JP7499869B2 - Connecting the parts - Google Patents

Description

The present invention relates to a method and a connection element for connecting a first component to a second component, and also to an arrangement of two components connected to each other, particularly in relation to electronic components.

The invention further relates to a method for connecting a first contact surface to a second contact surface and to the use of a connecting element for connecting a first contact surface to a second contact surface, and also to an arrangement of two contact surfaces connected to each other, in particular in relation to electronic components.

There is a need to connect objects together in a wide variety of applications, for example two metal objects or objects made of different materials. This is especially the case in the electronics field. Various methods are known from the prior art for producing such connections. In particular, methods are known for connecting electrical conductors or objects, for example made of copper, by welding, hard soldering, soft soldering, adhesive bonding, screwing, riveting or embossing. In such methods, the connection is made by precisely matching prepared surfaces with respect to one another. The objects to be connected must therefore be clearly and geometrically defined and prepared with respect to their length and the connection position. Furthermore, preparations must be made in advance for making the connection, for example by drilling holes or providing corresponding connection elements. Connection techniques by adhesive bonding, screwing or riveting are processes carried out at room temperature. On the other hand, welding, soft soldering or hard soldering are processes carried out at high temperatures, in which a liquid metal is produced, which fills a volume or interacts metallically with the joint.

Welding has the disadvantage that it involves the application of considerable temperatures, usually up to 1400°C, which can heat the objects to a considerable extent and thus cause fires with flammable materials. It can also cause visual changes to the surfaces of the objects being joined, which can be problematic especially for surfaces that have been pretreated with lacquers, films or coatings. In addition, many materials cannot be welded.

For example, copper hard soldering involves the input of significant thermal energy, which can result in significant heating of the parts involved in the connection (especially to above 400°C). This can lead to the ignition of flammable materials.

Soft soldering, for example of copper, can have the disadvantage that the shear strength of the connection is lower than desired, while soft soldering can lead to demixing of the metals due to changing temperature loads and thus embrittlement of the connection. This can lead to failure of the connection. Furthermore, soft soldering has the disadvantage that the transmission resistance of the connection is much higher than, for example, pure copper. Another disadvantage of soft soldered connections is the low mechanical fatigue strength, which usually only exists up to about 120 °C. The corrosion resistance of such connections in acidic media is also often insufficient.

Particularly in the adhesive bonding of conductive components (e.g. copper components), it is often a disadvantage that the electrical transmission resistance is adversely affected to a considerable extent by the adhesive bond. It is not always possible for a conductive bond to fulfill the mechanical requirements in terms of the mechanical strength of the connection. Furthermore, even if there is sufficient mechanical strength, it usually only exists up to a temperature range of 120°C. This may preclude use in particular in warm or hot environments or with hot media.

In the case of screwing and riveting, the parts must be joined particularly precisely. Furthermore, the holes and structures required for screwing or riveting connections often cause visual damage to the visual and mechanical appearance of the entire construction. Furthermore, from a construction point of view, it is necessary to ensure that the exact position where the connection has to be made is known in advance, which may make the use of parts of no fixed length more complicated or even preclude it. Furthermore, in the case of such connections, residual gaps are usually present between the parts. Moisture can penetrate into the residual gaps by capillary action, which then leads to corrosion. Corrosion can damage the connection. The electrical and thermal transfer resistance of the connection may also increase. Furthermore, the holes for screwing or riveting can cause leaks in the area of the connection. This can make the use of such connections, for example, in containers or pressure systems more difficult, in particular in that additional sealing means are required.

The object of the present invention is therefore to solve or at least alleviate the technical problems considered in relation to the prior art. It is intended to provide a method and a connection element for connecting a first part to a second part, such that a connection that is particularly mechanically stable and has particularly good thermal conductivity is or is formed between the parts in a particularly reliable and simple manner, as well as to provide an arrangement of two parts connected to each other.

The object of the present invention is therefore to solve or at least alleviate the technical problems considered in relation to the prior art. It is intended to provide a method and a connection element for connecting a first part to a second part, such that a connection that is particularly mechanically stable and has particularly good thermal conductivity is or is formed between the parts in a particularly reliable and simple manner, as well as to provide an arrangement of two parts connected to each other.

In particular, it is intended to provide a method for connecting a first contact surface to a second contact surface and to use a connecting element for connecting the first contact surface to the second contact surface, such that a connection that is particularly mechanically stable and has at least one of particularly good electrical and thermal conductivity is or can be formed between the contact surfaces in a particularly reliable and simple manner, and also to provide an arrangement of two contact surfaces connected to one another.

The above-mentioned object is achieved by a method, a connecting element, the use of a connecting element and a device according to the features of the independent patent claims. The dependent claims each indicate advantageous configurations. The features recited individually in the claims can be combined with one another in any technically significant manner and can be supplemented by the explanatory technical content of the present specification recited further variants of the invention.

In accordance with the present invention, a method for connecting a first part to a second part is provided, the method comprising the steps of:
a) providing a connecting element,
the connecting element comprises a number of nanowires on a first connecting surface on a first side of the connecting element and on a second connecting surface on a second side of the connecting element opposite the first side;
the first connecting surface and the second connecting surface being electrically insulated from each other;
b) mating a contact surface of the first part with a first connecting surface of the connecting element;
and c) mating the contact surface of the second part with the second connecting surface of the connecting element.

The first and second components are preferably electronic components, such as, for example, semiconductor components, computer chips, microprocessors, or printed circuit boards. The first or second component, or both, are preferably at least partially thermally conductive. The first or second component, or both, may be wholly or partially electrically conductive or electrically insulating. Electrical insulation between the connection surfaces ensures that the electrically conductive components are not connected to each other in an electrically conductive manner.

Electrical and thermal conductivity in the sense used herein is present in particular in metals (copper, for example) and is also generally referred to as "electrically conductive" or synonymously as "electrically conductive", "thermally conductive" or "thermally conductive". In particular, it is not intended herein to consider materials that are generally considered to be electrically insulating or thermally insulating or both as being electrically conductive or thermally conductive or both. It is intended to consider the first and second connecting surfaces as being electrically insulated from each other if the electrical resistance between the first and second connecting surfaces is measured to be at least 100 KΩ in a four-terminal measurement. This measurement was performed at room temperature, with an air humidity of 20%, at a constant voltage (i.e. not an alternating voltage), with respective electrodes on the first and second connecting surfaces, the electrodes contacting the respective connecting surfaces over an area of ¹ cm2.

The method is not limited to applications in the field of electronics. For example, a component such as a sensor (as a first component) can also be fixed by the method to a wall or a mount (as a second component). Using the method, a connection can be formed between a first component and a second component that is particularly mechanically stable, electrically insulating and preferably thermally conductive. In this way, the method can be employed in all fields where a corresponding connection between two components is required. The method is also not limited to components of a certain size. The method is therefore suitable for applications in the field of electronics, particularly microelectronics, for example, or for connecting components of considerable size at a macroscopic level.

The components can be connected to the connection element via their respective contact surfaces. The contact surfaces are in particular spatially distinct areas of the surface of the respective components. In particular, the contact surfaces are preferably differentiated by the formation of the connection. This means that the contact surfaces are initially not different from the rest of the surface of the components and are differentiated because they are areas formed on the connection only by the formation of the connection. In this case, the contact surfaces are initially only conceptually distinct from the rest of the surface of the components. In the region of the contact surfaces the nanowires of the connection element can come into contact with the respective components.

Preferably, each contact surface is simply a continuous area of the surface of the respective part. Alternatively, each contact surface of the first part or the second part or both can be further divided into a number of separate sub-areas of the surface of the respective part. Thus, the contact surface can be made up of two or more separate portions of the surface of each part. The contact surfaces can be electrically conductive or electrically insulating or thermally conductive or thermally insulating or a combination thereof. By virtue of the electrical insulation between the connecting surfaces, the connection is in each case electrically insulating.

The components are preferably of rigid design or have at least one rigid surface on which the respective contact surface is provided. This means in particular that the components (or at least the contact surface) are preferably not flexible. Rigid components or contact surfaces allow the connection to be formed in a particularly satisfactory manner according to the method. If, for example, one of the components is of flexible design, the connection may break due to the load of the nanowires. However, depending on the exact circumstances, it is also possible to advantageously carry out the method using flexible components or contact surfaces.

In this method, the connection between the first component and the connection element is formed via a number of nanowires.

Nanowires in this specification should be understood to mean any wire-like material body with a size ranging from a few nanometers to a few micrometers. Nanowires may for example have a circular, elliptical or polygonal base. In particular, nanowires may have a hexagonal base. All nanowires involved in a connection are preferably made of the same material. Thanks to the configuration of the connection elements, when the nanowires are made of an electrically conductive material, electrical insulation between the contact surfaces of the components to be connected is also provided. Thus, nanowires can be made of at least one electrically conductive and insulating material.

