KR20080034858A - Electrical connecting element - Google Patents

Abstract

In an electrical connecting element (1) comprising an electrical conductor (2) and an electrically conductive coating (3) it is proposed, in order to provide a connecting element which can be manipulated easily and whose coating can be heated rapidly, to form the surface of the coating (3) with a structured area and/or rough surface (5), at least in regions.

Description

Electrical connection element {ELECTRICAL CONNECTING ELEMENT}

 The present invention relates to an electrical connection element comprising an electrical conductor and an electrically conductive coating.

Electrically connected elements designed as flat wire and having a solder coating are already known.

The known connection elements are used to electrically connect several electrical elements, such as electrical elements, such as solar cells. For this purpose, the connecting element is heated and soldered with the electrical element by melting of the coating. Coated connection elements designed as punched parts or cut bands are also known.

The known connection elements have the disadvantage that a significant amount of energy is required to heat the coating as soon as possible. Otherwise, the coating cannot be heated sufficiently and quickly so that a stable connection between the electrical conductor and the electrical element cannot be obtained.

It is therefore an object of the present invention to provide a connection element of the kind mentioned above, the connection element being easily machined and a coating which can be quickly heated to ensure a stable connection between the electrical conductor and the electrical element at a high process speed. Has

According to the invention, this object is achieved by providing a structure and / or a rough surface on the surface of the electrical conductor in at least some areas.

This provides the advantage that the enlarged effective surface of the coating is available in comparison to the untreated surface and that the enlarged effective surface of the coating has high optical and / or thermal absorption. With regard to the soldering or joining process, the required heat can be introduced easily and quickly. The coating is preferably made of a uniform material on which the structures and / or rough surfaces are formed by surface treatment. The uniformity allows the entire layer to be heated evenly, making it available for a series of joining processes.

According to an embodiment of the invention, the electrically conductive coating may contain a solderable material such as solder, in particular tin. In this way, the coating itself can be made with soldered connections firmly attached in one processing step.

According to another embodiment, the electrically conductive coating may comprise an adhesive, preferably a conductive adhesive. As such, the coating may form a tightly attached adhesive bond.

The electrical conductor is advantageously made of a metal, in particular copper, or a metal alloy, in particular a copper alloy. This results in not only easy processing but also particularly high electrical conductivity.

In another refinement of the invention, the structure and / or rough surface may consist of a knurled or floating workpiece. The surface change can be made particularly easily and automatically, for example by rolling.

In other embodiments, the structure and / or rough surface may be formed through grinding. This makes it possible to provide coatings that are independent of the machining direction and have the same properties in all directions on the surface.

According to another embodiment, the structure and / or rough surface may be formed through etching. Likewise, a uniform surface change can be obtained by this chemical treatment.

In another refinement, the structure and / or rough side may extend in a cross section over only the area of the coating for the purpose of energy absorption. This eliminates the need to treat the entire surface of the coating. Thus, from the point of view of connecting the connecting element onto the electrical element, for example, only the surface area which is later emitted with infrared light has to be changed.

According to another variant, the structure and / or rough surface may extend in cross section over the entire perimeter of the electrical conductor. With this design, it is not necessary to pay attention to the part of the coating provided with the altered surface when using the connecting element according to the invention. Thus, the machining step is simplified.

The electrical conductor is advantageously made of a punched part or cut band. Thus, the connecting element is particularly easy to produce and the cost is reduced.

In a preferred embodiment, the electrical conductor can have a large length dimension relative to the cross section, for example designed as a wire. In this way, several electrical elements can be connected to one another via a connecting element in one machining step.

It is advantageous for the knurled or floating workpiece to extend essentially parallel to the longitudinal extension of the electrical conductor. This has the advantage that the floating or nulling processing part can be easily applied to continuous processing during the production of the connecting element. In addition, a uniform surface and thus uniform properties of the coating over the longitudinal extension are obtained in a particularly advantageous manner.

In other variations, the grinding direction may extend essentially parallel to the longitudinal extension of the electrical conductor. Also in this case, the surface treatment can be easily carried out in a continuous process. Likewise, a uniform surface and thus uniform properties of the coating over the longitudinal extension are obtained in a particularly advantageous manner.

In other embodiments, the electrical conductor may be of circular cross section. Therefore, a commercially available wire can be used.

In a particularly preferred embodiment, the electrical conductor can be designed in a cross section consisting of a shape out of circular shape, for example a shape designed with a square, in particular flat wire. Due to this design, particularly good attachment of the connecting element to the electrical element can be obtained with the aid of a large contact surface. In addition, the usable surface of the coating is expanded, which allows for easier heat entry.

