CN115298817A

CN115298817A - Hook and loop welding of multiple metals

Info

Publication number: CN115298817A
Application number: CN202180021771.7A
Authority: CN
Inventors: 奥拉夫·伯莱姆; F·达辛格; S·奎德努; F·鲁斯塔
Original assignee: Nanowire Co ltd
Current assignee: Nanowire Co ltd
Priority date: 2020-03-18
Filing date: 2021-03-08
Publication date: 2022-11-04
Also published as: DE102020107515A1; TW202205584A; KR20230020386A; JP2023522569A; EP4122010A1; WO2021185616A1

Abstract

A connection element (6) for connecting a first component (2) to a second component (3) has a respective plurality of nanowires (1) on a first connection face (7) on a first side (10) of the connection element (6) and on a second connection face (8) on a second side (11) of the connection element (6) opposite the first side (10), the nanowires (1) on the first connection face (7) and the nanowires (1) on the second connection face (8) being formed from different materials. A method for connecting a first component (2) to a second component (3), comprising: a) providing a connecting piece (6), b) bringing together the contact surface (4) of the first component (2) with the first connection surface (7) of the connecting piece (6), and c) bringing together the contact surface (5) of the second component (3) with the second connection surface (8) of the connecting piece (6). The nanowire (1) on the first connection face (7) may be made of metal and/or the nanowire (1) on the second connection face (8) may be made of metal. The nanowire (1) on the first connection face (7) may be made of the material of the contact face (4) of the first component (2) and/or the nanowire (1) on the second connection face (8) may be made of the material of the contact face (5) of the second component (3). The first component (2) may be a circuit board, the contact surface (4) of the first component (2) being made of copper. The second component (3) may be an electronic component, the contact surface (5) of the second component (3) being made of silver, nickel and/or gold. The first component (2) and the second component (3) may be semiconductor components fastened to each other on top of each other. It is also possible to attach a component such as a sensor (as the first component (2)) to a wall or a base (as the second component (3)). The method may further comprise a step d) of heating at least the contact surfaces (4, 5) to a temperature of at least 90 ℃. The heating may be performed after the connection is formed according to steps b) and c), or alternatively, steps b) and c) and step d) may be performed at least partially simultaneously. The connection (6) may be a foil connection.

Description

Multi-metal hook and loop welding

The present invention relates to a method and a connector for connecting a first component to a second component, and also to an assembly of two interconnected components, in particular in connection with components of an electronic device.

In a wide variety of applications, it is desirable to interconnect objects. For example, two metal objects or two objects made of different materials may need to be connected to each other. This is particularly the case in electronic devices. Various methods are known from the prior art for forming such connections. In particular, methods are known which connect electrically conductive or electrically conductive elements, for example made of copper, by welding, brazing or soldering, gluing, screwing, riveting or embossing. In this method, the prepared surfaces are precisely oriented relative to each other and connected to each other. Thus, the objects to be connected need to be clearly geometrically defined and prepared in terms of their extension and their connection sites in the longitudinal direction. In addition, preparations for producing the connection, such as, for example, drilling or providing a corresponding connection, must be carried out beforehand. Here, the bonding, screwing and riveting techniques are room temperature processes. In contrast, welding, soldering, and brazing are hot working processes where molten metal is generated and forced into the joint in a manner that the fill volume and metal interact.

Due to their considerable temperature input, which is usually up to 1400 ℃, welding has the disadvantage that, on the one hand, the objects concerned are heated considerably, so that there is a risk of ignition of the combustible material. Changes in the appearance of the surfaces of the objects to be connected may also occur, which may be problematic especially in the case of surfaces pretreated with paints, films or coatings. Many materials are also not weldable.

Brazing of e.g. copper may also cause the components involved in the connection to be heated significantly (in particular above 400 ℃) because of its considerable heat energy input. This may result in ignition of the combustible material.

Soldering of copper, for example, can have the disadvantage that, on the one hand, the shear strength of the connection is lower than desired, and, on the other hand, the alternating temperature load in soldering leads to separation of the metals and thus to brittle fracture of the connection. This may result in connection failure. In addition, soldering has the disadvantage that they have a much greater connection transfer resistance than, for example, pure copper. Another disadvantage of soldered connections is the low mechanical fatigue strength, which is usually present only up to about 120 ℃. The corrosion resistance of such connections against acid media is also often insufficient.

During the bonding of particularly conductive components, such as, for example, copper components, there is often the disadvantage that the conduction resistance is significantly adversely affected by said bonding. The mechanical requirements in terms of mechanical strength of the connection cannot always be met by a conductive adhesive bond. This is also the case if a sufficiently high mechanical strength is present, usually only up to a temperature range of only 120 ℃. This may make it impossible to use in particular in warm or hot environments and/or with hot media.

