EP-4736585-A1 - METHOD FOR ESTABLISHING AN ELECTRICAL CONNECTION BETWEEN A PRINTED CIRCUIT BOARD AND A CONNECTION WIRE, AND ELECTROHYDRAULIC ACTUATOR

Abstract

The invention relates to a method for establishing an electrical connection between a printed circuit board (1) and a connection wire (2), wherein the printed circuit board (1) is provided with a metallization area (11), the method comprising the following steps: - providing a housing part (7), which is provided with a wall (72) and at least one projection (75) projecting in relation to the wall (72), - applying a material deposit (16) composed of an electrically conductive paste (17) to the wall (72) of the housing part (7) in a locally limited region (74) outside the projection (75), - placing a portion (21) of the connection wire (2) onto the material deposit (16), wherein the portion (21) of the connection wire (2), by way of its outer sheath (22), adheres to the material deposit (16), - mounting the printed circuit board (1) onto the housing part (7) in such a way that the metallization area (11) of the printed circuit board (1) faces the portion (21) of the connection wire (2), and - pressing the printed circuit board (1) in the direction of the wall (72) of the housing part (7) until the printed circuit board (1) comes into contact with the projection (75), wherein the portion (21) of the connection wire (2) is pushed into the material deposit (16) by the metallization area (11), until the electrically conductive paste (17) of the material deposit (16) covers the metallization area (11) of the printed circuit board (1).

Inventors

• Komar, Nandor
• Varga, Eszter
• POZSEGA, Peter
• Hittaller, Adam

Assignees

• Robert Bosch GmbH

Dates

Publication Date

20260506

Application Date

20240621

Claims (1)

1. claims 1. Method for producing an electrical connection between a printed circuit board (1) and a connecting wire (2), wherein the printed circuit board (1) is provided with a metallization surface (11) on at least a first side (31), characterized by the following steps: Providing a housing part (7) which is provided with a wall (72) and at least one projection (75) protruding from the wall (72), Applying a material coating (16) of an electrically conductive paste (17) in a locally limited area (74) outside the projection (75) onto the wall (72) of the housing part (7), Placing a section (21) of the connecting wire (2) on the material deposit (16), wherein the section (21) of the connecting wire (2) adheres to the material deposit (16) with its outer sheath (22), Placing the printed circuit board (1) on the housing part (7) such that the metallization surface (11) of the printed circuit board (1) faces the section (21) of the connecting wire (2) and Pressing the circuit board (1) in the direction of the wall (72) of the housing part (7) until the circuit board (1) comes to rest with the first side (31) on the projection (75), wherein the section (21) of the connecting wire (2) is pressed from the metallization surface (11) into the material application (16) until the electrically conductive paste (17) of the material application (16) covers the metallization surface (11) of the circuit board (1) 2. Method according to claim 1, characterized in that the electrically conductive paste (17) comprises an electrically conductive adhesive. 3. Method according to claim 1 or 2, characterized in that the connecting wire (2) is a connecting wire of a coil winding (23) 4. Method according to one of the preceding claims, characterized in that the section (21) of the connecting wire (2) is circular in cross section. 5. Method according to one of the preceding claims, characterized in that the section (21) of the connecting wire (2) is pressed so deeply into the material deposit (16) that it is completely or almost completely embedded therein. 6. Method according to one of the preceding claims, characterized in that the circuit board (1) is fastened to the housing part (7) by fastening means (18) after the step of pressing the circuit board (1) onto the projection (75). 7. Method according to one of the preceding claims, characterized in that the method for producing an electrical connection between a metallization surface (11) on a circuit board (1) intended for installation on or in an electrohydraulic actuator (3) and at least one connecting wire (2) of a coil winding (23) of an electromagnet (51) of the electro-hydraulic actuator (3). 8. Electrohydraulic actuator (3) comprising a valve part (6), an electromagnet (5) with a coil winding (23), a magnet armature (52) movably mounted in the electromagnet (5) and a (52) actuated valve member (61) arranged in the valve part (6), characterized in that the electrohydraulic actuator (3) has at least one circuit board (1) which is arranged on a wall (72) of a housing part (7) on at least one projection (75) protruding from the wall (72), wherein the housing part (7) is arranged on an actuator housing (54) of the actuator, wherein at least one connecting wire (2) of the coil winding (23) is electrically conductively connected to a metallization surface (11) of the circuit board (1) by means of a material application (16) made of an electrically conductive paste (17) arranged between the wall (72) of the housing part (7) and the metallization surface (11) and covering the metallization surface (11).