The nanowires on the first connecting surface are preferably formed from the same material as the nanowires on the second connecting surface. Alternatively, the nanowires on the first connecting surface and the nanowires on the second connecting surface are preferably formed from different materials.

Particularly preferably, at least one of the nanowires on the first connecting surface and the nanowires on the second connecting surface are formed from the respective metal. Even more preferably, the nanowires on the first connecting surface are formed from the material of the contact surface of the first component, or the nanowires on the second connecting surface are formed from the material of the contact surface of the second component, or both.

Depending on the material of the nanowire, the connection may have different properties. In particular, the mechanical strength and thermal conductivity of the connection are influenced by the material of the nanowire. By forming the nanowire from different materials on the two connection surfaces, it is possible to form two connections with different properties. In this way, two parts that would otherwise be impossible or difficult to connect to each other can be connected to each other via the connection element, so that the connection element can be considered as an intermediate between the two parts to be connected.

The nanowires preferably have a length in the range of 100 nm [nanometers] to 100 μm [micrometers], in particular a length in the range of 500 nm to 30 μm. Furthermore, the nanowires preferably have a diameter in the range of 10 nm to 10 μm, in particular a diameter in the range of 30 nm to 2 μm. The expression "diameter" in this specification relates to a circular base, and in the case of bases deviating from this, a similar definition of diameter shall be used. It is particularly preferred that all nanowires used have the same length and the same diameter.

In the method of the invention, the components are indirectly connected to one another via the connecting elements. This has the advantage that it is not necessary to provide nanowires on any of the components. The nanowires only need to be present on the connecting elements. In particular, it is preferred that the nanowires are only provided on the connecting surfaces of the connecting elements and not on the contact surfaces of the components. This makes the method easier to carry out and in particular allows the method to be extended to components where nanowires cannot or are difficult to grow. The nanowires can also be grown locally away from the components. Nevertheless, it is also preferred that instead a respective multiplicity of nanowires is provided on at least one of the contact surfaces of the first component and the contact surface of the second component.

The connecting element is preferably of flexible construction. Alternatively, the connecting element is preferably of rigid construction. The connecting element may be constructed, for example, in the form of a solid small metal plate. In that case, electrical insulation between the connecting surfaces may be achieved by one or more coatings.

The connecting element is preferably made of plastic. For example, the connecting element can be made of a polymer, in particular polycarbonate, PVC, polyester, polyethylene, polyamide, PET or a combination thereof. The connecting element can also be made of ceramic materials, silicon, aluminum oxide, glass, etc. Furthermore, the connecting element can be made of stainless steel, aluminum, non-ferrous metals, etc. The connecting element is also preferably made of a composite material that includes some of the aforementioned materials.

In step a), a connection element is provided having two connection surfaces. Each of the two connection surfaces has a number of nanowires. The first connection surface is provided on a first side of the connection element, and the second connection surface is provided on a second side of the connection element. The first and second sides of the connection element are provided on opposite sides. The first side of the connection element is the side of the connection element that faces the first component after the connection is formed. The second side of the connection element is the side of the connection element that faces the second component after the connection is formed. Thus, after the connection is formed, the contact surfaces of the two components are provided on the two sides of the connection element in a mutually opposing manner, so that the components can be connected using this method. In this case, the distance between the two contact surfaces is caused only by the thickness of the connection element and the space occupied by the nanowires.

The connection element is provided in step a) of the method. On the one hand, "provided" is to be understood in this case to mean that the connection element configured as described is provided as part of the method. It is therefore in particular possible to apply nanowires to the connection surface as part of the method, in particular by means of galvanic growth. On the other hand, however, "provided" also includes the use of a connection element whose connection surface is already provided with nanowires. Thus, for example, it is possible to obtain correspondingly prepared connection elements from a supplier and use them in the method. The obtaining of such prepared connection elements also constitutes providing a connection element in the sense used here.

The nanowires are preferably provided on the connection surfaces such that they are substantially perpendicular (preferably perpendicular) to the respective connection surface. The entirety of the nanowires on the connection surface may in particular be referred to as a lawn of nanowires. However, the nanowires can also be provided on the connection surface in any orientation. It is also possible to further divide the connection surface into a number of (connected or separate) sub-regions, with the nanowires pointing in different directions in the different sub-regions. In this way, in particular particularly stable connections can be achieved which can withstand shear forces particularly satisfactorily. Furthermore, the nanowires can have different configurations at different points of the connection surface, in particular with regard to their length, diameter, material and density (density of nanowires refers to the number of nanowires provided per unit area).

The connecting element can in particular be considered as an intermediate of the connection between the first part and the second part. In particular, the connecting element can be any physical object suitable to be provided between the contact surfaces of the parts in order to connect them together.

The connection surface is in particular a region of the surface of the connection element on each of the sides of the connection element, which is a spatially distinct region. In particular, the connection surface is preferably distinguished by the formation of the connection part. This means that the connection surface is distinguished because it is not initially different from the other parts of the surface of the connection element, and is an area formed on the connection part only by the formation of the connection part. In this case, the connection surface is only conceptually distinct from the other parts of the surface of the connection element before the formation of the connection part. For example, the connection surface of a surface connection element can be distinguished by the formation of a surface connection part for each respective component on a delimited area of the connection element (i.e. on the connection surface).

The connection surfaces are preferably the same size as the corresponding contact surfaces, and particularly preferably have the shape of the corresponding contact surfaces. However, it is possible for the contact surfaces to be larger or smaller than the corresponding connection surfaces, or for the contact surfaces and the corresponding connection surfaces to have different shapes, or both.

Preferably, any connection surface is simply a continuous region of the surface of the connection element. Alternatively, the first connection surface or the second connection surface or both may be further divided into multiple separate sub-regions of the surface of the connection element. Thus, the connection surface may be comprised of two or more separate portions of the surface of the connection element.

In steps b) and c), the contact surface and the connection surface are brought together, i.e. moved towards each other, so that the nanowires on the connection surfaces come into contact with the respective contact surface. In this case, the nanowires connect to the corresponding contact surface, so that a corresponding connection is formed between the component and the connection element.

A connection is formed by connecting each nanowire to the contact surface, in particular by connecting the end of each nanowire facing the respective contact surface. This connection is formed at the atomic level. This process, which proceeds at the atomic level, is similar to the process that occurs during sintering. The connection obtained can be gas-tight or liquid-tight or both, so that in particular corrosion of the connection or of the parts connected to each other or both can be prevented or at least limited in the area of the connection. In particular, the connection formed can be considered to be completely metallic. This method is also called "KlettWelding", which refers to obtaining a connection by heating using a large number of nanowires, i.e. a large number of elongated hair-like structures. The large number of nanowires makes it possible to compensate for unevenness and roughness of the contact surface.

Due to the size of the nanowires in the nanometer range, the surface of the connection (i.e. the area over which forces such as van der Waals forces act at atomic level) is particularly large. The connection can thus have particularly good thermal conductivity or mechanical stability or both. For particularly thermally conductive connections, the nanowires are preferably made of a thermally conductive material. The use of copper is particularly preferred here. The contact surfaces are also preferably made of a thermally conductive material, in particular copper. As further mentioned above, the use of copper is not possible, in particular in the case of welded connections. The large surface of the connection obtained by the method makes it possible to make the thermal conductivity of the connection particularly high. A particularly good thermal conductivity of the connection can, for example, improve the cooling of the components associated with the connection. In particular, the use of copper for the nanowires or the contact surfaces or both for this purpose is preferred.

The aforementioned connections can furthermore be formed in a particularly simple manner and without tools. It is only necessary to connect the parts and bring the connection elements together. The application of heat and pressure can be performed selectively and is not absolutely necessary.

The method steps a) to c) are preferably carried out in the order described, in particular consecutively. In particular, step a) is preferably carried out before steps b) and c) start.

If steps b) and c) are performed in succession, the contact surface of the first part is first brought into alignment with the first connection surface, i.e. the first part and the connection element are first brought into alignment (step b)). Subsequently, the connection element brought into alignment with the first part in step b) is brought into alignment with the second part, such that the contact surface of the second part is brought into alignment with the second connection surface (step c)).

Alternatively, steps b) and c) can be performed simultaneously, overlapping in time or successively. This is possible, for example, if the connecting element is held between two parts and these parts are moved simultaneously from both sides towards the connecting element.

In a preferred embodiment of the method, at least one of steps b) and c) is carried out at room temperature.

The aforementioned connection between the contact surface and the connection surface can also be formed at room temperature. In this case, it is preferred that the two parts are pressed against one another to form the connection. The pressure used here is preferably in the range between 3 MPa and 200 MPa, in particular in the range between 15 MPa and 70 MPa. A pressure of 20 MPa is particularly preferred.

It is also preferred that no heating is performed after steps b) and c) are completed, in order to prevent damage to the components due to the effects of temperature.