In the case of screwing and riveting, the parts are already joined together in a very precise manner. The required holes and assembly by means of screwing or riveting also often lead to a visual impairment of the visual and mechanical appearance of the entire structure. In addition, in terms of construction, it is necessary to ensure that the exact location where the connection is to be made is known in advance. The availability of said components that are not defined in terms of length may thus be more difficult to manufacture or prevented. In addition, in the case of such a connection, there is usually a residual gap between the components. Due to capillary action, moisture may enter the residual gap and thus corrosion may occur. Corrosion may damage the connection. The electrical resistance and/or heat transfer resistance of the connection may also increase. In addition, holes for screws or rivets may cause leakage in the connection area. This may make it more difficult to use such a connection for e.g. containers or pressure systems, especially if an additional sealing mechanism is required.

In view of this, it is an object of the present invention to solve or at least alleviate the technical problems discussed in connection with the prior art. The invention is intended in particular to propose a method and a connecting element for connecting a first component to a second component, and also an assembly of two components connected together, in which case there is a connection or a connection between the components in a very reliable and simple manner, which is in particular mechanically stable and has a very good electrical and/or thermal conductivity.

The object is achieved by a method, a connection and an assembly according to the features of the independent claims. Further advantageous refinements are specified in the respective dependent claims. The features specified individually in the claims can be combined with one another in any desired technically suitable manner and can be supplemented by explanatory facts from the description, further design variants of the invention being highlighted.

According to the invention, a method for connecting a first component to a second component is proposed. The method comprises the following steps:

a) Providing the connector with a respective plurality of nanowires on a first connection face on a first side of the connector and on a second connection face on a second side of the connector opposite to the first side, wherein the nanowires on the first connection face and the nanowires on the second connection face are formed of different materials,

b) Bringing together the contact surface of the first part and the first joint surface of the joint, an

c) Bringing together the contact surface of the second component with the second connection surface of the connection piece.

The first and second components are preferably electronic components such as, for example, semiconductor components, computer chips, microprocessors or printed circuit boards. The first component and/or the second component are preferably at least partially electrically and/or thermally conductive.

Electrical and/or thermal conductivity in the sense used herein is present in metals such as, for example, copper, which is often referred to as "electrically conductive" or equivalently as "electrically conductive" or "thermally conductive". In particular, materials that are generally considered to be electrically and/or thermally insulating are not intended to be considered to be electrically and/or thermally conductive herein.

The method is not limited to application in the field of electronic devices. For example, a component such as a sensor (as a first component) can also be mounted on a wall or a base (as a second component) according to the method. By means of the method, in particular a mechanically stable and electrically and/or thermally conductive connection can be formed between the first component and the second component. The method can then be applied in all fields requiring a corresponding connection between two components. The method is also not limited to a certain size of the component. The method is then suitable, for example, for the connection of larger components for applications in the field of (micro) electronics or on a macroscopic level.

The components may be connected to the connector by respective contact surfaces. The contact surface is in particular a spatially characterized area of the surface of the respective component. In particular, the contact surface is preferably characterized by the formation of the connection. This means that the contact surface is initially indistinguishable from the rest of the surface of the component and is distinguished only by the connection being formed such that the contact surface is the surface at which the connection is formed. In this case, the contact surface is initially only conceptually distinguished from the remaining surface of the component. In the region of the contact surface, the nanowires of the connector can contact the respective component.

Each contact surface is preferably a region of simple contiguous shape of the surface of the respective component. Alternatively, the respective contact surface of the first part and/or the second part is subdivided into a plurality of individual sub-areas of the surface of the respective part. The contact surface may then comprise more than two separate portions of the surface of the respective component. The contact surface may be electrically and/or thermally conductive or insulating. The contact surface is preferably electrically and/or thermally conductive, so that an electrically and/or thermally conductive connection can be formed.

The component preferably has a rigid design or has at least one rigid surface on which a corresponding contact surface is provided. This means in particular that the component (or at least the contact surface) is preferably not flexible. With a rigid component or contact surface, the connection can be made in a particularly satisfactory manner according to the method. If, for example, one of the components should have an elastic design, the connection can be broken by the force exerted by the nanowire. However, depending on the exact situation, it may also be advantageous to carry out the method with flexible components or contact surfaces.

In the method, the connection between the first component and the connector is formed by a plurality of nanowires.

Nanowire shall here mean any body of material having a filamentous shape and dimensions in the range of a few nanometers to a few micrometers. The nanowires may for example have a circular, elliptical or polygonal base. In particular, the nanowires may have hexagonal bottom surfaces.

