DE102022134476A1 - Method for producing an autoclavable electrical connection, printed circuit board with an autoclavable electrical connection, and electrically connected autoclavable electronic component - Google Patents

Abstract

The present invention relates to a method for producing an autoclavable electrical connection (11) between at least one conductor connection end (3a) of an electrical line (1) and at least one electrically conductively coated connection area (7) on a circuit board (6), wherein the electrical line (1) has at least one conductor (3) and an insulation (4) radially surrounding the conductor (3). The method comprises the following method steps:
- providing the electrical line (1), wherein the insulation (4) extends to at least one conductor connection end (3a), so that the conductor (3) can be contacted at a conductor cross-sectional area (3b) formed on the front side of the conductor connection end (3a),
- Arranging the conductor connection end (3a) at the connection area (7) of the circuit board (6),
- applying a conductive joining material (12) to the connection area (7) of the circuit board (6) and to the conductor connection end (3a) so that a material-locking, electrically conductive connection is established between the material of the connection area (7) and the conductor cross-sectional area (3b),
- Fastening the cable (1) with at least one fastening means (13) at least indirectly to the circuit board (6).
The invention further relates to a circuit board (6) with at least one such autoclavable electrical connection (1), as well as to an autoclavable electronic component with such an autoclavable electrical connection (1).

Description

The invention relates to a method for producing an autoclavable electrical connection between a conductor connection end of an electrical line having at least one electrically insulated conductor and an electrically conductive connection region on a circuit board. The invention further relates to a circuit board with at least one autoclavable electrical connection, preferably produced using such a method, between an electrical line having at least one electrically insulated conductor and an electrically conductive connection region on the circuit board. The invention also relates to an autoclavable electronic component, e.g. an electric motor, with at least one electrical component, wherein an electrical connection is formed between a conductor connection end of an electrical line of the electrical component having at least one electrically insulated conductor and an electrically conductive connection region on a circuit board.

Electrical cables consist of metallic conductors, typically in the form of individual wires or strands comprising multiple stranded wires, as well as at least one insulation surrounding the conductor, in particular the individual wire or stranded wires. Several electrical cables can be combined into a cable by an additional, common sheath.

The insulation is usually an insulating sheath made of electrically insulating material, e.g. PVC, that surrounds the conductor, or a lacquer insulation made of insulating lacquer that is applied to the conductor during production. In the case of a stranded wire, the individual stranded wires are usually provided with such lacquer insulation.

The thickness and weight of enamel insulation are very low compared to other insulating materials. Wire insulated with enamel insulation, so-called enamel wire, is therefore often used to build electrical coils, transformers and machines. Polyesterimides, for example, are used as insulating enamel. For self-supporting coils that are manufactured without a coil body, baked enamel wire is used. The enamel consists of a temperature-resistant base insulation and a cover layer that bonds together when heated, which bonds the individual turns to one another and thus gives the coil mechanical strength and stability. The insulation is preferably designed in such a way that it can withstand temperatures of at least 750°C, in particular at least 900°C, advantageously at least 1000°C.

To create an electrical connection between an insulated electrical conductor and, for example, a connection area on a circuit board, the insulation of the conductor is first removed to a certain length required for the connection. This is known as stripping. Stripping is carried out using, for example, automatic stripping machines, laser devices or soldering baths. The electrical connection is then made to the stripped area, e.g. by soldering.

There are applications in which the usual stripping techniques are not practical, not desired or not possible. For example, electronic devices for use in the medical field, e.g. dental or surgical hand instruments, must meet certain hygiene requirements. Among other things, they must be sterilizable. Autoclaving is considered to be a particularly reliable sterilization process. Here, sterilization takes place at high temperatures of 110 °C to 140 °C and increased pressure of 2 bar to 3 bar in an autoclave. The medical instruments must therefore be suitably durable and in particular have autoclavable electrical cables, e.g. cables with temperature-resistant lacquer insulation.

However, stripping temperature-resistant lacquer insulation is problematic. In particular, the practical soldering bath process, which can simultaneously remove the insulation and tin the stripped conductor material, cannot be used for some temperature-resistant lacquer insulations because the temperature of the soldering bath is not sufficient to burn off the lacquer insulation.

It is known that temperature-resistant paint insulation can be stripped by immersing it in caustic soda (caustic soda process). However, concentrated caustic soda is highly corrosive and special requirements apply with regard to storage and disposal. In addition, stripping with caustic soda is time-consuming.

Based on the aforementioned prior art, the invention is based on the object of providing a method for producing an autoclavable electrical connection between an electrically insulated conductor and a circuit board, which can be carried out simply and quickly and in particular avoids the problems of stripping insulation using caustic soda. Another object is to provide a circuit board with an autoclavable electrical connection and an autoclavable electronic component with autoclavable connections to components having a circuit board.

The above-mentioned object is achieved in a method according to the characterizing part of claim 1 in that the electrical line is first provided, with the insulation extending to at least one conductor connection end, so that the conductor can be contacted at a conductor cross-sectional area formed on the front side of the conductor connection end. The insulation preferably extends to the conductor connection end in such a way that the conductor can only be contacted via the front-side conductor cross-sectional area. The insulation extends in particular in such a way that it extends into an imaginary plane in which the front-side conductor cross-sectional area is also arranged.

