DE102021201099A1 - Mounting arrangement of a printed circuit board mounted component - Google Patents

Abstract

The invention relates to a fastening arrangement (1) for a component (2) mounted on a printed circuit board, in particular a choke coil or interference suppression choke, having a component (2) with at least one connection (8) and a printed circuit board (3) with at least one soldering surface (9) on which the connection (8) of the component (2) can be electrically contacted or soldered, with a recess (7) being introduced into the printed circuit board (3), in which the base body (4) of the component (2) is arranged, with its respective connection (8) is led out of the recess (7) for contacting with the soldering surface (9).

Description

The invention relates to a fastening arrangement for a circuit board-mounted component, in particular a choke coil or interference suppression choke, preferably electronics for an electric motor (motor electronics). It also relates to an electric motor of a motor vehicle, in particular a radiator fan motor, with such a fastening arrangement.

Electric motors of the type mentioned are used in various drive systems of a motor vehicle, in particular in the drive for a radiator fan (radiator fan drive or motor), but also, for example, in window regulators, seat adjusters, sunroofs or fans. Especially when used in motor vehicles, it is necessary to suppress interference from the electric motor, in particular to enable undisturbed radio reception (especially in the VHF range) and undisturbed operation of integrated control circuits or the like. The limitation of such radio interference to a permissible level is defined in standards.

Electric motors used in drives for actuating elements of a motor vehicle and operated with direct current can be electronically commutated and thereby be brushless or brushless and have a mechanical commutator whose commutator segments are connected to the armature windings of the rotor (rotor winding) and to brushes (carbon brushes) of a brush system make a sliding contact. As a result of a rotation of the motor shaft, the stator winding of the brushless electric motor and the rotor or armature winding of the brushless electric motor are usually supplied with current in the correct phase.

During operation with an electric motor, electromagnetic waves in the high-frequency range are generated by the electric motor and radiated into the environment. This leads to interference (radio interference) of technical devices in the vicinity of the electric motor, which contradicts the requirement for electromagnetic compatibility (EMC), namely to prevent such electromagnetic interference. In order to establish the EMC of such an electric motor, it is customary to equip the electronics of the electric motor (motor electronics) or the brush system with components for interference suppression (suppression elements).

As an alternative to or in combination with capacitors for damping high-frequency interference vibrations, suppression chokes (choke coils) are usually used as components for suppressing interference flows through the choke coil. Such an interference suppression choke for an electric motor usually has a coil core (iron core) on which an insulated electrical conductor is wound. The winding or coil ends of the conductor serve as connections (connection pins) for contacting the interference suppression choke, for example on a printed circuit board or circuit board (printed circuit board, PCB) of motor electronics.

In a brush-type electric motor with a brush system that has, for example, two brushes, each brush is usually assigned such a choke coil, each of which is connected to the motor connection (plus pole or minus pole) on the one hand and to the respective brush on the other hand. In the circuit closed via the commutator of the electric motor, the motor current, based on the technical current direction, flows from the positive pole of the motor voltage via a first choke coil (interference suppression choke) and via the two brushes grinding the commutator and then via the second choke coil (interference suppression choke) to the negative pole. pole of the motor voltage. Such an electric motor with a brush system and specially arranged interference suppression chokes is, for example, from DE 195 22 329 A1 and from the DE 93 16 543 U1 known.

In the case of a brushless (electronically commutated) electric motor, control is often carried out using what is known as pulse width modulation (PWM), in which square-wave electrical pulses (step signals) are generated with a predefined or definable pulse-pause ratio (duty cycle) in the kHz to MHz range , which, for example, simulate a sinusoidal drive characteristic of the electric motor as precisely as possible. Since the emission of electromagnetic waves is practically unavoidable in the area of the windings and the leads of the electric motor, which affect the electronics or other units and consumers in the vicinity of the electric motor, for example, reliable suppression of such electrical machines is required.

For example, from the DE 11 2009 002 657 T5 Known electric compressor with an electronics housing arranged therein (motor) electronics is connected to a coil component to eliminate electromagnetic interference, the coil component is attached to a printed circuit board of the motor electronics.

While in the so-called through-hole technology (THT) the connections (connection wires, connection pins) of Electrical or electronic components are guided through mounting holes in a printed circuit board and soldered on the back, this is not the case with surface-mounted components (surface mounted device, SMD). This not only makes it possible to equip the circuit board (board) on both sides, but also has a positive effect on the electrical properties of the circuits created, especially at higher frequencies.