In a further preferred embodiment, the method further comprises:
d) heating at least the contact surface to a temperature of at least 90° C.

The contact surfaces are heated to a temperature of at least 90° C. (as a minimum temperature), preferably to a temperature of at least 150° C. (as a minimum temperature). The temperature is preferably 200° C. Heating is preferably carried out to a temperature of up to 270° C., in particular up to 240° C. In this embodiment, it is also preferred that at least one of steps b) and c) is carried out at room temperature. This means that heating is carried out only after the formation of the connection according to steps b) and c). In this way, the formed connection is reinforced by heating.

The heating according to step d) connects the nanowires to the contact surfaces in a particularly satisfactory manner. Therefore, only the contact surfaces need to be heated. In practice, such heating often does not distinguish whether the contact surfaces, the nanowires, the connection elements, part or all of the first part, part or all of the second part, or a combination of these, are heated. This is particularly true when thermally conductive materials are used. For the formation of the connection, it is not necessary, but is also not harmful, to heat (together) elements other than the contact surfaces. The heating according to step d) can therefore be carried out in particular by heating the first part, the second part and the connection elements together, for example in a furnace. However, it is alternatively possible to introduce heat locally into the region of the connection, in particular into the region of the contact surfaces.

To form the connection, the aforementioned minimum temperature must be reached at least once, even for a short time. It is not necessary to maintain the minimum temperature. It is, however, preferable that the temperature at which heating is carried out in step d) is maintained for at least 10 seconds, preferably at least 30 seconds. This makes it possible to form the connection as desired. In principle, a longer temperature maintenance is not detrimental.

Steps b) and c) and also step d) can be carried out in an at least partially overlapping manner. Thus, for example, preheating can be carried out before or during steps b) and c), which can be considered as part of step d). It is also possible to heat the contact surfaces of the first part or the second part or both, respectively, before step d), so that the temperature required for the formation of the connection during the mating operation in step b) or c) is already reached. In particular, in this respect, it is also possible for step d) to start before step b) or c). In this case, step d) is carried out in such a way that the temperature required by step d) is at least temporarily present even after the end of step b) or c).

The method makes it possible to obtain a connection between two parts without reaching temperatures as in the case of, for example, welding or brazing. In the present embodiment, this can be exploited to advantage in that unnecessary heating is not required, for example, this can avoid damage to the parts. Such low temperatures also make it possible to prevent ignition of flammable materials. It is therefore particularly preferred that the temperature of the first part or the second part or both does not exceed 270°C, in particular does not exceed 240°C, at any point during the method.

In a further preferred embodiment of the method, the connection element or the first part or the second part or a combination thereof is subjected to ultrasonic action in at least one of steps b) and c).

In step b), it is preferred that the connection element and the first part are subjected to ultrasonic action. Alternatively or additionally, it is preferred that the connection element and the second part are subjected to ultrasonic action in step c). The ultrasonic action may be performed in such a way that it is completely or almost impossible to distinguish whether the connection element, the first part, the second part, or a combination thereof is acted upon. It is therefore also preferred that in at least one of steps b) and c), the connection element, the first part, and the second part are acted upon by ultrasonic action.

Ultrasound has been shown to contribute to the formation of connections between the nanowires and the contact surface.

In a further preferred embodiment of the method, the first part and the second part are pressed against the connecting element at least during part of the heating with a pressure of at least 3 MPa, in particular at least 15 MPa or at most 200 MPa, in particular at most 70 MPa. This can be done in particular by pressing the two parts towards each other when the connecting element is provided between them.

The pressure used is preferably in the range between 3 MPa and 200 MPa, in particular in the range between 15 MPa and 70 MPa. A pressure of 20 MPa is particularly preferred.

The pressure is preferably above the specified lower limit at least during the period during which the temperature exceeds its specified lower limit. In this regard, the nanowire and the contact surface are thus exposed to both the corresponding pressure and the corresponding temperature for at least this period. This allows a connection to be formed by the action of pressure and temperature.

In a further preferred embodiment of the method, the first connection surface and the second connection surface are configured to face each other.

It is preferable that the first and second connection surfaces are arranged parallel to each other.

In this embodiment, a connecting element can be provided between the two parts to be connected. In this case, the connecting element only has the effect (apart from forming the connection) that the contact surfaces are not directly adjacent to each other but are in particular spaced apart from each other by the material thickness of the connecting element. The orientation of the contact surfaces relative to each other remains unaffected by the connecting element.

Alternatively, it is also possible for example for the first and second connecting surfaces to be provided at different positions on each, in particular on a planar surface, of the connecting element, in which case the first part can be connected to the connecting element at a first of these positions and the second part can be connected to said connecting element at a second of these positions. In a further preferred embodiment of the method, the connecting element provided in step a) comprises a multiplicity of nanowires on a third connecting surface on the first side of the connecting element and on a fourth connecting surface on the second side of the connecting element, respectively, the third and fourth connecting surfaces being electrically conductively connected to one another, and the method further comprises:
b') mating a contact surface of the third part with a third connecting surface of the connecting element;
and c') mating a contact surface of the fourth part with a fourth connecting surface of the connecting element.

In this embodiment, the method is also called the "method of connecting four parts."

Steps b), b'), c) and c') may be performed simultaneously, overlapping in time, or sequentially in any desired order.

In this embodiment, an electrically insulated connection is formed between the first and second parts, and an electrically conductive connection is formed between the third and fourth parts. In this case, there may be multiple pairs of the first and second parts, or multiple pairs of the third and fourth parts, or both.

The first connection surface is preferably electrically conductively isolated from all other connection surfaces. The second connection surface is preferably electrically conductively isolated from all other connection surfaces.

Unless otherwise specified, the above content regarding the first and second parts also applies to the third and fourth parts, and the above content regarding the first and second connecting surfaces also applies to the third and fourth connecting surfaces.

This embodiment can be used, for example, to connect a transistor such as a MOSFET or IGBT as a first component to a heat sink as a second component in an electrically isolated manner, or to connect a microcontroller as a third component to a data line as a fourth component.

The third and fourth connection surfaces are preferably simply continuous regions of the surface of the connection element. Alternatively, the third and/or fourth connection surfaces can be further divided into multiple separate sub-regions of the surface of the connection element. Thus, the connection surfaces can be made up of two or more separate portions of the surface of the connection element. This allows, for example, a microcontroller as the third component to be attached to a multi-pole data line as the fourth component via multiple connections.

The first and third connection surfaces are preferably spaced apart from each other on a first surface of the connection element. The second and fourth connection surfaces are preferably spaced apart from each other on a second surface of the connection element. The first connection surface is preferably arranged opposite the second connection surface. The third connection surface is preferably arranged opposite the fourth connection surface.

In principle, the connection element is preferably made of an electrically insulating material. In this respect, an electrically conductive connection between the third and fourth connection surfaces can be realised by one or more connection lines passing through the connection element in the region of the third and fourth connection surfaces. The connection lines can be made, for example, from copper and can be obtained by lithographic means.

In a further aspect of the invention, a connection element is provided for connecting a first component to a second component. The connection element comprises a number of nanowires on a first connection surface on a first side of the connection element and on a second connection surface on a second side opposite the first side of the connection element. The first connection surface and the second connection surface are electrically insulated from each other.

The particular advantages and design features of the method described above are applicable and transferable to the connecting elements described above, and vice versa.

In a preferred embodiment, the connecting element is of film-like construction.

The film-like configuration means that the thickness of the connection element is very small compared to its extent in other directions. In a preferred embodiment, the thickness of the connection element is at most 5 mm. The thickness of the connection element is preferably in the range between 0.005 mm and 5 mm [millimeters], in particular in the range between 0.01 mm and 1 mm.

Furthermore, the connecting element is preferably configured in a strip. In this embodiment, the first side and the opposite second side of the connecting element are two strip-like surfaces, which have a very large surface area compared to all other surfaces (resulting from the strip's material thickness).

The strip of material can be provided, for example, in the form of a roll. In this case, the nanowires are pre-applied on the strip of material and can be protected, for example, by a protective lacquer. Before using the connection element, the protective lacquer can be removed to expose the nanowires. Each required portion of the strip of material can be separated from the roll for use.

In this embodiment, the connection element can also be referred to as a "connection tape," specifically a "KlettWelding tape" [hook and loop welding tape].

In a further preferred embodiment of the connecting element, in the region between the first and the second connecting surface, the material of the connecting element has a specific electrical resistivity of at least 10 ⁵ Ωm, preferably at least 10 ⁸ Ωm at room temperature.

In this embodiment, at least in the region between the first and second connecting surfaces, the material of the connecting element has a specific electrical resistance at room temperature of at least 10 ⁵ Ωm, in particular at least 10 ⁸ Ωm. However, preferably, outside this region, and particularly preferably over the entire connecting element, the specific electrical resistance is at least 10 ⁵ Ωm, in particular at least 10 ⁸ Ωm.