The conductor connection end is then arranged on the connection area of the circuit board. The arrangement is carried out, for example, in such a way that the front-side conductor connection surface is arranged essentially parallel to a surface or essentially perpendicular to a surface of the circuit board. A conductive joining material is then applied to the connection area of the circuit board and to the conductor connection end so that a material-locking, electrically conductive connection is created between the material of the connection area and the conductor cross-sectional area. Finally, the cable is attached to the circuit board at least indirectly using at least one fastening means. The fastening means connects the cable to the circuit board, for example, materially, positively and/or force-fittingly.

The advantage of the method according to the invention is that the electrical connection is made exclusively by contacting the conductor cross-sectional area located at the end of the conductor connection end. Compared to the prior art, it is therefore not necessary to strip the conductor connection end in a separate process step, which considerably simplifies the method and saves time, additional machines and consumables such as immersion baths.

This is particularly advantageous for autoclavable cables that have temperature-resistant insulation, in particular lacquer insulation, because the method according to the invention can avoid the stripping with caustic soda solutions that has previously been common in this case.

When providing the electrical line, according to one embodiment of the method, a stranded wire with several stranded wires each having insulation is used as the electrical line. Stranded wires made of copper, copper alloys, aluminum or silver are preferably used. Stranded wires with insulation made of insulating varnish, in particular made of autoclavable material, e.g. polyesterimide varnish, are preferably used. For example, modified polyester(imide) and/or polyamideimide is used as the insulating varnish.

However, the electrical line can also be provided as a single wire, in particular made of copper, copper alloys, aluminum or silver. Preferably, single wire with an insulating sheath, in particular made of autoclavable material, e.g. glass silk, FEP, PFA, ETFE, silicone, or with insulation made of insulating varnish, in particular made of autoclavable material, e.g. polyesterimide varnish, is used.

In particular, it is provided that the electrical line is provided as a winding wire for coils, transformers, relays and motors. Using the method according to the invention, these can then be attached to a circuit board in an advantageous manner, forming an autoclavable connection.

Preferably, the electrical line is provided in the form of a wire coil or wound into the form of a wire coil prior to arranging the conductor connection end at the connection region.

Particularly preferably, the electrical line is provided in the form of a self-supporting coil or wound into the form of a self-supporting coil before the conductor connection end is arranged in the connection area. It is preferably provided that an electrical line in the form of a baked enamel wire is used. This is a conductor with insulation made of baked enamel, having a temperature-resistant base insulation and a cover layer that bonds when heated. When the baked enamel wire is heated (baked), the individual turns of the coil are bonded to one another, which gives the coil mechanical strength and stability. According to one embodiment of the method, the coil is provided already baked or is only baked after winding to form the coil.

It has proven to be advantageous if a joining material is applied to the conductor cross-sectional area before arranging the conductor connection end at the connection area, in particular immediately after cutting or cutting the cable to length, or if the electrical cable is already provided with joining material on the conductor cross-sectional area. This prevents the conductor cross-sectional area from oxidizing. It also leads to a better connection of the conductor cross-sectional area to the connection area of the circuit board.

A solder or a conductive adhesive is advantageously applied as the joining material. Solder is particularly preferably applied, the conductor cross-sectional area is thus pre-tinned. The solder also advantageously reduces the soldering time when the conductor cross-sectional area is later connected to the connection area of the circuit board. The joining material for coating the conductor cross-sectional area is expediently matched to the joining material predetermined for connecting the conductor cross-sectional area to the connection area.

For arranging the conductor connection end on the connection area of the circuit board, according to a first alternative of the invention, the circuit board has at least one through hole in the connection area, which passes through the circuit board from a first circuit board side to a second circuit board side opposite it. When arranging the conductor connection end in the connection area, the conductor connection end is then inserted from the first circuit board side into the through hole and aligned essentially flush with the connection area provided on the second circuit board side. In particular, the conductor cross-sectional area to be contacted, provided on one end face of the conductor connection end, is aligned flush with the connection area provided on the second circuit board side.

Preferably, the through hole is designed as a through-plating, in particular such that the wall of the through-plating is coated with electrically conductive material, which merges into the material of the connection area on the second circuit board side and preferably merges into the material of a further connection area arranged around the through-plating on the first circuit board side. This enables a better connection of the conductor cross-sectional area to the circuit board.

It has proven to be particularly advantageous if the conductor connection end is inserted into the through hole, aligned with the connection area provided on the second side of the circuit board and held in this position. In this way, the joining material can be applied precisely in the subsequent step, resulting in a good connection between the conductor cross-sectional area and the connection area.

When applying the conductive joining material to the connection area of the circuit board and to the conductor connection end, a solder or an electrically conductive adhesive, in particular glue, is preferably applied so that the conductor cross-sectional area is soldered or glued to the connection area.

For soldering, it is preferable to use a hard solder, especially one with a silver or high silver content base. This creates an electrically conductive, temperature-resistant, autoclavable connection.