The nanowires on the first connection face and the nanowires on the second connection face are formed of different materials. The ability of the nanowire to form a connection between the connector and one of the components is particularly affected by the material of the nanowire. The connection may have different properties in relation to the nanowire material. In particular, the mechanical strength and electrical and/or thermal conductivity of the connection is affected by the nanowire material. Due to the fact that the nanowires on the two connection faces are formed of different materials, two connections having different properties can be formed. The connection can then also be considered as a promoter between the two components to be connected, since otherwise two components which cannot be connected to one another or can only be connected with difficulty can be connected to one another by the connection. Instead of a direct connection between two parts, which cannot be formed or can only be formed with difficulty, a first connection can be formed between the first part and the connecting piece and a second connection can be formed between the second part and the connecting piece. By appropriate selection of the materials of the nanowires and of the connectors, the first connection and the second connection can be formed in a more efficient manner than a direct connection between the first component and the second component.

All of the nanowires involved in the connection are preferably formed of the same material. This means that preferably all nanowires on the first connection face are formed of a first material and all nanowires on the second connection face are formed of a second material different from the first material. The nanowires are particularly preferably formed entirely of an electrically and/or thermally conductive material. An electrically and/or thermally conductive connection can thus be formed. The connecting element is preferably also electrically and/or thermally conductive. The connection between the first component and the second component is completely electrically and/or thermally conductive if the nanowires at both connection faces and the connection are electrically and/or thermally conductive.

The nanowires preferably have a length in the range of 100nm to 100 μm, in particular in the range of 500nm to 30 μm. In addition, the nanowires preferably have a diameter in the range of 10nm to 10 μm, in particular in the range of 30nm to 2 μm. The expression "diameter" relates here to a circular base surface, similar definitions of diameter being taken into account in the case of a base surface which is not. All nanowires used particularly preferably have the same length and the same diameter.

In the method described so far, the components are indirectly connected to one another via the connecting element. This has the advantage that the nanowires do not have to be provided on all components. It is sufficient to have a nanowire on the connector. In particular, the nanowires are preferably not arranged on the contact surfaces of the components, but only on the connection surfaces of the connecting elements. This may make the implementation of the method easier and in particular also extend the field of application of the method to those parts which are not available for the growth of the nanowires or which can only be done with difficulty. The growth of the nanowires may also be effected locally, separately from the component. However, alternatively, it is also preferred to provide a respective plurality of nanowires at the contact surface of the first component and/or at the contact surface of the second component.

The connecting element preferably has a flexible configuration. Alternatively, the connection preferably has a rigid configuration. The connecting element can be designed, for example, in the form of a small rigid metal plate.

The connector is preferably formed of plastic. For example, the connector may be formed from a polymer, in particular polycarbonate, PVC, polyester, polyethylene, polyamide and/or PET. The connection may also be formed, for example, of ceramic material, silicon, alumina or glass. In addition, the connector may be formed of stainless steel, aluminum, or non-ferrous metals. The connector is also preferably formed from a composite material comprising several of the above materials.

In step a), a connecting element is provided, which has two connecting surfaces. Both of the connection faces have a plurality of nanowires. The first connection face is arranged on a first side of the connection piece and the second connection face is arranged on a second side of the connection piece. The first and second sides of the connector are disposed opposite each other. The first side of the connector is the side of the connector that faces the first component after the connection is made. The second side of the connector is the side of the connector that faces the second component after the connection is made. The components can then be connected by the method, since the contact surfaces of the two components are arranged opposite one another on both sides of the connection after the connection has been made. The spacing between the two contact surfaces is in this case only caused by the thickness of the connecting element and the space occupied by the nanowires.

The connection is provided in step a) of the method. In this case, providing on the one hand means that a connection configured as described is provided as part of the method. In particular, the nanowires can be applied to the connection surface as part of a method, in particular by means of current propagation. On the other hand, however, the provision also comprises the use of a connecting element on which the nano-filaments are already arranged on the connecting surface. Accordingly, a correspondingly prepared connection can be obtained, for example, from a supplier and used in the method. A connection in the sense that a ready connection is obtained in this way is also provided.

It is preferred to provide the nanowires at the connection surfaces in such a way that the nanowires are substantially perpendicular (preferably perpendicular) to the respective connection surface. The entire nanowire at the junction face may be particularly referred to as a nanowire plateau. The nanowires may be provided on the connection surface in any desired orientation. It is also possible to divide the connecting surface into a plurality of (connected together or separated) subregions, wherein the nanowires are oriented differently in the respective different subregions. In this way, a particularly stable connection can be achieved, which in particular also withstands shear forces in a particularly satisfactory manner. In addition, the nanowires may be designed differently at different points of the connecting surface, in particular with regard to their length, diameter, material and density (nanowire density describes how many nanowires are provided per unit area).