Such SMD components are usually mounted on the printed circuit board in the so-called SMT process (surface-mounting technology) using automatic placement machines and soldering stations, in particular electrically contacted and mechanically fastened (equipped). The connection surfaces of the SMD components on the circuit board (printed circuit board, PCB) can be printed with solder or solder paste using the stencil printing process before assembly. After assembly, the SMD components are heat-soldered, with the reflow or soft-soldering process typically being used for assembly (assembly) on the top side of the printed circuit board or circuit board.

In the case of electric motors of actuator drives in a motor vehicle, too, the printed circuit board for the motor electronics, which is accommodated in a motor or electronics housing, is often equipped with such an SMT process. However, especially with round connections (connecting wires) of the components, their position alignment on the respective soldering pad (soldering pad, soldering surface) of the circuit board is problematic, which in turn can lead to further assembly problems of the motor electronics in the housing or on a heat sink.

During the SMT process, especially during reflow soldering, components or assemblies such as the choke coils or electrolytic capacitors used as interference suppression elements are often cooled. In this case, cooling takes place disadvantageously only on one side (mounting side) of the printed circuit board on which the respective component is mounted. There is also the disadvantage that the component to be mounted is displaced or tilted on the printed circuit board during the SMT process, in particular during reflow soldering, which leads to incorrect arrangement and/or attachment and thus to insufficient mounting of the component on the printed circuit board can lead.

The invention is therefore based on the object of specifying a particularly suitable fastening arrangement for an (electrical or electronic) component, in particular an interference suppression choke or choke coil, on a printed circuit board, preferably motor electronics of an electric motor.

This object is achieved according to the invention by the features of claim 1. Advantageous variants or configurations are the subject matter of the dependent claims (subclaims).

The mounting arrangement of a circuit board mounted component comprises an electrical or electronic component or component and a circuit board having a mounting side and a board back side opposite thereto. The component has a base body and at least one connection, preferably two connections. The printed circuit board has a solder pad, to which the connection of the component is electrically contacted or can be contacted, preferably soldered by means of the reflow process.

A recess is made in the printed circuit board, in which the base body of the component sits, with its respective connection being led out of the recess for contacting with and/or for contact with the soldering surface arranged in the region of an edge section, in particular on a narrow side, of the recess is. The recess can be window-like, in particular closed on the peripheral side. The recess can also be only partially closed on the peripheral side and, for example, be open on one side, in particular on a longitudinal side. The mounted component particularly expediently protrudes beyond the circuit board on the mounting side and on the back of the board normal to the plane of the circuit board.

The component is suitably a choke coil, the coil winding of which forms the base body and the coil ends of which form the respective connection of the component. Additionally or alternatively, the component can be a choke coil with a coil core (iron core), which forms the base body with the coil winding. Also, the device may be a two-terminal electrolytic capacitor. In the case of a choke coil as a component, its connections are routed out of the recess on opposite edge sides of the recess and there to a respective soldering surface of the printed circuit board. In the case of a capacitor as a component, its two connections are routed out of the window-like recess on the same side of the latter and there in each case to a soldering surface on the edge of the printed circuit board.

The connection of the component can have a round, in particular circular connection cross section. In particular, the connection is flattened to form at least one flat side. With this flat side, the connection of the component rests against or on the soldering surface.

According to an advantageous embodiment, the connection of the component has a connection section at the end, preferably bent at right angles. In this embodiment, an assembly opening assigned to the respective connection is provided in the printed circuit board, into which opening the bent connection section is inserted or can be inserted. The connection can be soldered to the mounting side of the printed circuit board, for which purpose the connection rests in sections on the mounting-side soldering surface or is in contact with this. The connection can also be soldered to the back of the board, for which purpose the or a corresponding soldering surface for soldering the inserted bent connection section is provided there in the area of the assembly opening. Such soldering areas for soldering the connection can also be provided on both sides of the printed circuit board.

The advantages achieved with the invention consist in particular in the fact that due to the arrangement of the component in the recess of the printed circuit board, the component can be cooled from both sides of the printed circuit board during the soldering process, in particular during the reflow process. In addition, the component is already securely positioned in the recess on the printed circuit board side, so that a shifting or tilting of the component during the SMT process is avoided or a corresponding risk is at least reduced. This can advantageously be improved by bending the respective connection and inserting it into a corresponding assembly opening in the printed circuit board. The fastening arrangement is particularly suitable and provided for an electric motor, in particular for a cooling fan motor of a motor vehicle.