An electrically conductive adhesive (conductive glue) is preferably used as the adhesive. Conductive glue consists of an adhesive and electrically conductive, in particular metallic, fillers. Temperature-resistant conductive glue is preferably used, preferably based on epoxy resin or ceramic. Silver, gold, palladium or platinum, for example, is provided as the filler. This creates an electrically conductive, temperature-resistant, autoclavable connection.

When attaching the electrical cable to the circuit board, a potting compound is preferably used as a fastening agent. A potting compound made of epoxy resin, polyurethane, polyolefin, silicone or acrylate is preferably used.

Within the scope of an embodiment of the invention, it is preferably provided that the potting compound is applied from the first side of the circuit board. The through hole is thereby at least partially, in particular completely, filled with the potting compound. Preferably, at least the part of the electrical line arranged in the through hole is at least partially, in particular completely, encased.

It has proven to be advantageous if the potting compound is applied in such a way that it also envelops part of the line section protruding from the through-hole in the direction of the first circuit board side and/or is arranged on the first circuit board side on an edge region around the through-hole.

Particularly preferably, the potting compound is applied in such a way that the electrical line is encapsulated on the circuit board, in particular in the form of a protective sheath (glob top). It is also preferably provided that the potting compound is applied using a dispenser. This enables precise dosing in exactly the desired area.

The casting compound advantageously provides a flexible but stable fastening of the electrical cable, so that a mechanical load on the electrical cable is absorbed by the casting compound and not on the soldering or bonding point between the conductor cross-sectional areas. surface and connection area. This creates a permanent, stable and mechanically strong contact between the electrical cable and the connection area.

When arranging the conductor connection end on the connection area of the circuit board, according to one embodiment of the invention, the conductor connection end of the electrical line is arranged such that the conductor cross-sectional area of the conductor extends at an angle to the connection area. The angle is formed or defined by an imaginary plane parallel to the conductor cross-sectional area and an imaginary plane parallel to the surface of the connection area or the second circuit board side. The angle is preferably between 60° and 90°. It is preferred that the angle is approximately 90°, i.e. the conductor cross-sectional area is arranged essentially perpendicular to the connection area.

In this embodiment, it has proven advantageous if the circuit board has an electrically conductive contact surface for the conductor connection end formed in the connection area. When arranging the conductor connection end on the connection surface, the conductor connection end is then arranged at least partially adjacent to the contact surface. This makes it easier to arrange or position the conductor connection end on the connection surface and to apply the joining material. In addition, incorporating the contact surface into the joining material and/or the casting compound results in even better fastening.

The contact surface includes a coating or consists of a material that is easy to solder and/or bond, e.g. a preferably tinned copper alloy or hard silver-plated brass.

Preferably, the contact surface and/or the connection area comprises at least one profile behind which the casting compound can flow, which is enclosed during the subsequent application of the casting compound. This promotes the strength of the encapsulation.

When applying the joining material, it is preferably provided that the joining material is applied in a region between the connection region and the conductor cross-sectional area, in particular between the contact surface and the conductor cross-sectional area, so that the connection region and/or the contact surface is electrically connected to the conductor cross-sectional area.

Preferably, the joining material is applied in such a way that the connection area is completely covered with joining material, in particular that the contact surface is at least partially, in particular completely, enclosed by the joining material.

When applying the potting compound, it is preferably provided that the potting compound is applied to the joining material applied in the connection area and at least part of the electrical line. It is particularly provided that the potting compound completely encapsulates the joining material.

• - Bereitstellen der elektrischen Leitung,
• - Wickeln der elektrischen Leitung zu einer Spule,
• - Verdrillen der elektrischen Leitung,
• - Ablängen der elektrischen Leitung am zu kontaktierenden Leiteranschlussende,
• - Vorverzinnen des Leiterquerschnitts am Leiteranschlussende,
• - Backen der elektrischen Leitung bzw. der Spule,
• - Anordnen des Leiteranschlussendes am Anschlussbereich der Leiterplatte,
• - Applizieren des Fügematerials an den Anschlussbereich der Leiterplatte und an das Leiteranschlussende und
• - Befestigen der elektrischen Leitung an der Leiterplatte mit Vergussmasse.

A particularly preferred embodiment comprises the following method steps, whereby the features described above are implemented in detail:

• - Providing the electrical cable,
• - Winding the electrical cable into a coil,
• - Twisting the electrical cable,
• - Cutting the electrical cable to length at the conductor connection end to be contacted,
• - Pre-tinning of the conductor cross-section at the conductor connection end,
• - Jaws of the electrical cable or coil,
• - Arranging the conductor connection end at the connection area of the circuit board,
• - Applying the joining material to the connection area of the circuit board and to the conductor connection end and
• - Fasten the electrical cable to the circuit board with potting compound.

As explained, the method according to the invention has the advantage that the electrical contact is advantageously made exclusively via the front-side conductor cross-sectional area. In the context of the invention, it was surprisingly discovered that this achieves good contact and that an overall stable and permanent connection is provided by means of the additionally applied casting compound.

The above object is further achieved by a circuit board according to claim 10. According to the generic type, the circuit board has at least one autoclavable electrical connection between an electrical line and an electrically conductive connection region of the circuit board, wherein the electrical line has at least one conductor and an insulation radially surrounding the conductor.