A connection may be understood in particular as an intermediary between a first component and a second component. Any solid object adapted to be arranged between the contact surfaces of the components for the connection of the components is particularly considered to be a connecting element.

The connection surface is in particular a spatial characteristic region of the surface of the connection element on the respective side of the connection element. In particular, the connection surface may be characterized by the formation of a connection. This means that the connection surface is initially not distinguished from the remainder of the connection surface and is only distinguished by the formation of the connection in such a way that the connection surface is the region in which the connection is formed. In this case, the connection face is only conceptually distinguished from the remainder of the connection face before the connection is made. For example, the connection face of a surface connector may be characterized as being formed over a limited area of the connector (i.e., at the connection face) with the surface connection of the respective component.

The connecting surface is preferably as large as the corresponding contact surface and particularly preferably has its shape. However, the contact surface may also be larger or smaller than the corresponding connection surface and/or the contact surface and the corresponding connection surface may have different shapes.

The connection surfaces are preferably all areas of the connection element surface having a simple contiguous shape. Alternatively, the first connection face and/or the second connection face may be divided into a plurality of individual sub-regions of the connection element surface. The connection surface may then comprise more than two 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. As a result, the nanowires on the connection surface come into contact with the respective contact surface. In this case, the nanowires are connected to the corresponding contact surfaces, as a result of which a corresponding connection between the component and the connecting piece is formed.

The connection is formed in such a way that the nanowires, in particular their ends facing the respective contact surface, are connected to the contact surface. The connection is formed at the atomic level. This operation in an atomic manner is similar to what happens during sintering. The obtained connection may be tight, in particular to gases and/or liquids, i.e. corrosion of the connection and/or the joining component may be prevented or at least limited in the area of the connection. In particular, the connections formed can be considered to be all-metallic. The method may also be referred to as "clett welding" (Klett welding, hook and loop welding). This expresses that the connection is obtained by a plurality of nanowires and further by a plurality of elongated hair-like structures and heating. The plurality of nanowires may compensate for asperities and roughness of the contact surface.

The connecting surface (i.e. the forces such as van der waals forces act here at the atomic level) is particularly large in view of the nanowire dimensions in the nanometer range. Thus, the connection may have a good electrical and/or thermal conductivity and/or mechanical stability. For a good electrically and/or thermally conductive connection, the nanowires are preferably formed from an electrically and/or thermally conductive material. Here, copper, silver, nickel and gold are particularly preferably used. The contact surface is preferably also formed from an electrically and/or thermally conductive material, in particular containing copper, silver, nickel or gold. As mentioned above, the use of copper is not possible in particular in the case of soldered connections. The electrical and/or thermal conductivity of the connection may be large in view of the large surface of the connection obtained by the method. The good thermal conductivity of the connection may, for example, improve the cooling of the components involved in the connection. In particular, copper, silver and gold are preferably used for the nanowires and/or the contact areas.

The connection can also be made in a very simple manner without tools. It is only necessary to bring the parts to be joined together. Heating and pressing can optionally be performed, but is not absolutely necessary.

The method steps a) to c) are preferably carried out in the stated order, in particular in succession. In particular, step a) is preferably performed before steps b) and c) are started.

If steps b) and c) are carried out in succession, the contact surface and the first connection surface of the first component, i.e. the first component and the connection piece, can initially be brought together (step b)). The connecting element brought together with the first component according to step b) can then be brought together with the second component in such a way that the contact surface and the second connecting surface of the second component are brought together (step c)).

Steps b) and c) may alternatively be performed simultaneously, temporally overlapping or sequentially. This is for example possible because the connection is held between the two parts and the parts are moved simultaneously from both sides towards the connection.

In a preferred embodiment of the method, the nanowires at the first connection face and/or the nanowires at the second connection face are formed of the respective metal.

The nanowires at the first connection face and the nanowires at the second connection face are preferably formed of respective metals.

The nanowires on the first connection face are preferably all formed of the first metal. The nanowires on the second connection face are preferably all formed of the second metal.

In particular with nanowires made of metal, a mechanically robust and electrically and/or thermally conductive connection can be formed.

In a further preferred embodiment, the nanowires on the first connection face are formed from the contact face material of the first component and/or the nanowires on the second connection face are formed from the contact face material of the second component. .

Preferably, the nanowires on the first connection face are formed from the contact face material of the first component and the nanowires on the second connection face are formed from the contact face material of the second component.

The connection between the nanowire and the respective contact surface is formed in a particularly satisfactory manner if the nanowire is formed from the same material as the contact surface. This is because the connection is formed at the atomic level. Connections between objects made of different materials are more difficult to achieve because of the different lattice structures of the materials. There have been instances where different lattice constants may make connections more difficult to form or may adversely affect the performance of the formed connections.