The specifications given for the specific electrical resistivity of the materials of the connecting elements relate to measurements at constant voltage. When an alternating voltage is applied, different results may be obtained and may depend in particular on the frequency of the alternating voltage.

The stated value of at least 10 ⁵ Ωm, preferably at least 10 ⁸ Ωm, relates to the material of the connection element. Resistivities of various materials are available, for example in tables, in the specialist literature. Reference is made here to specifications of this kind. If the connection element is entirely made of a particular material, the resistivity of the material of the connection element used here is the value specified for this particular material in the specialist literature. This definition means that all effects that are not caused by the material are excluded, such as effects caused by the shape of the connection element. If the connection element is made of different materials, the resistivities of the individual materials can be ascertained from the specialist literature, and the total resistivity of the material of the connection element, i.e. the composition of the material, can be ascertained. If the value of the resistivity of the material used cannot be found in the specialist literature, this value can be ascertained by measurement.

In particular, for the specific electrical resistivity given in this embodiment, it is intended that electrical insulation be considered between the given connection surfaces.

In a further preferred embodiment, the connection element is formed in the region between the first and second connection surfaces from a ceramic material.

In this embodiment, the connection element is formed from a ceramic material at least in the region between the first and second connection surfaces. However, it is preferred that the connection element is also formed from a ceramic material outside this region, particularly preferably over the entire connection element.

In particular, connection elements formed from ceramic materials can have the specified specific electrical resistivity.

In a further preferred embodiment, the connection element is at least partially thermally conductive.

In particular, in this embodiment, the connection formed can have particularly good thermal conductivity.

In a further preferred embodiment, the connection element comprises a number of nanowires on each of a third connection surface on the first side of the connection element and a fourth connection surface on the second side of the connection element, the third connection surface and the fourth connection surface being electrically conductively connected to each other.

As a further aspect of the present invention,
a first part connected to the connecting element by a number of nanowires on a first connecting surface on a first side of the connecting element;
and a second component connected to the connecting element by a multiplicity of nanowires on a second connecting surface on a second side opposite the first side of the connecting element.

The first connection surface and the second connection surface are electrically insulated from each other.

The particular advantages and design features of the method and connecting element described above are applicable and transferable to the present device. The connecting element is preferably configured as described above.

The device is preferably fabricated using the method.

Alternatively, the apparatus may comprise:
A) providing a connecting element,
the connecting element has a first connecting surface on a first side of the connecting element and a second connecting surface on a second side of the connecting element opposite the first side;
the first connecting surface and the second connecting surface being electrically insulated from each other;
B) providing a number of nanowires on a contact surface of the first component and on a contact surface of the second component, respectively;
C) mating a contact surface of the first part with a first connecting surface of the connecting element;
D) mating a contact surface of the second part with a second connecting surface of the connecting element.

As such, such a method is also presented as an aspect of the present invention. The special advantages and design features described above are applicable and transferable to this method, and vice versa.

In this method, the nanowires are not provided on the connecting element, but on the first part and on the second part. This has the advantage that the production of the connecting element is particularly simple.

Further alternatively, the apparatus comprises:
i) providing a connecting element,
the connecting element comprises a number of nanowires on a first connecting surface on a first side of the connecting element;
the connecting element has a second connecting surface on a second side of the connecting element opposite the first side;
the first connecting surface and the second connecting surface being electrically insulated from each other;
ii) providing a number of nanowires on a contact surface of the second component;
iii) mating a contact surface of the first part with a first connecting surface of the connecting element;
and iv) mating a contact surface of the second part with a second connecting surface of the connecting element.

As such, such a method is also presented as an aspect of the present invention. The special advantages and design features described above are applicable and transferable to this method, and vice versa.

In this method, nanowires are provided on the connection element for one of the connections and on the component for the other connection.

Generally, this allows the provision of nanowires on the contact surfaces of the components associated with the connection or on the corresponding connection surfaces. It is thus possible to provide nanowires on both connection surfaces of the connection element (as in the case of the method comprising steps a) to c)), to provide nanowires on the contact surfaces of both components (as in the case of the method comprising steps A) to D)), or to provide nanowires on one of the connection surfaces of the connection element and on the contact surface of the component (as in the case of the method comprising steps i) to iv). In all methods, it is also preferred to provide nanowires both on the connection surface and on the associated contact surface. In this case, a connection is formed between the nanowires.

As a further aspect of the present invention,
An apparatus comprising:
A first part;
Functional elements;
A second part;
A first connection element;
a second connection element;
A device is presented in which a first component is connected to a first connection surface of a first connection element via a number of nanowires, a functional element is connected on a first side to a second connection surface of the first connection element via a number of nanowires and on a second side to the first connection surface of the second connection element via a number of nanowires, a second component is connected to the second connection surface of the second connection element via a number of nanowires, the first and second connection surfaces of the first connection element are electrically insulated from each other, and the first and second connection surfaces of the second connection element are electrically insulated from each other.

The method, the connecting elements, and the particular advantages and design features of the device described above are applicable and transferable to the present device. The device is preferably made by using the method twice. Two connecting elements are preferably formed as described.

The functional element may in particular be part of a functional layer of the electronic device. The functional element preferably performs one or more of the following functions: heat dissipation, vibration damping, mechanical stabilization. The functional element may for example be formed from a textile. The functional element may also be part of the housing.

As a further aspect of the present invention, a method of connecting a first interface to a second interface is provided, the method comprising the steps of:
a) providing a connecting element comprising a multitude of nanowires on a first connecting surface and on a second connecting surface,
a step, the first connecting surface and the second connecting surface being provided on the same side of the connecting element;
b) mating the first contact surface with a first connecting surface of a connecting element;
and c) mating the second contact surface with a second connecting surface of the connecting element.

The method makes it possible to form a connection between two contact surfaces. The first and second contact surfaces can be on the same component or on different components. The component or the two components can in particular be one or two electronic components, respectively, such as, for example, a semiconductor component, a computer chip, a microprocessor or a printed circuit board. The component or components are preferably at least partially electrically conductive or thermally conductive or both.

Electrical and thermal conductivity as used herein are present especially in metals (e.g., copper), and are also commonly referred to as "electrically conductive" or synonymously as "electrically conductive," "thermally conductive," or "thermally conductive." In particular, it is not intended herein that materials that are commonly considered to be electrically insulating or thermally insulating, or both, be considered to be electrically conductive or thermally conductive, or both.

However, the method is not limited to applications in the field of electronics. With the method, a connection can be formed between a first contact surface and a second contact surface that is particularly mechanically stable and electrically or thermally conductive or both. The method can thus be employed in all fields where a connection between two contact surfaces having one or more of these properties is required. The method is also not limited to components of a certain size. The method is therefore suitable for applications in the field of (micro)electronics, for example, or for connecting contact surfaces of considerable size on a macroscopic level.

The contact surfaces are in particular spatially distinct regions of the surface of the component. In particular, the contact surfaces are preferably differentiated by the formation of a connection. This means that each contact surface is initially not different from the rest of the surface of the component (except for the respective mating contact surface, as described below) and each contact surface is differentiated because it is an area formed on the connection only by the formation of the connection. In this case, the contact surfaces are conceptually (i.e. without spatial differentiation) differentiated from the rest of the surface of the component. For example, the contact surface of a surface electrical conductor can be differentiated by the formation of a surface connection to a second electrical conductor on a delimited area of the surface conductor (i.e. on the contact surface). Each contact surface is preferably simply a continuous area of the surface of the same component or of each respective surface of each component. Alternatively, the first contact surface or the second contact surface or both can be further divided into a plurality of separate sub-areas of the surface of the same component or of each respective surface of each component or both. Thus, the contact surface can be composed of two or more separate portions of the surface.

The two contact surfaces to be connected can be distinguished from each other even before the formation of the connection. In the case where a connection surface provided with nanowires is connected to a contact surface, the arbitrary conceptual subdivision of one contact surface into two contact surfaces cannot be understood as a connection of two contact surfaces. The two contact surfaces connected by the method are functionally distinguishable from each other. Thus, in the case where a contact surface consisting of a number of small areas is brought into contact with the nanowires of the connection surface, it is also not possible to interpret this as a connection of two contact surfaces if the individual small areas of the contact surface all perform the same function. In particular, an electrical contact is considered as a function. The two contact surfaces to be connected by the method are preferably electrically insulated from each other. By forming a connection with a connection element, it is possible to create an electrical connection between the contact surfaces. The contact surfaces can be electrically conductive or electrically insulating or thermally conductive or thermally insulating or a combination thereof. It is preferable that the contact surfaces are at least one of electrically conductive and thermally conductive, so that at least one of electrically conductive and thermally conductive connections can be formed.