The solution according to the invention is that the insulation of the electrical cable extends to the conductor connection end, so that the conductor with a conductor cross-sectional area formed on the front side at the conductor connection end is electrically connected to the connection area of the circuit board via a conductive joining material. In addition, the electrical line is at least indirectly attached to the circuit board with a fastening means.

The advantage of this solution is that the electrical connection is only made via contact with the conductor cross-sectional area at the end of the conductor connection end, and the mechanical stability essentially results from the fastening means. The circuit board is therefore simple in design and easy to manufacture, without the need for a stripped conductor connection end. This is particularly advantageous for autoclavable cables, as these have insulation that can only be stripped with great effort.

According to a preferred embodiment of the circuit board, the autoclavable electrical connection is produced according to the method described above.

The circuit board is preferably a circuit carrier made of fiber-reinforced plastic, e.g. FR4, or a circuit carrier made of ceramic, e.g. aluminum oxide, aluminum nitride, silicon carbide, beryllium oxide or boron nitride.

The connection area provided on the circuit board for connection to the conductor connection end is preferably designed as a solder pad or a through-hole with an electrically conductive coating.

The electrical cable is preferably a stranded wire with several stranded wires, each with insulation, or an insulated single wire. The stranded wires or the single wire are preferably made of copper, copper alloys, aluminum or silver.

The insulation is preferably an insulating varnish, in particular made of autoclavable material, e.g. polyester imide varnish. It is advantageously provided that an individual wire has insulation in the form of an insulating sleeve, in particular made of autoclavable material, e.g. glass silk, FEP, PFA, ETFE, silicone. In particular, it is provided that the electrical line is a winding wire for coils, transformers, relays and motors. The electrical line is particularly preferably a wire coil, in particular a self-supporting coil made of baked enamel wire.

It has been found to be advantageous if the conductor cross-sectional area is coated with a joining material that protects the conductor material against oxidation and promotes the creation of an electrical contact. This is preferably a coating with solder, in particular a pre-tinning, or a coating with conductive adhesive.

The electrically conductive joining material, via which the conductor cross-sectional area is connected to the connection area of the circuit board, is preferably a solder, preferably a hard solder, in particular based on silver or high silver content, or an adhesive, preferably an electrically conductive adhesive (conductive adhesive), in particular based on epoxy resin or ceramic with metallic fillers, e.g. silver, gold, palladium or platinum.

The fastening means with which the electrical cable is attached to the circuit board is preferably a potting compound, preferably made of epoxy resin, polyurethane, polyolefin, silicone or acrylate.

According to one embodiment of the circuit board according to the invention, it is provided that the circuit board has at least one through hole in the connection area, which passes through the circuit board from a first circuit board side to a second circuit board side. The conductor connection end is introduced into the through hole from the first circuit board side and is aligned substantially flush with the connection area provided on the second circuit board side. In particular, the conductor cross-sectional area provided on the front side at the conductor connection end is aligned flush with the connection area provided on the second circuit board side.

The through hole is preferably designed as a known through-plating. The through-plating preferably has a contact coating extending from the first circuit board side through the hole in the through-plating to the second circuit board side. In particular, the contact coating comprises the connection area on the second circuit board side, a connection area provided on the wall of the through-plating and a further connection area arranged on the first circuit board side. The two connection areas on the first and second circuit board sides are arranged, for example, in a ring shape, in particular concentrically, around the through hole.

The conductive joining material is applied at least partially, in particular completely, to the connection area and to the conductor cross-sectional area arranged in the connection area. As a result, the conductor cross-sectional area is connected to the Connection area electrically and materially connected.

It is advantageously provided that the conductive joining material extends at least partially into the through-hole and/or, in the case of several lines arranged in the through-hole, also between the lines.

It is further provided that the fastening means, in particular the potting compound, is arranged on the first side of the circuit board. When using a potting compound, at least the through hole is at least partially, in particular completely, filled, advantageously in such a way that the electrical line is at least partially covered and at least part of the first side of the circuit board is encapsulated in an edge area around the through hole. This results in a flexible but firm fastening of the line to the circuit board, so that a mechanical load on the electrical line is absorbed by the potting compound and does not act on the soldering or adhesive point between the conductor cross-sectional area and the connection area. This results in a permanent, stable and mechanically strong contact between the electrical line and the connection area.

It is advantageous if the potting compound completely envelops the electrical line located in the through-hole and also a part of the line emerging from the through-hole on the first side of the circuit board and is arranged on the first side of the circuit board in the edge area around the through-hole.

According to a further embodiment of the circuit board according to the invention, it is provided that the conductor connection end of the electrical line is arranged in the connection area of the circuit board in such a way that the conductor cross-sectional area of the conductor extends at an angle to the connection area. The angle is defined by an imaginary plane parallel to the conductor cross-sectional area or which contains the conductor cross-sectional area, and an imaginary plane parallel to the surface of the connection area or a circuit board top. The angle is preferably between 60° and 90°. It is preferred that the angle is approximately 90°, i.e. the conductor cross-sectional area is essentially perpendicular to the connection area.