Said drawback of the connection between objects made of different materials will also occur if the first and second components are to be directly connected to each other by means of nanowires. In that case, it would be necessary to form connections at the atomic level between nanowires made of different materials or between nanowires made of different materials and the contact surface. These problems are overcome in the present method by the connection. The connection between the nanowire and the connector is not achieved by a simple assembly operation. Instead, the nanowires are grown onto the connector. As a result, a very tight connection can be formed. The connection may thus be formed of a homogeneous material. Alternatively, the connection surfaces of the connector may be formed of different materials, preferably each formed of the material of the corresponding nanowire.

The first connection face is preferably formed of a first material, preferably corresponding to the material of the nanowires on the first connection face. The second connection surface is preferably formed of a second material, which preferably corresponds to the material of the nano-wires on the second connection surface. The connecting element is preferably formed from a third material and is coated with the first material in the region of the first connecting surface and with the second material in the region of the second connecting surface. The connection surface is formed by these coatings. The third material is preferably electrically and/or thermally conductive. Alternatively, the third material is preferably electrically and/or thermally insulating. In this case, the connection element preferably has a respective locally electrically conductive connection between a subregion of the first connection face and a subregion of the second connection face.

Instead of the third material, the connecting element can also comprise a plurality of different materials, which are arranged, for example, in layers. In this case, the connection may also be referred to as a composite strip.

As an alternative, the connecting element is preferably formed from a first material and coated with a second material in the region of the second connecting surface. As a further alternative, the connecting element is preferably formed from a second material and is coated with the first material in the region of the first connection face.

In a further preferred embodiment of the method, the first component is a printed circuit board, wherein the contact surface of the first component is formed of copper.

In a further preferred embodiment of the method, the second component is an electronic component, wherein the contact surface of the second component is formed from silver, nickel and/or gold.

By means of the method, it is possible in particular to fasten an electronic component, such as a MOSFET or an IGBT module, having silver-made terminals as contact faces as second component to a printed circuit board having copper contacts as contact faces as first component.

In another preferred embodiment of the method, step b) and/or step c) are performed at room temperature.

The connection between the contact surface and the connection surface can already be formed at room temperature. In this case, the two parts are preferably pressed together to form the connection. Preferably, the pressure used here lies in the range between 5MPa and 200MPa, in particular in the range between 15MPa and 70 MPa. A pressure of 20MPa is particularly preferred.

Heating preferably also does not take place after the end of steps b) and c). As a result, damage to the component due to the influence of temperature can be prevented.

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

The contact surface is heated to a temperature of at least 90 c (as the lowest temperature), preferably to a temperature of at least 150 c (as the lowest temperature). The temperature is preferably 200 ℃. The heating is preferably effected to a temperature of at most 270 c, especially at most 240 c. In this embodiment, it is also preferred to perform steps b) and/or c) at room temperature. This means that the heating only takes place after the formation of the connection according to steps b) and c). The connection thus formed is strengthened by heating.

The heating according to step d) connects the nanowires to the contact surfaces in a particularly satisfactory manner. Accordingly, it is sufficient to heat only the contact surface. In practice, with such heating, it is often not possible to distinguish whether the heating is performed at the contact surface, the nanowire, the connection, part or the whole of the first component and/or part or the whole of the second component. This is the case in particular if thermally conductive materials are used. For the formation of the connection, no (co-) heating of the parts of the non-contact surfaces is required, but this is not disadvantageous. The heating according to step d) can then be effected in particular in such a way that the first component, the second component and the connecting piece are heated intensively, for example in an oven. Alternatively, however, heat can also be introduced locally into the connection region, in particular in the region of the contact surface.

For the formation of the connection it is sufficient to reach the minimum temperature at least once in a short period of time. It is not necessary to maintain a minimum temperature. However, the temperature to which heating is carried out in step d) is maintained for at least 10 seconds, preferably at least 30 seconds. This ensures that the connection is made as desired. In principle, it is not disadvantageous to keep the temperature longer.

Steps b) and c) and also step d) may be performed in an at least partially temporally overlapping manner. Thus, for example, preheating can be carried out before or during steps b) and c), which can be understood as part of step d). It is also possible to heat the respective contact surfaces of the first component and/or of the second component before step d) so that the temperature required for forming the connection has been reached during the polymerization step according to step b) or c). In particular, step d) can also be started before step b) or c). In that case, step d) is performed because the temperature required according to step d) is at least temporarily present even after the end of step b) or c).