The contact surfaces are preferably of rigid design. This means that the surface of the respective component on which the contact surface is located is of rigid construction, at least in the region of the contact surface. The contact surfaces are therefore not flexible. Between the rigid contact surfaces, connections can be formed in a particularly satisfactory manner according to the method. If, for example, one of the contact surfaces is of flexible design, the connection may break due to the load of the nanowires. However, depending on the exact circumstances, it is also possible to advantageously carry out the method using flexible contact surfaces.

In this method, the connection between the first contact surface and the second contact surface is formed via a number of nanowires.

A nanowire in this specification should be understood to mean any wire-shaped body of material with a size ranging from a few nanometers to a few micrometers. The nanowire may have, for example, a circular, elliptical or polygonal base. In particular, the nanowire may have a hexagonal base. It is preferred that all nanowires involved in a connection are made of the same material. It is particularly preferred that the nanowires are made of at least one of an electrically and thermally conductive material.

The nanowires on the first connecting surface are preferably formed from the same material as the nanowires on the second connecting surface. Alternatively, the nanowires on the first connecting surface and the nanowires on the second connecting surface are preferably formed from different materials.

Particularly preferably, at least one of the nanowires on the first connecting surface and the nanowires on the second connecting surface are formed from the respective metal. Even more preferably, the nanowires on the first connecting surface are formed from the material of the first contact surface, or the nanowires on the second connecting surface are formed from the material of the second contact surface, or both.

Depending on the material of the nanowire, the connection may have different properties. In particular, the mechanical strength and/or electrical and thermal conductivity of the connection are influenced by the material of the nanowire. By forming the nanowire from different materials on the two connection surfaces, it is possible to form two connections with different properties. In this way, two contact surfaces that would otherwise be impossible or difficult to connect to each other can be connected to each other via the connection element, so that the connection element can be considered as an intermediate between the two contact surfaces to be connected.

The nanowires preferably have a length in the range of 100 nm [nanometers] to 100 μm [micrometers], in particular a length in the range of 500 nm to 60 μm. Furthermore, the nanowires preferably have a diameter in the range of 10 nm to 10 μm, in particular a diameter in the range of 30 nm to 2 μm. The expression "diameter" in this specification relates to a circular base, and in the case of bases deviating from this, a similar definition of diameter shall be used. It is particularly preferred that all nanowires used have the same length and the same diameter.

In the method of the invention, the contact surfaces are indirectly connected to one another via a connecting element. This has the advantage that no nanowires need to be provided on any of the contact surfaces. The nanowires only need to be present on the connecting element. This makes the method easier to carry out and in particular allows the method to be extended to contact surfaces where nanowires cannot or are difficult to grow. The nanowires can also be grown locally away from the contact surfaces. Nevertheless, it is also preferred that instead a respective multiplicity of nanowires is provided on at least one of the first and second contact surfaces.

The connecting element is preferably of flexible construction. Alternatively, the connecting element is preferably of rigid construction. The connecting element may be, for example, in the form of a solid small metal plate.

The connecting element is preferably made of plastic. For example, the connecting element can be made of a polymer, in particular polycarbonate, PVC, polyester, polyethylene, polyamide, PET or a combination thereof. The connecting element can also be made of ceramic materials, silicon, aluminum oxide, glass, etc. Furthermore, the connecting element can be made of stainless steel, aluminum, non-ferrous metals, etc. The connecting element is also preferably made of a composite material that includes some of the aforementioned materials.

In step a), a connection element is provided having two connection surfaces. The two connection surfaces each have a number of nanowires. The first and second connection surfaces are provided on the same side of the connection element. This means that the two connection surfaces are adjacent to each other. The connection surfaces can be in contact with each other, i.e. merged with each other. Alternatively, the connection surfaces can be formed apart from each other. In this way, the method makes it possible in particular to connect contact surfaces that are adjacent to each other. The contact surfaces can be in contact with each other. However, the two contact surfaces are separated from each other, such that it is also possible to separate the two contact surfaces before the formation of the connection. The contact surfaces are preferably formed apart from each other. In this case, the contact surfaces are separated from each other by being spatially separated and can be distinguished from each other in this respect.

The connection element is provided in step a) of the method. On the one hand, "provided" is to be understood in this case to mean that the connection element configured as described is provided as part of the method. It is therefore in particular possible to apply nanowires to the connection surface as part of the method, in particular by means of galvanic growth. On the other hand, however, "provided" also includes the use of a connection element whose connection surface is already provided with nanowires. Thus, for example, it is possible to obtain correspondingly prepared connection elements from a supplier and use them in the method. The obtaining of such prepared connection elements also constitutes providing a connection element in the sense used here.

The nanowires are preferably provided on the connection surfaces such that they are substantially perpendicular (preferably perpendicular) to the respective connection surface. The entirety of the nanowires on the connection surface may in particular be referred to as a lawn of nanowires. However, the nanowires can also be provided on the connection surface in any orientation. It is also possible to further divide the connection surface into a number of (connected or separate) sub-regions, with the nanowires pointing in different directions in the different sub-regions. In this way, in particular particularly stable connections can be achieved which can withstand shear forces particularly satisfactorily. Furthermore, the nanowires can have different configurations at different points of the connection surface, in particular with regard to their length, diameter, material and density (density of nanowires refers to the number of nanowires provided per unit area).

The connecting element can in particular be considered as an intermediate of the connection between a first part and a second part. In particular, as a connecting element any physical object suitable for covering two contact surfaces in order to connect the parts together is considered.

The connection surface is in particular a region of the surface of the connection element on each of the sides of the connection element, which is a spatially distinct region. In particular, the connection surface is preferably differentiated by the formation of the connection part. This means that the connection surface is differentiated because it is not initially different from the rest of the surface of the connection element and is an area formed on the connection part only by the formation of the connection part. In this case, the connection surface is only conceptually distinct from the rest of the surface of the connection element before the formation of the connection part. For example, the connection surface of a surface connection element can be differentiated by the formation of a surface connection part for each respective contact surface on a delimited area of the connection element (i.e. on the connection surface).

The connection surfaces are preferably the same size as the corresponding contact surfaces, and particularly preferably have the shape of the corresponding contact surfaces. However, it is possible for the contact surfaces to be larger or smaller than the corresponding connection surfaces, or for the contact surfaces and the corresponding connection surfaces to have different shapes, or both.

The connection surface is preferably in each case simply a continuous region of the surface of the connection element. Alternatively, the first connection surface or the second connection surface or both can be further divided into a number of separate sub-regions of the surface of the connection element. Thus, the connection surface can be made up of two or more separate parts of the surface of the connection element.

In steps b) and c), the contact surface and the connection surface are brought together, i.e. moved towards each other, so that the nanowires on the connection surfaces come into contact with the respective contact surface. In this case, the nanowires connect to the corresponding contact surface, so that a corresponding connection is formed between the component and the connection element.

A connection is formed by connecting each nanowire to the contact surface, in particular by connecting the end of each nanowire facing the respective contact surface. This connection is formed at the atomic level. This process, which proceeds at the atomic level, is similar to the process that occurs during sintering. The connection obtained can be gas-tight or liquid-tight or both, so that in particular corrosion of the connection or of the parts connected to each other or both can be prevented or at least limited in the area of the connection. In particular, the connection formed can be considered to be completely metallic. This method is also called "KlettWelding", which refers to obtaining a connection by heating using a large number of nanowires, i.e. a large number of elongated hair-like structures. The large number of nanowires makes it possible to compensate for unevenness and roughness of the contact surface.

Due to the size of the nanowires in the nanometer range, the surface of the connection (i.e. the area over which forces such as van der Waals forces act at atomic level) is particularly large. The connection can thus have particularly good electrical and/or thermal conductivity and/or mechanical stability. In particular for electrically and/or thermally conductive connections, the nanowires are preferably made of an electrically and/or thermally conductive material. The use of copper is particularly preferred here. The contact surface is also preferably made of an electrically and/or thermally conductive material, in particular of copper. As further mentioned above, the use of copper is not possible, in particular in the case of welded connections. The large surface of the connection obtained by the method allows the electrical and/or thermal conductivity of the connection to be particularly high. The particularly good thermal conductivity of the connection can, for example, improve the cooling of the components associated with the connection. In particular, the use of copper for the nanowires or the contact surface or both is preferred for this purpose.

The aforementioned connection can furthermore be formed in a particularly simple manner and without tools. It is only necessary to connect the contact surfaces and bring the connection elements together. The application of heat and pressure can be carried out selectively and is not absolutely necessary.

The method steps a) to c) are preferably carried out in the order described, in particular consecutively. In particular, step a) is preferably carried out before steps b) and c) start.

If steps b) and c) are performed in succession, the first contact surface and the first connecting surface are first brought together (step b)). Then the connecting element, together with the part on which the first contact surface is located, is brought together with the second contact surface (step c)). This is particularly possible if the first contact surface and the second contact surface are provided on different parts.