In this embodiment, it has proven advantageous if the circuit board has an electrically conductive contact surface formed in the connection area, wherein the conductor connection end is arranged at least partially adjacent to the contact surface.

The contact surface comprises a coating or is made of a material that is easy to solder and/or bond, e.g. a preferably tinned copper alloy or hard silver-plated brass.

Preferably, the contact surface and/or the connection area comprises at least one flowable profile which is enclosed by the potting compound. This promotes the strength of the encapsulation.

Preferably, the joining material is arranged in a region between the connection region and the conductor cross-sectional area, in particular between the contact surface and the conductor cross-sectional area, so that the connection region and/or the contact surface is electrically connected to the conductor cross-sectional area.

Preferably, the connection area is completely covered with joining material, in particular the contact surface is at least partially, in particular completely, enclosed by the joining material.

Preferably, the potting compound is applied to the joining material applied in the connection area and to at least part of the electrical line. It is particularly intended that the potting compound completely encapsulates the joining material.

The object mentioned at the outset is further achieved by an autoclavable electronic component according to claim 15.

According to the generic type, the electronic component has at least one electrical component. The electrical component has at least one electrical line, each having at least one conductor connection end, with at least one conductor and an insulation radially surrounding the conductor. An electrical connection is formed between a conductor connection end of the electrical line and a connection area of a circuit board. It is preferably provided that a plurality of lines are present.

The solution according to the invention consists in that the connection between the conductor connection end of the electrical line and the connection area of the circuit board is produced by the method described above and/or is a connection on a circuit board according to the above description.

Preferably, the electronic component is an electric drive, preferably an electric motor, in particular a direct current motor.

Preferably, the electronic component has at least two components in the form of a coil, each of which is formed from at least one electrical line.

• 1a ein Ausführungsbeispiel einer im Rahmen der Erfindung verwendbaren elektrischen Leitung,
• 1b ein Ausführungsbeispiel einer im Rahmen der Erfindung verwendbaren elektrischen Leitung,
• 2 die Positionierung der elektrischen Leitung in Bezug zur Leiterplatte gemäß einem ersten Ausführungsbeispiel der Erfindung,
• 3 eine elektrische Verbindung gemäß dem ersten Ausführungsbeispiel der Erfindung,
• 4 die Positionierung der elektrischen Leitung in Bezug zur Leiterplatte gemäß einem zweiten Ausführungsbeispiel der Erfindung,
• 5 eine elektrische Verbindung gemäß dem zweiten Ausführungsbeispiel der Erfindung,
• 6 eine elektrische Verbindung gemäß dem zweiten Ausführungsbeispiel der Erfindung, und
• 7 eine schematische Darstellung eines Ausführungsbeispiels des Verfahrens.

Further advantageous embodiments of the invention emerge from the following description of the figures and the dependent subclaims. They show:

• 1a an embodiment of an electrical cable usable within the scope of the invention,
• 1b an embodiment of an electrical cable usable within the scope of the invention,
• 2 the positioning of the electrical line in relation to the circuit board according to a first embodiment of the invention,
• 3 an electrical connection according to the first embodiment of the invention,
• 4 the positioning of the electrical line in relation to the circuit board according to a second embodiment of the invention,
• 5 an electrical connection according to the second embodiment of the invention,
• 6 an electrical connection according to the second embodiment of the invention, and
• 7 a schematic representation of an embodiment of the method.

In the various figures of the drawing, identical parts are always provided with the same reference symbols.

With regard to the following description, it is claimed that the invention is not limited to the embodiments and thereby not to all or several features of described feature combinations, but rather each individual partial feature of the/each embodiment is also detached from all other partial features described in connection with it, in itself and also in combination with any features of another embodiment of importance for the subject matter of the invention.

In 1a and 1b an advantageous electrical line 1 that can be used within the scope of the invention is shown. The electrical line 1 is designed as a strand 2 with several stranded wires 3, each of which has an insulation 4. For reasons of clarity, only three stranded wires 3 are shown. The stranded wires 3 are twisted together in a manner known per se.

Preferably, the stranded wire 2 is a winding wire for a coil. It is within the scope of the invention that the stranded wire 2 is formed into a coil or is designed as a coil (not shown).

The stranded wire 3 has a free conductor connection end 3a and a conductor cross-sectional area 3b formed on the front side of the conductor connection end 3a. The conductor cross-sectional area 3b is preferably covered with a joining material 5 ( 1 b) coated, e.g. pre-tinned with solder, to protect the conductor material against oxidation and improve solderability. The stranded wire 3 consists e.g. of copper, copper alloys, aluminum or silver. The insulation 4 is arranged radially around the stranded wire 3 and extends to the conductor connection end 3a. The insulation 4 is expediently flush with the stranded wire 3 or the conductor cross-sectional area 3b at the conductor connection end 3a. The insulation 4 is autoclavable. The insulation 4 is preferably a temperature-resistant insulating varnish, in particular baking varnish. In particular, the insulation 4 is designed such that it can be removed by dipping in caustic soda solution (caustic soda process).

In 2 the arrangement of the electrical line 1 on a circuit board 6 according to a first embodiment of the invention is shown. The circuit board 6 has a first circuit board side 6a, a second circuit board side 6b opposite this and a connection area 7.