• 1 in perspektivischer Darstellung eine erste Ausführung einer Befestigungsanordnung einer Drosselspule mit Spulenkern als elektrisches bzw. elektronisches Bauelement (Bauteil) auf einer Leiterplatte mit einer randseitig offenen Ausnehmung zur Aufnahme des Bauelements,
• 2 die Befestigungsanordnung gemäß 1 in teilweise geschnittener Seitenansicht,
• 3 in einer Draufsicht die Befestigungsanordnung mit einer umfangsseitig (randseitig) geschlossenen leiterplattenseitigen Ausnehmung, in welcher das Bauelement mit dessen Grundkörper einsitzt,
• 4 in perspektivischer Darstellung eine zweite Ausführung einer Befestigungsanordnung einer Drosselspule mit Spulenkern als elektrisches bzw. elektronisches Bauelement (Bauteil) auf einer Leiterplatte mit einer umfangsseitig (randseitig) geschlossenen Ausnehmung zur Aufnahme des Bauelements mit leiterplattenseitig durchgesteckten Anschlüssen, und
• 5 die Befestigungsanordnung gemäß 4 in teilweise geschnittener Seitenansicht.

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. Show in it:

• 1 a perspective view of a first embodiment of a fastening arrangement for a choke coil with a coil core as an electrical or electronic component (component) on a printed circuit board with a recess open at the edge to accommodate the component,
• 2 the mounting arrangement according to 1 in a partially sectioned side view,
• 3 in a top view, the fastening arrangement with a circuit board-side recess which is closed on the peripheral (edge) side and in which the component sits with its base body,
• 4 a perspective view of a second embodiment of a fastening arrangement for a choke coil with a coil core as an electrical or electronic component (component) on a printed circuit board with a recess closed on the peripheral (edge) side for receiving the component with connections pushed through on the printed circuit board side, and
• 5 the mounting arrangement according to 4 in a partially sectioned side view.

Corresponding parts are provided with the same reference symbols in all figures.

the 1 and 2 show an embodiment of a fastening arrangement 1 of a choke coil with a coil core as an electrical (electronic) component or part 2 on a printed circuit board 3 in a top view or in a partially sectioned side view or in a sectional view. The printed circuit board 3 has a top or mounting side 3a and opposite a plate back 3b ( 2 ) on. The component 2 has a base body 4 which is formed here by the coil core (iron core) 6 around which a coil or coil winding 5 is wound. The fastening arrangement 1 is particularly suitable for an electric motor, in particular for a cooling fan motor of a motor vehicle, with the component 2 being an interference suppression choke.

The circuit board 3 has a rectangular recess 7 in the exemplary embodiment for receiving the component 2, in which recess 7 the component 2 rests with its base body 4. In this variant, the circuit board-side recess 7 is closed on two narrow sides running in the y-direction and on a rear long side running in the x-direction, based on the arrow representation of the circuit board plane xy, while the front long side running in the x-direction of the recess is closed 7 in the area of a board edge of the printed circuit board 3 is open. The recess 7 on the printed circuit board is therefore only partially closed on the peripheral side here. However, the recess 7 for receiving the component 2 can be completely surrounded in the circumferential direction by the printed circuit board 3 or by the printed circuit board material.

Opposite connections 8 of the component 2 are led out of the circuit board-side recess 7, here on the two narrow sides running in the y-direction. On these opposite edge sides of the recess 7, the printed circuit board 3 has a solder pad 9 for making electrical contact with the respective connection 8 of the component 2 and for mechanically fastening it on the printed circuit board 3 by means of a solder. The connections 8 of the component 2 are flattened to form opposite flat sides 8a, 8b, the respective connection 8 in the exemplary embodiment having the flat side designated 8b on the corresponding soldering surface 9 is present. The soldering process is preferably carried out using the reflow method.

How out 2 As can be seen, the component 2 with its base body 4 projects beyond the printed circuit board 3 on its mounting side 3a and on its rear side 3b. The component 2 can thus be cooled from both sides during the soldering or reflow process. In addition, the structure or the overall thickness of the fastening arrangement 1 is smaller, at least by the thickness of the printed circuit board 3, than when the component 2 is mounted on the mounting side 3a of the printed circuit board 3 without a recess 7 on the printed circuit board. There is also a risk of pivoting, tilting or shifting of the component 2 is reduced during the assembly or fastening process, since the component 2 is already reliably positioned on or on the printed circuit board 3 by its arrangement in the recess.

In the variant according to the 3 until 5 the connection 8 of the component 2 has a connection section 10 bent at right angles at the end. An assembly opening 11 assigned to the respective connection 8 is provided in the printed circuit board 3 . The bent connection section 10 is inserted into this. This reliably prevents the component 2 from pivoting, tilting or shifting during the assembly or fastening process. The component 2 can therefore also be mounted securely on the printed circuit board 3 with a round, in particular circular, connection cross section. In addition, the component 2 is reliably positioned in its desired position even during the soldering or reflow process.