Alternatively, steps b) and c) can be performed simultaneously, overlapping in time or successively. This is particularly possible if the connection element moves simultaneously towards the two contact surfaces. This is particularly possible if the two contact surfaces are adjacent to each other, in particular if both contact surfaces are formed on the same part.

Preferably, the first and second connection surfaces are electrically conductively connected to each other. Thus, the first and second parts can be electrically conductively connected to each other. Alternatively, the first and second connection surfaces are preferably electrically insulated from each other. Thus, the first and second parts can be mechanically connected to each other without forming an electrically conductive connection. It is also possible to combine these two embodiments. In this way, the connection element can further comprise a multiplicity of nanowires on the third and fourth connection surfaces, the third and fourth connection surfaces being provided on the same side of the connection element. This may be the side on which the first and second connection surfaces are provided. Alternatively, the first and second connection surfaces may be provided on different sides of the connection element from the third and fourth connection surfaces. This method comprises:
b') mating the third contact surface with a third connecting surface of the connecting element;
c') mating the fourth contact surface with a fourth connecting surface of the connecting element.

In this embodiment, the method is also called "method of connecting four contact surfaces".

Steps b), b'), c) and c') may be performed simultaneously, overlapping in time, or sequentially in any desired order.

The above also applies to the third and fourth connection surfaces.

The four connection surfaces can be connected to each other in any combination, either electrically conductive or electrically insulated. For example, the third connection surface and the fourth connection surface can be connected to each other in an electrically conductive manner, and all other pairs of connection surfaces can be electrically insulated from each other. As a further example, the first connection surface and the second connection surface can be connected to each other in an electrically conductive manner, the third connection surface and the fourth connection surface can be connected to each other in an electrically conductive manner, and all other pairs of connection surfaces can be electrically insulated from each other. It is also possible for all connection surfaces to be connected to each other in an electrically conductive manner. It is also possible for all connection surfaces to be electrically insulated from each other.

In a preferred embodiment of the method, in step a), the connection element is formed by being separated from the initial body.

The nanowires can be grown on a substrate. This substrate can serve as an initial body from which the connection elements are cut off. The initial body preferably has a number of nanowires in separate areas. The initial body can have, for example, one or more strip-shaped parts with nanowires. Such strips are separated from each other by strips without nanowires. The connection elements can be produced, for example, by cutting out a part of the initial body. The cut-off part forming the connection element preferably has a width such that the connection element has a strip with nanowires in the middle and strips without nanowires on each side. The connection element can also have several strips with nanowires. The length of the parts can be selected as required.

Forming the connection element from the initial body allows step a) to be carried out in a particularly simple and flexible manner.

In a further preferred embodiment of the method, at least one of steps b) and c) is carried out at room temperature.

The aforementioned connection between the contact surface and the connecting surface can also be formed at room temperature. In this case, it is preferred that the connecting element is pressed against the contact surface to form the connection. The pressure used here is preferably in the range between 3 MPa and 200 MPa, in particular in the range between 15 MPa and 70 MPa. A pressure of 20 MPa is particularly preferred.

It is also preferred that no heating is performed after steps b) and c) are completed, in order to prevent damage to the components due to the effects of temperature.

In a further preferred embodiment, the method further comprises:
d) heating at least the contact surface to a temperature of at least 150°C.

The contact surfaces are heated to a temperature of at least 150°C (as a minimum temperature), preferably to a temperature of at least 170°C (as a minimum temperature). Preferably, the temperature is 200°C. Preferably, heating is performed up to a temperature of up to 270°C, in particular up to 240°C. In this embodiment, it is also preferred that at least one of steps b) and c) is performed at room temperature. This means that heating is performed only after the formation of the connection according to steps b) and c). In this way, the formed connection is reinforced by heating.

The heating according to step d) connects the nanowires to the contact surfaces in a particularly satisfactory manner. Therefore, only the contact surfaces need to be heated. In practice, such heating often does not distinguish whether the contact surfaces, the nanowires, the connection element, part or the whole of one or two components, or a combination of these, are heated. This is particularly true when thermally conductive materials are used. For the formation of the connection, it is not necessary, but is also not harmful, to heat (together) elements other than the contact surfaces. The heating according to step d) can therefore be carried out in particular by heating one or two components and the connection element together, for example in a furnace. However, it is alternatively possible to introduce heat locally into the region of the connection, in particular into the region of the contact surfaces.

To form the connection, the aforementioned minimum temperature must be reached at least once, even for a short time. It is not necessary to maintain the minimum temperature. It is, however, preferable that the temperature at which heating is carried out in step d) is maintained for at least 2 seconds, preferably at least 30 seconds. This makes it possible to form the connection as desired. In principle, a longer temperature maintenance is not detrimental.

Steps b) and c) and also step d) can be carried out in an at least partially overlapping manner. Thus, for example, preheating can be carried out before or during steps b) and c), which can be considered as part of step d). It is also possible to heat the contact surfaces of the first part or the second part or both, respectively, before step d), so that the temperature required for the formation of the connection during the mating operation in step b) or c) is reached in advance. In particular, in this respect, it is also possible for step d) to begin before step b) or c). In this case, step d) is carried out in such a way that the temperature required by step d) is at least temporarily present even after the end of step b) or c).

The method makes it possible to obtain a connection between the two contact surfaces without reaching temperatures as in the case of, for example, welding or brazing. This can be exploited in the present embodiment in that it avoids unnecessary heating, for example to avoid damage to the components involved. Such low temperatures also prevent ignition of flammable materials. It is therefore particularly preferred that the temperature of the first or second contact surface or both does not exceed 270°C, in particular 240°C, at any point during the method.

In a further preferred embodiment of the method, the connection element is pressed against at least one of the first and second contact surfaces at a pressure of at least 3 MPa, in particular at least 15 MPa or at most 200 MPa, in particular at most 70 MPa, at least during part of the heating period. This can in particular be done by pressing the connection element against one or two parts.

The pressure used is preferably in the range between 3 MPa and 200 MPa, in particular in the range between 15 MPa and 70 MPa. A pressure of 20 MPa is particularly preferred.

The pressure is preferably above the specified lower limit at least during the period during which the temperature exceeds its specified lower limit. In this regard, the nanowire and the contact surface are thus exposed to both the corresponding pressure and the corresponding temperature for at least this period. This allows a connection to be formed by the action of pressure and temperature.

A further aspect of the invention provides for the use of a connecting element to connect a first contact surface to a second contact surface. The connecting element has a multiplicity of nanowires on the first connecting surface and on the second connecting surface, respectively. The first connecting surface and the second connecting surface are provided on the same side of the connecting element.

The above-mentioned special advantages and design features of the present method are applicable and transferable to this use, and vice versa.

The connecting element is preferably formed to be at least one of electrically conductive and thermally conductive. This allows the contact surfaces to be connected to each other in at least one of an electrically conductive and thermally conductive manner. Alternatively, the first connecting surface and the second connecting surface are preferably electrically insulated from each other.

It is intended that the first and second connecting surfaces are considered to be electrically insulated from each other if the electrical resistance between them is measured to be at least 100 KΩ in a four-terminal measurement, the measurement being performed at room temperature, with an air humidity of 20%, at a constant voltage (i.e., not an alternating voltage), with respective electrodes on the first and second connecting surfaces, the electrodes contacting the respective connecting surfaces over an area of 1 ^cm2 .

If the connection surfaces are electrically insulated from one another, it is possible to form a connection which is electrically insulated between the contact surfaces but which is nevertheless mechanically stable and optionally also thermally conductive. Preferably, in the region between the first and second connection surfaces, the material of the connection element has a specific electrical resistivity of at least 10 ⁵ Ωm, preferably at least 10 ⁸ Ωm, at room temperature.

The specifications given for the specific electrical resistivity of the materials of the connecting elements relate to measurements at constant voltage. When an alternating voltage is applied, different results may be obtained and may depend in particular on the frequency of the alternating voltage.

The stated value of at least 10 ⁵ Ωm, preferably at least 10 ⁸ Ωm, relates to the material of the connection element. Resistivities of various materials are available, for example in tables, in the specialist literature. Reference is made here to specifications of this kind. If the connection element is entirely made of a particular material, the resistivity of the material of the connection element used here is the value specified for this particular material in the specialist literature. This definition means that all effects that are not caused by the material are excluded, such as effects caused by the shape of the connection element. If the connection element is made of different materials, the resistivities of the individual materials can be ascertained from the specialist literature, and the total resistivity of the material of the connection element, i.e. the composition of the material, can be ascertained. If the value of the resistivity of the material used cannot be found in the specialist literature, this value can be ascertained by measurement.

In a preferred embodiment of the use, the first contact surface is provided on a first region of the part and the second contact surface is provided on a second region of the part.