Description

Description title Method for establishing an electrical connection between a printed circuit board and a connecting wire and electrohydraulic actuator State of the art In the prior art, for example, electrohydraulic actuators are used for controlling hydraulic systems that have an electromagnet with a magnetic coil and a valve part with a valve element. The valve element actuated by the electromagnet can open or close various inlet and outlet openings on the valve part and thereby adjust the pressure on one or more hydraulic consumers or a pressure channel. Such electrohydraulic actuators can be controlled via a control unit that adjusts the electrical current through the magnetic coil of the electromagnet. In the prior art, electrohydraulic control devices are used to control the electrohydraulic actuators. These are used, for example, in the transmission in automotive engineering and are generally designed as complex electronic modules with pressure sensors, speed sensors and other functions and can be used to control several electrohydraulic actuators. For example, DE 101 30 833 B4 discloses an electrohydraulic control device that has a hydraulic block with hydraulic channels and a component side. Several electrohydraulic actuators are arranged on the hydraulic block, each of which engages a receiving opening in the hydraulic block with a valve section from the component side. An electronic control unit comprises a circuit board designed as a large-area connection insulation layer with conductor tracks embedded in it. A central section of this circuit board functions as Circuit carrier and is equipped with the electronic components of a control circuit, which are covered with a cover part placed on the circuit board. The circuit board is led outwards laterally over the cover part and has electrical contact means on its edges, each of which is electrically contacted with the electrical connections of an electrohydraulic actuator. In the known solutions, all actuators are usually controlled via a common electronic control unit (ECU), which can determine the required actuating currents for the actuators, for example via a microprocessor, and provides the actuating currents for the actuators' electromagnets via output stage modules integrated into the control unit. The ECU has several output stages, so that several actuators can be controlled via this ECU. New developments and fields of application require that the electrohydraulic actuators are no longer operated via an output stage module in a central control unit, but are preferably addressed via a BUS system (e.g. CAN or LIN). However, the actuating current required to generate the actuating forces must then be generated in or on the actuator from a battery voltage. There is therefore a need for hydraulic actuators (so-called "smart actuators") that can be installed into a small, flexibly usable unit with an electronic control unit arranged directly in or on the actuator and assigned to the actuator. This raises the fundamental problem of how a coil winding of an actuator electromagnet is to be electrically connected to the control unit's circuit board. The coil winding of an electromagnet has a very thin wire that is rather slack. Mounting the connecting wire in the through-hole mounting known for circuit boards in a contact opening of the circuit board, similar to the conventional electronic wire components mounted on the circuit board, is therefore usually not possible or only possible with a high level of additional technical effort. Known electrical connection techniques between the connecting wires of the coil winding of an electromagnet and a circuit board therefore use intermediate connection means to achieve reliable contact. For example, DE 44 27 767 C2 shows a coil winding whose connecting wires are wound around the electromagnet's connector plug and are encapsulated in a plastic coil housing. The exposed ends of the connector plugs are led out of the coil housing as connector tabs. The stable connector tabs can be used for further contact with the circuit board, whereby additional contact elements can be inserted between the connector tabs and the circuit board. DE 103 37 197 B4, for example, discloses further contacting via contact elements designed as spring elements, which are contacted with the coil winding as part of the electromagnetic actuator. The spring contact elements can be pressed against a metallization surface on a circuit board with their ends facing away from the actuator. However, these solutions take up a lot of installation space. disclosure of the invention The invention relates to a method of electrical connection between a printed circuit board and a connecting wire, wherein the printed circuit board is provided with a metallization surface on at least a first side, characterized by the following steps: - providing a housing part which is provided with a wall and at least one projection protruding from the wall, - app