The connection area 7 is designed as a through-plating 8, having a through hole 9 passing from the first circuit board side 6a to the second circuit board side 6b and an electrically conductive, metallic contact coating 10.

The contact coating 10 extends from the first circuit board side 6a through the through hole 9 to the second circuit board side 6b. The contact coating 10 forms on the first and second circuit board sides 6a, 6b a connection field 10a, 10b arranged in a ring shape, in particular concentrically, around the through hole 9 and a tubular connection field 10c lining the inner wall of the through hole 9. The circuit board 6 is preferably a circuit carrier substrate made of fiber-reinforced plastic, e.g. FR4.

In order to contact the electrical line 1 with the connection area 7 of the circuit board 6, it is provided that the conductor connection end 3a of the electrical line 1 is introduced from the first circuit board side 6a into the through hole 9 and is essentially flush with the connection area 7 provided on the second circuit board side 6b. or connection field 10a. In particular, the conductor cross-sectional area 3b provided on the front side of the conductor connection end 3a is aligned with the connection field 10a formed on the second circuit board side 6b.

In 3 a printed circuit board 6 with an electrical connection 11 according to the first embodiment of the invention is shown. The printed circuit board 6 is as 2 described and has the electrical line 1 arranged in the through-hole 8, the conductor connection end 3a of which is aligned with the connection field 10a.

The electrical connection 11 according to the invention comprises an electrically conductive joining material 12 and a fastening means 13, here in the form of a potting compound 14.

The joining material 12 is applied to the connection area 7 or the connection field 10b and to the conductor cross-sectional area 3b of the respective stranded wires 3 of the electrical line 1 arranged in the through hole 9, which is aligned therewith. The joining material 12 advantageously covers the connection field 10b completely. In addition, the joining material 12 extends partially into the through hole 9 and between the individual insulated stranded wires 3, which promotes the strength of the electrical connection 11. As a result, the conductor cross-sectional area 3b is electrically and materially connected to the connection area 7.

The joining material 12 is a solder, preferably a hard solder, in particular based on silver or a high silver content. However, it is within the scope of the invention that the joining material 12 is a conductive adhesive.

The potting compound 14 is applied to the first circuit board side 6a, the through hole 9 being completely filled and the electrical line 1, in particular the individual insulated stranded wires 3, being covered with the potting compound 14. The potting compound 14 is therefore arranged between the individual insulated stranded wires 3 and between the stranded wires 3 and the wall of the through hole 9. The potting compound 14 expediently also extends to a certain area of the electrical line 1 emerging from the through hole 9 on the first circuit board side 6a, so that the line 1 or the individual line wires 3 are also covered with potting compound 14 in this area. This also has the effect of improving strength. The potting compound 14 is also preferably arranged at least partially on the first circuit board side 6a in the edge area around the through hole 9, i.e. on the connection field 10b.

The connection 11 according to the invention thus brings about an electrical contacting of the electrical line 1 by the joining material 12 in combination with a firm encapsulation of the electrical line 1 by the potting compound 14. As a result, a mechanical load on the electrical line 1 can be absorbed by the potting compound and damage to the contact can be avoided.

The potting compound 14 is preferably epoxy resin, polyurethane, polyolefin, silicone or acrylate.

In 4 the arrangement of the electrical line 1 on a circuit board 6 is shown according to a second embodiment of the invention. The circuit board 6 has a first circuit board side 6a, a second circuit board side 6b opposite this and at least one connection area 7 and preferably at least one electrically conductive contact element 15 formed in the connection area 7.

The connection region 7 is formed on the second circuit board side 6b as a flat, electrically conductive, metallic contact coating 10, in particular as a solder pad.

The contact element 15 protrudes from the circuit board 6, in particular perpendicularly, and has a contact surface 15a which is arranged at an angle, in particular perpendicularly, to the second circuit board side 6a. The circuit board 6 is preferably a circuit carrier substrate made of fiber-reinforced plastic, e.g. FR4.

To contact the electrical line 1 at the connection area 7, the conductor connection end 3a of the electrical line 1 or of the respective stranded wire 3 is arranged on the contact coating 10 of the connection area 7, so that the conductor cross-sectional area 3b of the respective conductor 3 extends at an angle α to the connection area 7. The angle α is defined as an angle between an (imaginary) plane parallel to the conductor cross-sectional area 3b and an (imaginary) plane parallel to a connection area top 7a. The angle α is preferably between 60° and 90°. The angle α is preferably approximately 90°, so that the conductor cross-sectional area 3b is arranged essentially perpendicular to the connection area top 7a.

Preferably, the conductor connection end 3a is arranged at least partially adjacent to the contact surface 15a. In particular, the conductor cross-sectional area 3b of the individual stranded wires 3 provided on the front side of the conductor connection end 3a is arranged adjacent to the contact surface 15a. net. The use of the contact element 15 or the contact surface 15a is advantageous, but not absolutely necessary.