The terminal 8 can be soldered to the mounting side 3a of the circuit board 3, as shown in 3 is illustrated. Recognizable here is the recess 7 for receiving the component 2 in the circumferential direction, ie closed on the narrow sides and on the long sides. However, in this embodiment too, the recess 7 for accommodating the component 2 in the circumferential direction can only be partially enclosed by the printed circuit board 3 or by the printed circuit board material.

The connection 8 is preferably soldered to the back of the board 3b, as in 4 and in particular 5 is comparatively clear. For this purpose, one of the assembly openings 11 is provided adjacent to the recess 7, in the exemplary embodiment on the narrow sides running in the y-direction, through which the connection section 11 of the respective connection 8 passes. The corresponding soldering surface 9 for soldering the inserted bent connection section 11 surrounds the assembly opening 11 at least partially.

Due to the arrangement of the component 2 in the recess 7 of the printed circuit board 3, the component 2 can be cooled during the soldering process, in particular during the reflow process, on or from the mounting side 8a and the back of the board 8b. The component 2 is securely positioned in the circuit board-side recess 2 during the SMT process.

In summary, the invention relates to a fastening arrangement 1 of a circuit board-mounted component 2, in particular a choke coil, having a component 2 with at least one connection 8 and a circuit board 3 with at least one soldering surface 9, on or with which the connection 8 of the component 2 is soldered or welded or can be, wherein a recess 7 is provided in the printed circuit board 3, in which the component 2, in particular only with its base body 4, is seated.

The claimed invention is not limited to the embodiments described above. Rather, other variants of the invention can also be derived from this by the person skilled in the art within the scope of the disclosed claims without departing from the subject matter of the claimed invention. In particular, all of the individual features described in connection with the various exemplary embodiments can also be combined in other ways within the scope of the disclosed claims, without departing from the subject matter of the claimed invention.

The component 2 can also be an electrolytic capacitor with two terminals 8, for example. In this case, its two connections 8 are guided out of the recess 7 on the same side of the recess and there in each case on a soldering surface 9 of the printed circuit board 3, preferably on the edge.

In addition, the solution described can be used in various designs of motor vehicle applications, such as door and tailgate systems, window regulators, vehicle locks, adjustable seat and interior systems, and electric drives, controls, sensors and their arrangement in the vehicle .

Reference List

1

mounting arrangement

2

component/component

3

circuit board

3a

Panel top/mounting side

3b

plate back

4

body

5

coil/coil winding

6

iron/bobbin core

7

recess

8th

connection

8a, 8b

flat side

9

pad

10

connector section

11

assembly opening

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 19522329 A1 [0006]
• DE 9316543 U1 [0006]
• DE 112009002657 T5 [0008]

Claims (10)

Fastening arrangement (1) of a printed circuit board-mounted component (2), having - an electrical or electronic component (2) with a base body (4) and with at least one connection (8), - a printed circuit board (3) with a mounting side (3a) for the component (2) and with a board rear side (3b) opposite this and with at least one soldering surface (9) on which the connection (8) of the component (2) makes electrical contact or can be contacted, in particular soldered, - wherein a recess (7) is introduced into the printed circuit board (3), in which the base body (4) of the component (2) is arranged, with its respective connection (8) coming out of the recess (7) for contacting with the soldering surface ( 9) is brought out. Fastening arrangement (1) after claim 1 , characterized in that the recess (7) is closed on the peripheral side or is open on one side, in particular on a longitudinal side. Fastening arrangement (1) after claim 1 or 2 , characterized in that the connection (8) of the component (2) is flattened to form at least one flat side (8a, 8b). Fastening arrangement (1) after claim 3 , characterized in that the terminal (8) of the component (2) rests with the flat side (8b) on the soldering surface (3). Fastening arrangement (1) according to one of Claims 1 until 3 , characterized in that the terminal (8) of the component (2) has a terminal section (10) bent over, preferably at right angles. Fastening arrangement (1) according to one of Claims 1 until 4 , characterized in that the printed circuit board (3) has an assembly opening (11) into which the connection (8) or its connection section (10) is inserted or can be inserted. Fastening arrangement (1) according to one of Claims 1 until 6 , characterized in that the component (2) projects beyond the printed circuit board (3) on the mounting side (3a) and on the back of the board (3b) normal to the printed circuit board level (xy). Fastening arrangement (1) according to one of Claims 1 until 7 , characterized in that the component (2) is a choke coil whose coil winding (5) forms the base body (4) and whose coil ends form the respective terminal (8) of the component (2). Fastening arrangement (1) after claim 8 , characterized in that the component (2) has a coil core (6) which forms the base body (4) with the coil winding (5). Electric motor, in particular a motor vehicle radiator fan motor, with a fastening arrangement (1) according to one of Claims 1 until 9 .

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