In this embodiment, both contact surfaces are formed on the same component. However, the component is further divided into at least two different regions. The individual regions are distinguishable from one another in terms of structural features. Preferably, the individual regions are also distinguishable from one another in terms of functionality. In particular, the individual regions can be zones into which the electronic component is further divided to facilitate construction and assembly.

In a preferred embodiment of the use, the first connection surface is spaced apart from the second connection surface.

The connection surfaces can be distinguished only conceptually by the formation of a connection. In this case, in the present embodiment, a connection can be present between the connection surfaces that are provided apart from one another. In particular, nanowires can be provided between the connection surfaces that are distinguished as described. This can promote the growth of nanowires, since no measures need to be taken to suppress the growth of nanowires between the connection surfaces. It also makes it possible to greatly facilitate the positioning of the connection elements, since the connection surfaces and the contact surfaces do not need to be overlapped in a precisely matching manner. Instead, each connection surface is formed exactly where it is required to contact the respective contact surface. Furthermore, the connection elements do not need to be specially made for a particular application. Rather, the connection elements can be used flexibly for a wide variety of applications. The nanowires between the connection surfaces can be left unused or can be connected to surface areas outside the contact surfaces.

In a further preferred embodiment of the use, the first contact surface and the second contact surface are connected to each other by a connecting element in an electrically conductive manner or in a thermally conductive manner or in a mechanical manner or in a combination thereof.

In this embodiment, in particular when the nanowires are made of a material that has electrical conductivity or thermal conductivity or mechanical stability or a combination thereof, a connection can be made between the contact surfaces that has an electrically conductive, thermally conductive or mechanical aspect or a combination thereof. The first and second contact surfaces are preferably connected to each other in an electrically conductive or thermally conductive manner or both. The electrically and/or thermally conductive connection between the connecting surfaces can be made by the material of the connecting element. In this regard, it is sufficient that the surface of the connecting element on which the nanowires are provided is electrically and/or thermally conductive.

The latter applies in particular to preferred embodiments of the use in which the nanowires are connected to the connection element by a layer, forming a layer all the way between the first and second connection surfaces.

The layer is preferably used for the galvanic growth of the nanowires. The layer is preferably made of the material of the nanowires. In this way, the substrate can be coated with the material of the nanowires, whereby a layer is obtained. The nanowires are then grown on the layer, which can be delimited by the growth of the nanowires. If the layer is structured before the growth of the nanowires by means of an intermediate lithographic step, it is possible to locally delimit the growth of the nanowires. In this way, an initial body can be obtained in which the nanowires are arranged in the form of strips, etc.

In further preferred embodiments of the use, the layer is thermally conductive, electrically conductive, configured to form a mechanical connection, or a combination thereof.

In particular, with this type of layer, the contact surfaces can be connected to each other in a thermally conductive manner, an electrically conductive manner, a mechanical manner, or a combination thereof. The layer is preferably electrically conductive or thermally conductive or both. Furthermore, if the nanowires are electrically conductive or thermally conductive or both, connections can be made between the contact surfaces that are electrically and/or thermally conductive.

In a further preferred embodiment of the use, the connecting element is of film-like configuration.

The film-like configuration means that the thickness of the connection element is very small compared to its extent in other directions. In a preferred embodiment, the thickness of the connection element is at most 5 mm. The thickness of the connection element is preferably in the range between 0.005 mm and 5 mm [millimeters], in particular in the range between 0.01 mm and 1 mm.

In particular, it is preferable that the film-like connecting element has a flexible configuration.

Furthermore, the connection element is preferably of strip-like configuration. In this embodiment, the connection surface is provided on one of the two surfaces of the strip, which has a very large surface area compared to all the other surfaces (resulting from the material thickness of the strip).

The strip of material can be provided, for example, in the form of a roll. In this case, the nanowires are pre-applied on the strip of material and can be protected, for example, by a protective lacquer. Before using the connection element, the protective lacquer can be removed to expose the nanowires. Each required portion of the strip of material can be separated from the roll for use.

In this embodiment, the connection element can also be referred to as a "connection tape," specifically a "KlettWelding tape" [hook and loop welding tape].

According to a further aspect of the present invention, there is provided a device having a connecting element and a part, the device comprising:
a first contact surface connected to the first connection surface of the connection element by a number of nanowires;
a second contact surface connected to the second connecting surface of the connecting element by a number of nanowires;
The first connecting surface and the second connecting surface are provided on the same side of the connecting element.

The above-mentioned special advantages and design features of the present method and use of the present connection element are applicable and transferable to the present device.

The invention and the technical field are explained in more detail below on the basis of the drawings, which show particularly preferred exemplary embodiments, to which the invention is not, however, limited. It should be noted in particular that the drawings, and in particular the illustrated size ratios, are only schematic.

1 shows a schematic diagram of a method according to the invention for connecting two components; 2 shows a schematic diagram of an apparatus according to the invention of two components connected to each other by the method of FIG. 1; 1 shows a schematic diagram of a further device according to the invention; 1 shows a schematic diagram of a further device according to the invention; 1 shows a schematic diagram of a method according to the invention for connecting two contact surfaces; 6 shows a schematic side view of a first device according to the invention having parts with two contact surfaces connected to each other by the method of FIG. 5 . 7 shows a schematic view of the connection element of FIG. 6 from below. 8 shows a schematic view from below of an initial body from which the connecting elements of FIGS. 6 and 7 are obtained; 4 shows a schematic view from below of a second embodiment of a connecting element; 4 shows a schematic view from below of a third embodiment of a connecting element; 6 shows a schematic side view of a further device according to the invention having parts with two contact surfaces connected to each other by the method of FIG. 5 .

Figure 1 shows a method for connecting a first part 2 to a second part 3. The reference numbers used refer to figure 2. This method comprises the steps of:
a) providing a connecting element 6,
The connecting element 6 comprises a multiplicity of nanowires 1 on a first connecting surface 7 on a first side 10 of the connecting element 6 and on a second connecting surface 8 on a second side 11 of the connecting element 6 opposite the first side 10,
the first connecting surface 7 and the second connecting surface 8 being electrically insulated from each other;
b) bringing the contact surface 4 of the first part 2 and the first connecting surface 7 of the connecting element 6 together;
c) bringing the contact surface 5 of the second part 3 and the second connecting surface 8 of the connecting element 6 together.

At least one of steps b) and c) is preferably carried out at room temperature. The method may further comprise the following optional steps, which are indicated in dashed boxes in FIG.
d) heating at least each contact surface 4, 5 to a temperature of at least 150° C.

Figure 2 shows a device 9 obtained using the method of Figure 1. The device 9 comprises a first part 2 connected to the connection element 6 by a number of nanowires 1 on a first connection surface 7 on a first side 10 of the connection element 6. The device 9 further comprises a second part 3 connected to the connection element 6 by a number of nanowires 1 on a second connection surface 8 on a second side 11 opposite to the first side 10 of the connection element 6. To this end, the first part 2 and the second part 3 have respective contact surfaces 4, 5.

The first connecting surface 7 and the second connecting surface 8 are electrically insulated from each other. For this purpose, the connecting element 6 is formed from a ceramic material at least in the region between the first connecting surface 7 and the second connecting surface 8. As a result, at least in this region, the specific electrical resistance of the connecting element 6 is at least 10 ¹⁰ Ωm. The connecting element 6 is of film-like construction. The thickness of the connecting element 6 is at most 5 mm. The thickness of the connecting element 6 can be specified as the vertical extent of the connecting element 6 in FIG. 2.

Figure 3 shows a device 12 comprising a first part 2, a functional element 13, a second part 3, a first connecting element 6 and a second connecting element 14. The first part 2 is connected to a first connecting surface 7 of the first connecting element 6 via a number of nanowires 1. The functional element 13 is connected on a first side to a second connecting surface 8 of the first connecting element 6 via a number of nanowires 1 and on a second side to a first connecting surface 7 of the second connecting element 14 via a number of nanowires 1. The second part 3 is connected to a second connecting surface 8 of the second connecting element 14 via a number of nanowires 1. The connecting surfaces 7, 8 of the connecting elements 6, 14 are electrically insulated from each other, respectively. The device 12 shown in Figure 3 can be produced by using the method of Figure 1 twice.

Figure 4 shows a device 15 comprising a first part 2, a second part 3, a third part 16 and a fourth part 17. The first part 2 is connected to the connection element 6 by a number of nanowires 1 on a first connection surface 7 of the first side 10 of the connection element 6. The second part 3 is connected to the connection element 6 by a number of nanowires 1 on a second connection surface 8 of the second side 11 opposite the first side 10 of the connection element 6. The first connection surface 7 and the second connection surface 8 are electrically insulated from each other. The third part 16 is connected to the connection element 6 by a number of nanowires 1 on a third connection surface 20 of the first side 10 of the connection element 6. The fourth part 17 is connected to the connection element 6 by a number of nanowires 1 on a fourth connection surface 21 of the second side 11 of the connection element 6. The third connection surface 20 and the fourth connection surface 21 are electrically connected to each other in an electrically conductive manner. The respective contact surfaces 4, 5, 18, 19 of the parts 2, 3, 16, 17 are also shown.