In 5 a circuit board 6 with an electrical connection 11 according to the second embodiment of the invention is shown. The circuit board 6 is as shown in 4 described, wherein the electrical line 1 is arranged at an angle α on the connection area 7. The electrical connection 11 according to the invention comprises an electrically conductive joining material 12 and a fastening means 13, here in the form of a casting compound 14.

The joining material 12 is arranged in a region between the contact coating 10 of the connection region 7 and the conductor cross-sectional area 3b, in particular between the contact surface 15a and the conductor cross-sectional area 3b, so that the connection region 7 and/or the contact surface 15a is electrically connected to the conductor cross-sectional area 3b.

Advantageously, the connection region 7 is completely covered with joining material 12, in particular the contact surface 15a is completely enclosed 12.

The joining material 12 is a solder, preferably a hard solder, in particular based on silver or a high silver content. However, it is within the scope of the invention that the joining material 12 is a conductive adhesive.

The potting compound 14 is applied to the second circuit board side 6b. The potting compound 14 preferably completely covers or envelops the applied joining material 12. The potting compound 14 is expediently applied at least partially in an area of the second circuit board side 6b around the connection area 7.

The connection 11 according to the invention thus brings about an electrical contact of the electrical line 1 by the joining material 12 in combination with a firm encapsulation of the electrical line 1 by the casting compound 14. As a result, a mechanical load on the electrical line 1 can be absorbed by the casting compound and damage to the contact can be avoided. The casting compound is preferably epoxy resin, polyurethane, polyolefin, silicone or acrylate.

6 shows a circuit board 6 with an electrical connection 11 according to the second embodiment of the invention. The circuit board 6 is as shown in 4 or. 5 described, wherein the electrical line 1 is arranged at an angle α on the connection area 7. The electrical connection 11 according to the invention comprises an electrically conductive joining material 12 and a fastening means 13, here in the form of a casting compound 14.

The joining material 12 is arranged in a region between the contact coating 10 of the connection region 7 and the conductor cross-sectional area 3b, so that the connection region 7 is electrically connected to the conductor cross-sectional area 3b. In comparison to the embodiment of the 5 In this version, the contact element 15 is omitted.

7 shows an embodiment of a schematic sequence of a method 100 according to the invention. The method 100 comprises the following method steps: providing 101 the electrical line 1, wherein the insulation 4 extends to at least one conductor connection end 3a, so that the conductor 3 can be contacted at a conductor cross-sectional area 3b formed on the front side of the conductor connection end 3a. The insulation 4 preferably extends to the conductor connection end 3a in such a way that the conductor 3 can only be contacted via the front side conductor cross-sectional area 3b. The insulation 4 extends in particular in such a way that it extends into an imaginary plane in which the front side conductor cross-sectional area 3b is also arranged.

The method preferably comprises the application 101a of a joining material 5, in particular a solder, to the conductor cross-sectional area 3b formed at the conductor connection end 3a. This can take place before or after the provision 101 of the line 1. The line 1 is preferably cut to a predetermined length before the application 101a of the joining material 5.

Subsequently, the arrangement 102 of the conductor connection end 3a on the connection region 7 of the circuit board 6 takes place. This is done, for example, as described above in such a way that the front-side conductor connection surface 3b is arranged substantially parallel to a surface of the second circuit board side 6b or substantially perpendicular to a surface of the second circuit board side 6b of the circuit board 6.

Furthermore, the application 103 of a conductive joining material 12 to the connection region 7 of the circuit board 6 and to the conductor connection end 3a takes place, so that a material-locking, electrically conductive connection is produced between the material of the connection region 7 and the conductor cross-sectional area 3a, in particular the joining material 5.

Finally, the cable 1 is secured 104 with at least one fastening means 13 at least indirectly to the circuit board 6. Preferably, a potting compound 14 is used as the fastening means 13.

The invention is not limited to the exemplary embodiments shown and described, but also includes all embodiments that have the same effect within the meaning of the invention. It is expressly emphasized that the exemplary embodiments are not limited to all features in combination; rather, each individual partial feature can also have an inventive significance in itself, separated from all other partial features. Furthermore, the invention is not yet limited to the combination of features defined in the claims, but can also be defined by any other combination of specific features of all the individual features disclosed overall. This means that in principle practically every individual feature of the independent claim can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.

Reference symbols

1

Electrical line

2

Strand

3

Conductor (stranded wire)

3a

Conductor connection end

3b

Conductor cross-sectional area

4

insulation

5

Joining material

6

Circuit board

6a

first PCB side

6b

second circuit board side

7

Connection area

7a

Connection area top

8th

Through-hole plating

9

Through hole

10

Contact coating

10a

Connection panel

10b

Connection panel

10c

Connection panel

11

electrical connection

12

Joining material

13

Fasteners

14

Casting compound

15

Investment element

15a

Contact surface

100

Proceedings

101

Provide

101a

Apply

102

Arrange

103

Apply

104

Fasten

α

angle

Claims (15)