In another embodiment, the surface of the coating may be provided with a structure and / or rough surface over the entire length of the connecting element. This allows particularly high heat entry as well as particularly simple production and processing. The structure and / or rough side can be formed in a series of processes during production, and the same properties of the coating are obtained at each site during the process.

The coating advantageously extends over the entire length of the connecting element. Here, there is an advantage that during the processing there is no need to pay attention to where the coating is located and where the surface protection for the electrical conductor can be obtained through the coating.

In a preferred use, the connection element according to the invention can be applied to solar cells. The stable implementation of the connection between the solar cell and the electrical conductor is of particular importance for this application and it is therefore particularly advantageous to apply the structure and / or rough side on the coating according to the invention.

In other embodiments, two or more of the cells may be connected to each other via other connecting elements in the present invention. As a result, several solar cells can be connected with the connecting element, resulting in a large unit, for example a solar module. The module can be encapsulated to protect the environment from the outside.

The aforementioned purpose is to:

1) coating the electrical conductor with an electrically conductive coating

2) applying the structure and / or rough side on the coating

3) the coating forms a tight bond between the electrical conductor and the element and attaches the resulting electrical connection element to the electrical element, the side having a structure and / or a rough surface, the electrical element in particular Achieved by a method for contacting the solar cells.

This provides an advantageous way to quickly execute the connection between the electrical conductor and the electrical element with a relatively small amount of energy.

In a preferred embodiment, an electrical conductor can be used which has a large length dimension relative to the cross section and is designed for example as a wire, preferably a flat wire. The electrical conductor may advantageously be applied on the electrical element along the longitudinal extension of the electrical conductor. In this way, many electrical elements can be connected to each other through a connecting element in one machining step.

The invention will be described in more detail in an exemplary manner with reference to the accompanying drawings, in which such embodiments are shown.

1 shows a first embodiment of a connecting element with an electrical conductor having an essentially circular cross section.

2 shows a second embodiment of a connecting element with a flat electrical conductor;

3 shows a third embodiment of a connecting element with a flat electrical conductor;

4 shows a fourth embodiment of a connecting element with a flat electrical conductor;

5 shows the effect of the bonding between the electrical connection element and the electrical element according to the invention.

6 shows another embodiment in which the coating surface and the surface of the electrical conductor are changed.

7 is a cell with two electrical connection elements applied to the cell.

8 is a solar module consisting of a plurality of solar cells connected to each other by an electrical connection element.

9 is a detailed view (A) of the solar module shown in FIG. 8 with two solar cells connected to each other by electrical connection elements;

According to the first embodiment, as shown in FIG. 1, the electrical connecting element 1 consists of an electrical connector 2 designed as a core. The electrical conductor 2 is provided with a coating 3 around it which may contain, for example, a solderable material. Alternatively, the coating 3 may also contain an adhesive. The coating 3 has a structure or rough surface 5 which can be formed by rolling, grinding, etching or the like. Thus, the effective area of the coating is larger than the effective area of the coating without this process step.

According to the second embodiment, as shown in FIG. 2, the electrical connector element 1 consists of an electrical conductor 2 designed as a flat wire. The electrical conductor has a non-circular, essentially rectangular cross section. As shown in FIGS. 2A and 2B, on the upper side of the electrical connector 2, a coating which is likewise electrically conductive is provided. As shown in FIGS. 2A and 2B, the upper side of the electrical conductor 2, ie the upper side of the coating 3, has a structure or rough surface 5. Alternatively, as shown in FIGS. 2A and 2B, the lower side of the electrical conductor 2 may also have a coating.

According to the third embodiment, as shown in FIG. 3, the electrical connection element 1 consists of an electrical conductor 2 designed as a flat wire similar to the embodiment example according to FIG. 2. The coating 3 shown in FIG. 3 has a structure and / or rough surface 5 on the upper side and the bottom side of the electrical connecting element 1. As the coating 3 is also applied to the cross section over the entire circumference of the electrical conductor 2, the versatility of the electrical connection element is obtained. During the processing, it is not necessary to pay attention to the exact position of the electrical connecting element 1. In addition, the electrical connection elements are protected from harmful ambient influences and corrosion. In this context, the coating need not be formed to the same thickness. Rather, more coatings may be applied, for example, on one side. On the other side the layer thickness is reduced, for example. In a particularly preferred method, the layer thickness at the side for contacting is greater than the layer thickness at the opposite side where the coating mainly serves a protective function.