Figure 5 shows a method for connecting the first contact surface 102 and the second contact surface 103. The reference numbers used relate to figure 6. This method comprises the steps of:
a) providing a connecting element 106 comprising a number of nanowires 101 on a first connecting surface 107 and a second connecting surface 108,
a step, the first connecting surface 107 and the second connecting surface 108 being provided on the same side of the connecting element 106;
b) mating the first contact surface 102 with a first connecting surface 107 of a connecting element 106;
c) mating the second contact surface 103 with the second connecting surface 108 of the connecting element 106.

In step a), the connection element 106 is formed by being cut away from the initial body 112 shown in FIG. 8.

At least one of steps b) and c) is preferably carried out at room temperature. The method may further comprise the following optional steps, which are indicated in dashed boxes in FIG.
d) heating at least each contact surface 102, 103 to a temperature of at least 150° C.

Figure 6 shows a device 109 with a connecting element 106 and a part 110. The part 110 has a first contact surface 102 and a second contact surface 103. The first contact surface 102 is connected to a first connecting surface 107 of the connecting element 106 by a number of nanowires 101. The second contact surface 103 is connected to a second connecting surface 108 of the connecting element 106 by a number of nanowires 101. The first connecting surface 107 and the second connecting surface 108 are provided on the same side of the connecting element 106. In the example shown in Figure 6, this is the downward-facing side of the connecting element 106.

The first contact surface 102 is provided in a first region 104 of the part 110. The second contact surface 103 is provided in a second region 105 of the part 110.

The connection surfaces 107 and 108 are spaced apart from each other.

The nanowire 101 is connected to the connection element 106 by a layer 111. The layer 111 is formed all the way between the first connection surface 107 and the second connection surface 108.

Layer 111 is electrically and thermally conductive. Nanowire 101 is formed from an electrically and thermally conductive material, such that contact surfaces 102, 103 are connected to each other in an electrically and thermally conductive manner.

Figure 7 shows a bottom view of the connection element 106 of Figure 6 that can be used in the method of Figure 5. Layer 111 is visible. Figure 7 shows the situation before the connection is made, so that the connection surfaces are not yet differentiated.

8 shows an initial body 112 with a number of strips of the layer 111. These strips with nanowires 101 are separated from each other by strips without nanowires 101. The dashed lines show how the connection element 106 is obtained by cutting out from the initial body 112, which is preferably in the form of a film. The extent of the connection element 106 along the strip of the layer 111 can be selected according to the requirements. The connection element 106 can also be formed by using a number of strips of the layer 111. A number of connection elements 106 can be cut out from the initial body 112. The connection element 106 depicted in dashed lines is the first connection element cut out at one corner as illustrated. Alternatively, it is possible to use, for example, the entire initial body 112 as the connection element 106. It is also not necessary that the strips of the layer 111 are arranged regularly as in the illustrated embodiment. Irregular patterns are also possible, with variations in the width of the bands, the spacing between adjacent bands, the length of the bands (from right to left in FIG. 8), the orientation of the bands, or any combination of these.

Correspondingly, Figures 9 and 10 show two embodiments of the connection element 6 with different arrangements of the layers 111.

The connecting element 106 in FIG. 9 has strips of layers 111 with a continuously decreasing width. This connecting element 6 can be used in particular to connect a large contact surface (on the left side of the connecting element 106) to a smaller contact surface (on the right side).

The connecting element 6 in FIG. 10 has four strips of layer 111, which have different lengths. Correspondingly, the connecting element 106 can be used to form four connections, each with a first contact surface on a line and each with a second contact surface on a line oblique to this line.

11 shows a second arrangement 109 of contact surfaces 102, 103 connected to each other. This arrangement 109 differs from the arrangement 109 of FIG. 6 in that the contact surfaces 2, 3 are not provided on different areas 104, 105 of the part 110. Instead, the first contact surface 102 is provided on the first part 110 and the second contact surface 103 is provided on the second part 113. The two parts 110, 113 are not provided parallel to each other. It is shown as an example that the two parts are at an angle of 90° to each other. Arrangements with different angles are possible as well. The features of the presence of separate parts 110, 113 and the feature that the contact surfaces 102, 103 are not parallel to each other are independent of each other. This means that for example the areas 104, 105 of the part 110 can also be at an angle to each other.

In FIG. 11, the two parts 110, 113 form an angled device, on the inside of which the connecting element 106 is provided. Alternatively, the connecting element 106 can be provided on the outside of the angled device. In FIG. 11, the outside of the angled device is formed by the left side of the first part 110 and the lower side of the second part 113.

1 Nanowire 2 First part 3 Second part 4 Contact surface of first part 5 Contact surface of second part 6 First connection element 7 First connection surface 8 Second connection surface 9 Device 10 First side 11 Second side 12 Device 13 Functional element 14 Second connection element 15 Device 16 Third part 17 Fourth part 18 Contact surface of third part 19 Contact surface of fourth part 20 Third connection surface 21 Fourth connection surface 101 Nanowire 102 First contact surface 103 Second contact surface 104 First region 105 Second region 106 Connection element 107 First connection surface 108 Second connection surface 109 Device 110 First part 111 Layer 112 Initial body 113 Second part

Claims (12)

A method for connecting a first part (2) to a second part (3), comprising the steps of:
a) providing a connecting element (6),
The connecting element (6) comprises a number of nanowires (1) on a first connecting surface (7) on a first side (10) of the connecting element (6) and on a second connecting surface (8) on a second side (11) of the connecting element (6) opposite to the first side (10),
the first connecting surface (7) and the second connecting surface (8) are electrically insulated from each other ;
the connecting element (6) being made of a polymer ;
b) mating the contact surface (4) of the first part (2) with the first connecting surface (7) of the connecting element (6);
and c) mating the contact surface (5) of the second part (3) with the second connecting surface (8) of the connecting element (6). 2. The method of claim 1 ,
At least one of steps b) and c) is performed at room temperature.
Method. 3. A method according to claim 1 or 2, comprising:
d) heating at least each of said contact surfaces (4, 5) to a temperature of at least 90° C.,
Method. The method according to any one of claims 1 to 3,
the connecting element or the first part or the second part or a combination thereof is subjected to ultrasonic action in at least one of steps b) and c);
Method. The method according to any one of claims 1 to 4,
The connection element (6) provided in step a) comprises a number of nanowires (1) on a third connection surface (20) of the first side (10) of the connection element (6) and on a fourth connection surface (21) of the second side (11) of the connection element (6),
the third connection surface (20) and the fourth connection surface (21) are connected to each other in an electrically conductive manner;
The method comprises:
b') mating a contact surface (18) of a third part (16) with said third connecting surface (20) of said connecting element (6);
and c') mating a contact surface (19) of a fourth part (17) with said fourth connecting surface (21) of said connecting element (6). A connecting element (6) for connecting the first part (2) to the second part (3),
The connecting element (6) comprises a number of nanowires (1) on a first connecting surface (7) on a first side (10) of the connecting element (6) and on a second connecting surface (8) on a second side (11) of the connecting element (6) opposite to the first side (10);
The first connecting surface (7) and the second connecting surface (8) are electrically insulated from each other ;
The connecting element (6) is made of a polymer .
Connecting element (6). A connecting element (6) according to claim 6,
The connecting element (6) is of a film-like construction,
Connecting element (6). A connecting element (6) according to claim 6 or 7,
The thickness of the connecting element (6) is at most 5 mm.
Connecting element (6). A connecting element (6) according to any one of claims 6 to 8,
the specific electrical resistivity of the material of the connecting element (6) in the region between the first connecting surface (7) and the second connecting surface (8) is at least 10 ⁵ Ωm at room temperature;
Connecting element (6). A connecting element (6) according to any one of claims 6 to 9,
the connecting element (6) being formed in the region between the first connecting surface (7) and the second connecting surface (8) from a ceramic material;
Connecting element (6). A connecting element according to any one of claims 6 to 10,
a number of nanowires (1) on a third connection surface (20) of the first side (10) of the connection element (6) and on a fourth connection surface (21) of the second side (11) of the connection element (6),
The third connection surface (20) and the fourth connection surface (21) are connected to each other in an electrically conductive manner.
Connection element. An apparatus (9), comprising:
a first part (2) connected to a connecting element (6) by a number of nanowires (1) on a first connecting surface (7) on a first side (10) of said connecting element (6);
a second part (3) connected to said connecting element (6) by a multiplicity of nanowires (1) on a second connecting surface (8) on a second side (11) of said connecting element (6) opposite to said first side (10),
the first connecting surface (7) and the second connecting surface (8) are electrically insulated from each other ;
The connecting element (6) is made of a polymer .
Apparatus (9).

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