By means of the method, a connection between two components can be obtained without reaching temperatures to such an extent as in the case of welding or brazing, for example. This advantage can be utilized in this embodiment as such, unnecessary heating being dispensed with. For example, damage to the components can thus be avoided. Ignition of the combustible material can also be precluded because of the low temperatures. Accordingly, it is particularly preferred that the temperature of the first part and/or of the second part does not exceed 270 ℃, in particular 240 ℃, at any time during the process.

In a further preferred embodiment of the method, the first part and the second part are pressed onto the connection at a pressure of at least 5MPa, in particular at least 15MPa, and/or at most 200MPa, in particular 70MPa, at least during part of the heating. This can be achieved in particular in that the two parts are pushed towards one another, while the connecting piece is arranged between the two parts.

Preferably, the pressure used lies in the range between 5MPa and 200MPa, in particular between 15MPa and 70 MPa. A pressure of 20MPa is particularly preferred.

The pressure is preferably above the specified lower limit at least during the period in which the temperature exceeds the lower limit specified for this. In this connection, the nanowires and the contact surface are then exposed to the effect of a corresponding pressure and a corresponding temperature at least during said period. As a result, the connection can be formed by the action of pressure and temperature.

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

The first connection face and the second connection face are preferably arranged parallel to each other.

In this embodiment, the connection may be arranged between two components to be connected. In this case (no separate connection is to be formed), the connection element is only such that the contact surfaces are not arranged directly next to one another, but are spaced apart from one another, in particular by the thickness of the material of the connection element. The orientation of the contact surfaces relative to each other remains unaffected by the connection.

Alternatively, for example, the first connection surface and the second connection surface can also be arranged at different locations of the respective, in particular planar, surfaces of the connection piece. In that case, the first component may be connected to the connector at a first of said positions, and the second component may be connected to the connector at a second of said positions.

In another preferred embodiment of the method, the first component and the second component are semiconductor components fastened to each other.

In this embodiment, the connection element is preferably formed from an electrically insulating third material, coated with an electrically conductive first material in the region of the first connection face and coated with an electrically conductive second material in the region of the second connection face. The connection surface is formed by the coating. The first connection surface and the second connection surface are preferably designed in such a way that electrically insulated subregions of the respective connection surface are produced. The connector preferably has a locally conductive connection between the top side and the bottom side of the connector. The sub-region of the first connection face can then be connected to the sub-region of the second connection face by means of a local connection in an electrically conductive manner. This can be used for contact connection of contacts of semiconductor components. The sub-regions are configured in the form of conductor tracks by means of which signals can be distributed.

With the aid of the connecting element thus formed, semiconductor components, such as semiconductor chips, microcontrollers, RAM or DRAM, can be fixed and simultaneously contact-connected. For example, the first DRAM may then be connected as a first component to the bottom of the housing, for example by a simple nanowire connection. By the method, the second DRAM may be secured to the first DRAM as a second component. The connection between the DRAMs is preferably dimensioned such that it can be fastened to the bottom of the housing in addition to the first DRAM. This connection is preferably also used for signal distribution, in particular for the second DRAM. Thus, the contacts of the second DRAM can be connected to sub-regions of the first connection face that are electrically insulated from each other. The respective local electrically conductive connection in the electrically insulated connecting part can be such that the conductor tracks formed in this way on the top side of the connecting part are connected to the contacts on the housing bottom, optionally by means of conductor tracks on the bottom side of the connecting part which are electrically insulated from one another. It is also possible to connect the contacts of the second DRAM directly to the contacts of the first DRAM via respective local conductive connections. The other DRAMs may be secured to the second DRAM in a similar manner. Thus, for example, 10 DRAMs can be stacked and contacted.

As another aspect, a connector for connecting a first component to a second component is presented. The connector has a respective plurality of nanowires on a first connection face on a first side of the connector and a second connection face on a second side of the connector opposite the first side. The nanowires at the first connection face and the nanowires at the second connection face are formed of different materials.

The particular advantages and design features of the method described above may be applied and applied to the connector and vice versa.

In a preferred embodiment, the connecting member is in a membrane-like configuration.

By membranous configuration is meant that the connecting member has a thickness that is much smaller than the extension of the connecting member in the remaining direction. In a preferred embodiment, the connecting element has a thickness of at most 5mm. The thickness of the connecting piece is preferably in the range between 0.05mm and 5mm, in particular between 0.1mm and 1 mm.

In addition, the connector is preferably in a strip configuration. In this embodiment, the mutually opposite first and second sides of the connecting piece are the two surfaces of the strip, which have a considerable surface area compared to all other surfaces (produced in view of the strip material thickness).