Method (100) for producing an autoclavable electrical connection (11) between at least one conductor connection end (3a) of an electrical line (1) and at least one electrically conductively coated connection area (7) on a circuit board (6), wherein the electrical line (1) has at least one conductor (3) and an insulation (4) radially surrounding the conductor (3), characterized in that the method (100) comprises the following method steps - providing (101) the electrical line (1), wherein the insulation (4) extends to at least one conductor connection end (3a), so that the conductor (3) can be contacted on a conductor cross-sectional area (3b) formed on the front side of the conductor connection end (3a), - arranging (102) the conductor connection end (3a) on the connection area (7) of the circuit board (6), - applying (103) a conductive joining material (12) to the connection area (7) of the circuit board (6) and to the conductor connection end (3a), so that a material-locking, electrically conductive connection is established between the material of the connection region (7) and the conductor cross-sectional area (3b), - fastening (104) the line (1) with at least one fastening means (13) at least indirectly to the circuit board (6). Procedure (100) according to Claim 1 , characterized in that the fastening means (13) is a casting compound (14), and that the line (1) is additionally fastened to the circuit board (6), at least in the region of the conductor connection end (3a). Method (100) according to one of the preceding claims, characterized in that the line (1) is a stranded wire (2) with several conductors (3) in the form of stranded wires, each having a separate insulation (4). Method (100) according to one of the preceding claims, characterized in that the line (1) is provided in the form of a wire coil or before arranging the conductor connection (3a) is wound into the form of a wire coil at the connection area (7). Method (100) according to one of the preceding claims, characterized in that before arranging the conductor connection end (3a) on the connection region (7), a joining material (5) is applied to the conductor cross-sectional area (3b) or that the line (1) is provided with joining material (5) on the conductor cross-sectional area (3b). Method (100) according to one of the preceding claims, characterized in that the circuit board (6) has at least one through hole (9) in the connection area (7), that the through hole (9) passes through the circuit board (6) from a first circuit board side (6a) to a second circuit board side (6b), and that the conductor connection end (3a) is inserted into the through hole (9) from the first circuit board side (6a) into the connection area (7) when arranging the conductor connection end (3a) in the connection area (7) and is aligned substantially flush with the connection area (7) provided on the second circuit board side (6b). Procedure (100) according to Claim 2 and 6 , characterized in that the potting compound (14) is applied from the first circuit board side (6a), wherein at least the through hole (9) is at least partially, in particular completely, filled, advantageously such that the line (1) is at least partially encased and in particular at least a part of the first circuit board side (6a) is encapsulated in an edge region around the through hole (9). Method (100) according to one of the Claims 1 until 5 , characterized in that when arranging the conductor connection end (3a) on the connection region (7), the conductor connection end (3a) is arranged such that the conductor cross-sectional area (3b) of the conductor (3) extends at an angle (α), preferably between 60° and 90°, to the connection region (7). Procedure (100) according to Claim 8 , characterized in that the circuit board (6) is provided with an electrically conductive contact surface (15a) formed in the connection region (7), wherein the conductor connection end (3a) is arranged at least partially adjacent to the contact surface (15a). Printed circuit board (6) with at least one autoclavable electrical connection (1), preferably produced using a method (100) according to one of the preceding claims, between an electrical line (1) and an electrically conductive connection region (7) of the printed circuit board (6), wherein the electrical line (1) has at least one conductor (3) and an insulation (4) radially surrounding the conductor (3), characterized in that the insulation (4) extends to the conductor connection end (3a), so that the conductor (3) is electrically conductively connected to the connection region (7) of the printed circuit board (6) via a conductive joining material (12) with a conductor cross-sectional area (3b) formed on the front side at the conductor connection end (3a), and that the line (1) is at least indirectly attached to the printed circuit board (6) with a fastening means (13). Printed circuit board (6) after Claim 10 , characterized in that the fastening means (13) is a casting compound (14). Printed circuit board (6) according to one of the Claims 10 until 11 , characterized in that the circuit board (6) has at least one through-hole (9) in the connection area (7), that the through-hole (9) passes through the circuit board (6) from a first circuit board side (6a) to a second circuit board side (6b), and that the conductor connection end (3a) is inserted from the first circuit board side (6a) into the through-hole (9) and is aligned substantially flush with the connection area (7) provided on the second circuit board side (6b). Printed circuit board (6) after Claim 11 and 12 , characterized in that the potting compound (14) is applied to the first circuit board side (6a), wherein at least the through hole (9) is at least partially, in particular completely, filled, advantageously such that the line (1) is at least partially encased and at least a part of the first circuit board side (6a) is encapsulated in an edge region around the through hole (9). Printed circuit board (6) according to one of the Claims 10 until 11 , characterized in that the conductor connection end (3a) is arranged in the connection region (7) such that the conductor cross-sectional area (3b) of the conductor (3) extends at an angle (α), preferably between 60° and 90°, to the connection region (7). Autoclavable electronic component, in particular an electric drive, preferably a direct current motor, comprising at least one electrical component, wherein the electrical component comprises at least one electrical line (1) having at least one conductor connection end (3a) with at least one conductor (3) and an insulation (4) radially surrounding the conductor (3), wherein an electrical connection (11) is formed between a conductor connection end (3a) of the electrical line (1) and a connection region (7) of a printed circuit board (6), characterized in that the connection (11) by a method (100) according to one of the Claims 1 until 9 and/or as a connection (11) on a printed circuit board (6) according to one of the Claims 10 until 14 is trained.

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