According to the fourth embodiment, as shown in FIG. 4, the electrical connection element 1 consists of an electrical conductor 2 configured as a flat wire similar to the embodiment according to FIGS. 2 and 3. However, here, the surface of the coating 3 is changed only on the side of the electric conductor 2 for the purpose of energy absorption. Thus, the structure and / or rough side 5 extend in the cross section only over the outer periphery of the coating. However, the coating 3 is located in the cross section over the entire circumference so that the electrical conductor 2 is completely wrapped by the coating 3. Due to this, the electrical conductor 2 can be protected against environmental influences and corrosion. Also in this case, it does not have to be made the same thickness at all positions. Rather, more coatings may be applied, for example, on one side. On the other side, the layer thickness is reduced, for example. In a particularly advantageous manner, the layer thickness is greater on the side where contact is made than on the opposing side where the coating primarily functions.

The use of the electrical connection element according to the invention will be described below with reference to FIG. 5. In this case, the electrical connecting element of FIG. 5 has an electrical conductor 2 designed as a flat wire. The electrical connection element is applied on an electrical element 4, for example a solar cell, in such a way that in the direction of the energy input device the coating is arranged on the side with the structure and / or rough surface 5. The energy input device may be any type of device capable of sufficiently heating the coating material to achieve a stable connection. 5 shows a connecting element in which the electrical conductor 2 designed as a flat wire has a coating around it. In addition, as the coating has a structure and / or rough surfaces 5 on both sides of the connecting element 1, the connecting element 1 can be applied not only to the position shown but also to a 180 ° reversed position. When the coating 3 is made of a solderable material, the coating is heated and melted by, for example, infrared light. Due to this, the coating is bonded with the electrical element 4, and after cooling, a connection is made between the electrical conductor 2 and the electrical element 4.

In the whole embodiment, the surface 5 of the coating 3 can be of any kind of structure, such as grooves in the longitudinal and / or transverse directions, fluids in the longitudinal and / or transverse directions, longitudinal and / or transverse. And grinding marks in the direction. The rough side 5 may have one or more preferred directions or may be designed identically in all directions. The structure and / or rough surface 5 may be performed mechanically and / or chemically by etching.

In all embodiments, the coating 3 constitutes itself as a means for the connection of the electrical conductor 2 and the electrical element 4. When using the electrical connection element 1, no other connection means, for example solder or adhesive, is necessary.

In all embodiments, the coating 3 may be made of a solderable material. The large surface 5 of the coating 3 makes it possible to heat quickly in view of the formation of a solder connection between the electrical conductor 2 and the electrical element 4. The solder can be executed automatically. The solder can be performed by infrared light. When the coating consists of a solderable material, in particular solder, such as tin, the solder can be carried out without additional material. In this case, the solder required for the solder connection is the coating material itself.

When the conductive coating 3 according to another example contains an adhesive, it can serve as a means for the connection of the electrical conductor 2 and the electrical element 4. Also in this case, enhanced energy is introduced into the coating 3 such that a faster and more stable implementation of adhesive bonding between the electrical conductor 2 and the electrical element 4 is achieved by the enlarged surface of the coating 3. Obtained.

As shown in FIG. 6, the surface 6 of the electrical conductor 2 can be modified in addition to the treatment of the surface 5 of the coating 3. Thus, the electrical conductor 2 can likewise be designed with a structure and / or with a rough face 6. This has the advantage that an enlarged contact surface between the electrical conductor and the coating can be used and that the resulting adhesive strength is increased. The layer thickness of the coating to achieve the desired adhesive strength can be reduced.

In connection elements designed with known electrical connection elements and flat wires, the coating generally has a convex surface. However, in the connecting element according to the invention, the surface of the coating is flat and uniform due to the treatment of the surface of the coating. Thus, the electrical connection element according to the invention can be completely flat or uniform on its surface, at least in some areas. This has the advantage of being laid flat in applications on electrical elements such as solar cells, thus forming a stable junction. When soldered on a solar cell, in particular on an imprinted silver bus bar that serves as an opposing contact at the solder connection, the material is placed completely uniform, which results in a fairly good solder result.

In addition, the connecting elements, for example flat wires (the coating of which also has an essentially flat and uniform surface) are easier to handle. In particular, a vacuum gripper used for this application can grasp the uniform object more quickly and stably. In addition, the advantage that a wire having a uniform and flat surface can also be wound on the coil, saving more space, being faster and improving process stability. Thus, the wire, in particular flat wire, is easy to wind up and loosen in layers on the coil. In addition, straightness that can be damaged in case of irregular winding can be maintained. This provides an advantage in machinability for automation and therefore in manufacturing costs.

