further additives, for example flame-retardant additives, for example halides or boron compounds.

56. Bonding material or adhesive according to one of the preceding claims, characterized in that the plastic material forming the matrix is selected such that it has a temperature resistance of at least 220 ⁰ C in the hardened and / or set state.

57. Bonding material or adhesive according to one of the preceding claims, characterized in that it contains powdery additives such as carbon, graphite,

Contains ceramic and/or metallic additives.

58. Bonding material or adhesive according to one of the preceding claims, characterized in that the nanofiber material is a metal-free or essentially metal-free nanofiber material, in particular a Nanofiber material without Ni, Fe and/or Co and/or a chemically and/or thermally pretreated nanofiber material.

59. Bonding material or adhesive according to one of the preceding claims, characterized in that the total proportion of the nanofiber material and any other components is selected such that the glass transition temperature of the bonding material or adhesive or the plastic matrix is at least 150 ⁰ C and / or at least around 25% compared to the glass transition temperature of the plastic forming the plastic matrix, for example epoxy, and / or that the total proportion of nanofiber material and any other additives is approximately 25% by weight based on the total mass of the adhesive or bonding layer.

60. Bonding material or adhesive according to one of the preceding claims, characterized in that the total proportion of nanofiber material and ggs. Further fillers are selected so that the thermal conductivity of the bonding material or adhesive is at least a factor of five greater than the thermal conductivity that the plastic forming the plastic matrix has, for example greater than 1 VWmK.