The strip material may be provided, for example, in the form of a roll. In this case, the nanowires may already be provided on the strip material and protected, for example, by a protective lacquer. Prior to use of the connector, the protective lacquer may be removed and the nanowires exposed as a result. The respective required strip material portions can be separated from the roll to be used.

In this embodiment, the connector may also be referred to as a "connector tape" and in particular as a "cleter weld tape" (hook and loop weld tape).

In another embodiment, the connection is at least partially electrically and/or thermally conductive.

In particular, in this embodiment, the connection formed may have good electrical and/or thermal conductivity.

Alternatively, the first connection face and the second connection face are preferably electrically insulated from each other.

If the electrical resistance between the first connection surface and the second connection surface is determined to be at least 100k Ω, as measured by a four-point measurement, under the following conditions: room temperature, air humidity 20%, measured at constant voltage (i.e. not at alternating voltage), measured with respective electrodes on the first connection face and the second connection face, at 1cm ² The electrodes contacting the respective connection faces in area, the first connection face and the second connection face are in any case intended to be considered electrically insulated from one another.

If the connection surfaces are electrically insulated from one another, an electrically insulating but mechanically stable and optionally also thermally conductive connection can be formed between the contact surfaces. Preferably, the specific resistance of the connector material in the region between the first connection face and the second connection face is at least 10 at room temperature ⁵ Ω m, preferably at least 10 ⁸ Ωm。

The detailed description described for the resistivity of the connector material relates to measurements at constant voltage. When an alternating voltage is applied, results may be obtained that may be particularly dependent on variations in the frequency of the alternating voltage.

At least 10 ⁵ Omega m, preferably at least 10 ⁸ Said value of Ω m relates to the material of the connecting element. The resistivity of various materials can be obtained in the specialist literature, for example in tables. See such specification herein. If the connection is formed entirely of a particular material, thenThe electrical resistivity of the material of the joining component to be used here is the value specified in the specialist literature for the particular material in question. This definition is meant to exclude all effects that are not caused by the material but, for example, by the shape of the connecting element. If the connection is made of different materials, the resistivity of the individual materials can be ascertained from the specialist literature and the overall resistivity of the connection material, i.e. the material composition, can be ascertained. If no specific resistance value of the material used is found in the specialist literature, said value can be ascertained by measurement.

Electrical insulation between the connection faces can be achieved in this way if the connection is formed from a third material and is coated with the first material in the region of the first connection face and with the second material in the region of the second connection face, the third material being electrically insulating. In this case, the first material and the second material may be electrically conductive. Thus, the metal nanowires can be grown on the connection surfaces consisting of the respective same material, but electrical insulation is still obtained by the third material. The connecting element is preferably formed from a ceramic material in the region between the first connection face and the second connection face.

As another aspect, an assembly is presented, comprising:

-a first part connected to the connector by a plurality of nanowires at a first connection face on a first side of the connector, and

a second part connected to the connector by a plurality of nanowires at a second connection face on a second side of the connector opposite to the first side,

the nanowires on the first connection face and the nanowires on the second connection face are formed of different materials.

The particular advantages and design features of the method and connector described above can be adapted and transferred to the assembly. The assembly is preferably produced by the method. The connection piece is preferably designed as described.

The present invention and the technical field will be discussed in more detail below based on the figures. The figure shows a particularly preferred embodiment, but the invention is not limited to said embodiment. It should be particularly noted that the figures and in particular the proportions shown are purely diagrammatic. The figures each schematically show:

figure 1 shows a diagrammatic representation of a method according to the invention for connecting two components,

figure 2 shows a diagrammatic representation of an assembly according to the invention consisting of two parts which are connected to one another according to the method of figure 1,

FIG. 3 shows a first embodiment of a connector in the assembly of FIG. 2, an

Fig. 4 shows a second embodiment of a connector in the assembly of fig. 2.

Fig. 1 shows a method of connecting a first component 2 to a second component 3. The reference numerals used relate to fig. 2. The method comprises the following steps:

a) On a first connection face 7 on a first side 10 of the connection element 6 and on a second connection face 8 on a second side 11 of the connection element 6, opposite to the first side 10, the connection element 6 is provided with a corresponding plurality of nanowires 1,

b) Bringing together the contact surface 4 of the first component 2 and the first connecting surface 7 of the connecting piece 6, and

c) Bringing together the contact surface 5 of the second component 3 and the second connection surface 8 of the connection piece 6.

The nanowires 1 are formed of different materials. In the example described here, the nanowires 1 on the first connection surface 7 are formed from copper and the nanowires 1 on the second connection surface 8 are formed from silver. The first part 2 is a printed circuit board and the second part 3 is an electronic component such as a MOSFET or IGBT module.