The electrical connection element 1 according to the invention can be used as a connector to the solar cell 4 in a particularly advantageous manner. As shown in FIG. 7, for example, two connecting elements 1 designed as flat wires are applied on the surface of the solar cell 4. Alternatively, other described connection elements according to the invention can also be used. When using a connecting element having a structure or rough electrical conductor with a rough surface as a connector to the solar cell, a high strip off force or tear off force is required to remove the connecting element from the solar cell. Required. It is also possible to reduce the coating thickness for defined peeling or cutting forces.

Several solar cells 4 can be connected to each other with the solar module 7 in any suitable manner by means of a connecting element 1. When using the connecting element 1 designed as a flat wire, the appearance shown in FIG. 8 with a continuous connecting band is obtained. Alternatively, the connection elements described otherwise in accordance with the invention can also be used, where no continuous connection bands can be seen when the connection is made using, for example, punching or cut bands.

Connecting two adjacent solar cells 4 of the solar module 7 is shown in FIG. 8. In this case, each upper side of the solar cell 4 is connected with the bottom side of the adjacent solar cell 4 by means of the connecting element 1 according to the invention.

Other embodiments according to the invention have only some of the features described above and one can contemplate each combination of features, in particular each combination of features from alternatively described embodiments.

Claims (21)

An electrical connecting element (1) comprising an electrical conductor (2) and an electrically conductive coating (3), Electrically connected element (1), characterized in that the surface of the coating (3) in at least some area is provided with a structure and / or a rough surface (5). The method of claim 1, Electrically conductive element (1), characterized in that the electrically conductive coating contains a solderable material, such as solder, in particular tin. The method of claim 1, Electrically conductive element (1), characterized in that the electrically conductive coating contains an adhesive, preferably a conductive adhesive. The method according to any one of claims 1 to 3, Electrically connected element (1), characterized in that the electrical conductor (2) is made of a metal, in particular copper or a metal alloy, in particular a copper alloy. The method according to any one of claims 1 to 4, Electrical structure (1), characterized in that the structure and / or rough surface (5) consists of a knurled or floating part. The method according to any one of claims 1 to 4, Electrical connection element (1), characterized in that the structure and / or rough surface (5) is formed by grinding. The method according to any one of claims 1 to 4, Electrical connection element (1), characterized in that the structure and / or rough surface (5) are formed by etching. The method according to any one of claims 1 to 7, Electrical connection element (1), characterized in that the cross section of the structure and / or rough surface (5) extends only over the region of the coating (3) for the purpose of energy absorption. The method according to any one of claims 1 to 7, Electrical connection element (1), characterized in that the cross section of the structure and / or rough surface (5) extends over the entire outer circumference of the coating (3). The method according to any one of claims 1 to 9, The electrical conductor element (1), characterized in that the electrical conductor (2) is made of punched parts or cut bands. The method according to any one of claims 1 to 10, The electrical conductor (1), characterized in that the electrical conductor (2) has a large length dimension compared to the cross section, for example designed as a wire. According to claim 6 and 11, Electrically connected element (1), characterized in that the knurling or floating workpiece extends essentially in parallel with the longitudinal extension of the electrical conductor (2). The method according to claim 7 and 11, Electrical grinding element (1), characterized in that the grinding direction extends essentially parallel to the longitudinal extension of the electrical conductor (2). The method according to any one of claims 11 to 13, Electrical connection element (1), characterized in that the electrical conductor (2) is circular in cross section. The method according to any one of claims 11 to 13, The electrical conductor (2) is characterized in that the electrical conductor (2) is non-spherical, for example rectangular in cross section, in particular designed as a flat wire. The method according to any one of claims 11 to 15, Electrically connected element (1), characterized in that the surface of the coating (3) is provided with a structure and / or a rough surface (5) along the entire length of the connection element (1). The method according to any one of claims 11 to 16, Electrical connection element (1), characterized in that the coating (3) extends along the entire length of the connection element (1). Cell (4) to which the electrical connection element according to any of claims 1 to 17 has been applied. In a solar module 7 consisting of two or more cells 4, The solar module, characterized in that the solar cell (4) is connected by means of a connection element (1) according to any of the preceding claims. In a method for contacting an electrical element, in particular a solar cell, a) coating the electrical conductors 2 with an electrically conductive coating 3, b) applying the structure and / or rough side 5 to the coating 3, c) applying on the electrical element 4 an electrical connecting element 1 having a structure and / or a side on which the rough side 5 is formed, wherein the coating 3 is applied to the electrical conductor 2 and the electrical; A method for contacting an electrical element characterized by forming a tight bond with the element (4). The method of claim 20, The electrical conductor 2 has a large length dimension relative to the cross section, for example designed as a wire, preferably a flat wire, characterized in that it is applied on the electrical element 4 along the longitudinal extension of the electrical conductor. A method for contacting an electrical element.

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