Steps b) and/or c) are preferably carried out at room temperature. The method may further comprise the following optional steps indicated by the dashed boxes in fig. 1: d) At least the contact surfaces 4,5 are heated to a temperature of at least 150 c.

Fig. 2 shows an assembly 9, which can be obtained by the method of fig. 1. The assembly 9 comprises a first part 2 connected to the connector 6 by a plurality of nanowires 1 at a first connection face 7 on a first side 10 of the connector 6. The assembly 9 further comprises a second component 3 connected to the connector 6 by the plurality of nanowires 1 at a second connection face 8 on a second side 11 of the connector 6 opposite to the first side 10. For this purpose, the first part 2 and the second part 3 have

respective contact surfaces

4, 5.

The nanowires 1 are formed of different materials as described in relation to fig. 1.

The connecting member 6 has a membrane-like configuration. The thickness of the connecting piece 6 is at most 5mm. The thickness of the connecting piece 6 can be shown in fig. 2 as the vertical extension of the connecting piece 6.

Fig. 3 shows a first embodiment of the connection element 6 of the assembly 9 of fig. 2. The first connection face 7 is formed of a first material 12 corresponding to the material of the nanowire 1 on the first connection face 7. The second connection face 8 is formed by a second material 13 corresponding to the material of the nanowire 1 on the second connection face 8. The connecting element 6 is formed from a third material 14 and is coated with a first material 12 in the region of the first connecting surface 7 and with a second material 13 in the region of the second connecting surface 8.

Fig. 4 shows a second embodiment of the connection element 6 in the assembly 9 of fig. 2. In this case, the connecting element 6 is formed from a first material 12 and is coated with a second material 13 in the region of the second connecting surface 8. The first connection face 7 is not formed by a coating, but by the side of the first material 12 which is located at the bottom side in fig. 4.

List of reference numerals

1. Nano-filament

2. First part

3. Second part

4. Contact surface of first part

5. Contact surface of second part

6. Connecting piece

7. First connection face

8. Second connecting surface

9. Assembly

10. First side

11. Second side

12. First material

13. A second material

14. A third material.

Claims

1. A method for connecting a first component (2) to a second component (3), the method comprising:

a) Providing a connector (6), the connector (6) having a respective plurality of nanowires (1) on a first connection face (7) on a first side (10) of the connector (6) and on a second connection face (8) on a second side (11) of the connector (6) opposite to the first side (10), wherein the nanowires (1) on the first connection face (7) and the nanowires (1) on the second connection face (8) are formed of different materials,

b) Bringing together a contact surface (4) of the first component (2) and the first connection surface (7) of the connection piece (6), and

c) Bringing together a contact surface (5) of the second component (3) and the second connection surface (8) of the connection piece (6).

2. The method according to claim 1, wherein the nanowires (1) on the first connection face (7) and/or the nanowires (1) on the second connection face (8) are formed of a respective metal.

3. The method according to any of the preceding claims, wherein the nanowires (1) on the first connection face (7) are formed from the material of the contact face (4) of the first component (2) and/or the nanowires (1) on the second connection face (8) are formed from the material of the contact face (5) of the second component (3).

4. The method according to any of the preceding claims, wherein the first component (2) is a printed circuit board and wherein the contact face (4) of the first component (2) is formed of copper.

5. Method according to any of the preceding claims, wherein the second component (3) is an electronic component and wherein the contact face (5) of the second component (3) is formed of silver, nickel and/or gold.

6. The method according to any one of the preceding claims, further comprising: d) At least the contact surfaces (4, 5) are heated to a temperature of at least 90 ℃.

7. The method according to any of the preceding claims, wherein the first and second components are semiconductor components fastened to each other.

8. A connector (6) for connecting a first component (2) to a second component (3), wherein the connector (6) has a respective plurality of nanowires (1) on a first connection face (7) on a first side (10) of the connector (6) and on a second connection face (8) on a second side (11) of the connector (6) opposite to the first side (10), and wherein the nanowires (1) on the first connection face (7) and the nanowires (1) on the second connection face (8) are formed of different materials.

9. The connection piece (6) according to claim 8, wherein the connection piece (6) is in a membrane-like configuration.

10. The connector (6) according to claim 8 or 9, wherein the thickness of the connector (6) is at most 5mm.

11. An assembly (9), the assembly (9) comprising:

-a first component (2), the first component (2) being connected to a connection (6) by a plurality of nanowires (1) at a first connection face (7) on a first side (10) of the connection (6), and

-a second component (3), the second component (3) being connected to the connection (6) by a plurality of nanowires (1) at a second connection face (8) on a second side (11) of the connection (6) opposite to the first side (10),

wherein the nanowires (1) on the first connection face (7) and the nanowires (1) on the second connection face (8) are formed of different materials.