Printed circuit board assembly, control electronics and electric motor drive unit

Abstract

The invention relates to a printed circuit board arrangement (12), an electronic control device (14) and an electric motor drive unit (10), comprising a first printed circuit board section (21) and a second printed circuit board section (22), the first printed circuit board section (21) and the second printed circuit board section (22) being arranged substantially parallel to one another at a distance (26), wherein a spacer (28) for mechanically fixing the two printed circuit board sections (21, 22) is arranged between the two printed circuit board sections (21, 22), and the spacer (28) comprises a heat dissipation element (24) made of metal, which is connected to an electronic component (50) of the first or second printed circuit board section (21, 22) in a thermally conductive manner.

Description

Technical Field

[0001] The invention relates to a printed circuit board arrangement having a first and a second printed circuit board section, and to an electronic control unit and an electric motor-type drive unit comprising such a printed circuit board arrangement. Background Art

[0002] DE 102018204297 A1 discloses an electric motor having a motor housing made of metal. A plug component is arranged axially on the motor housing, and a cover made of a material with good thermal conductivity is arranged on the plug component. Two separately constructed, parallel printed circuit boards are arranged in the plug component, each equipped with electronic components. The electronic components of the upper printed circuit board can be in direct thermal contact with the metal cover for cooling. In contrast, the lower printed circuit board is shielded from the metal housing by the upper printed circuit board, making it more susceptible to overheating. Therefore, the object of the present invention is to effectively dissipate heat from all electronic components of the two parallel printed circuit boards. Summary of the Invention

[0003] In contrast, the printed circuit board arrangement according to the present invention, as well as the control electronics and electric motor-type drive unit containing such a printed circuit board arrangement, offers the following advantages: by integrating the heat dissipation element into the spacer between the two printed circuit board sections, all areas of the printed circuit board arrangement can be adequately cooled. This allows for free selection of the arrangement of the electronic components on the two printed circuit boards, thereby enabling optimal use of the parallel printed circuit board arrangement to reduce the installation space of the control electronics. Thus, the spacer between the printed circuit boards can be used both for mechanically positioning and holding the two printed circuit boards and, at the same time, for heat dissipation of the electronic components, which have no direct thermal contact with the cooling housing wall.

[0004] The measures described below provide advantageous improvements and enhancements to the above-described technical solution. It is particularly advantageous that the heat dissipation element of the spacer extends flat over the largest portion of the printed circuit board segment. This allows electronic components that do not face the housing wall to be in thermal contact with a heat sink, which is preferably stamped from sheet metal or copper. The heat sink is a component of the spacer, which is arranged between the two printed circuit board segments to hold them. A plastic holder is molded onto the heat sink, which rests against the printed circuit board segments in an electrically insulating manner. This allows the printed circuit board segments to be held at a fixed distance in a transverse direction perpendicular to the extent of the printed circuit board segments, while also allowing sufficient heat dissipation from the electronic components over the entire surface of at least one of the two printed circuit board segments.

[0005] To dissipate heat from electronic components that generate particularly high amounts of heat, cooling surfaces are formed into the heat sink, which are spaced closer to the electronic components than to the remaining surfaces of the heat sink. These cooling surfaces are preferably pressed into the heat sink by deep drawing or embossing, so that the preferably flat cooling surfaces extend directly toward the components to be dissipated. To increase the thermal contact between the cooling surfaces and the electronic components, a thermally conductive paste can be applied between them, which increases the heat conduction between the electronic components and the heat sink. Forming the cooling surfaces at a closer distance from the electronic components than to the remaining surfaces of the cooling plate has the advantage that sufficient electrical insulation from the printed circuit board sections is ensured in the remaining areas, which have a greater distance.

[0006] In a preferred embodiment, the heat sink is not centrally arranged between two parallel printed circuit board sections, but rather is spaced transversely to the direction of extension at a greater distance from the first printed circuit board section than from the second printed circuit board section. This arrangement allows the first printed circuit board section to dissipate heat, for example, via a metal housing wall, while the second printed circuit board section, which is not directly adjacent to the housing wall, can be cooled by the heat sink. The heat sink extends at a small distance, particularly over the entire second printed circuit board section. The heat sink can dissipate its heat to the air inside the electronics housing or, in alternative embodiments, can also be in thermal contact with the housing wall.

[0007] The heat sink also serves to stabilize the spacer between the two printed circuit board sections by forming tongues on the outer edges of the heat sink that extend transversely to the direction of extension of the printed circuit board sections. These tongues can very advantageously be designed together with the heat sink as bent stampings, with the tongues preferably being bent approximately at right angles at the outer edges of the heat sink. This results in the heat sink's stamped sheet metal forming a kind of basin, with the tongues formed only at the edges of the heat sink where support transverse to the direction of extension is necessary.

[0008] In order to integrate the heat sink into the spacer, a plastic holder can be formed very cost-effectively at the bent plate tongues by means of injection molding. The bent plate tongues form a mechanically stable support for the spacer, wherein the plastic holder has electrically insulating receptacles for the two printed circuit board sections.

[0009] It is particularly advantageous to completely encapsulate the plate tongue with the plastic holder by injection molding, thereby making the plate tongue completely electrically insulated. This makes it easier to fix the two printed circuit board sections at the plastic holder and to assemble the plastic holder and the printed circuit board sections in the electronic device housing, so that no electrical short circuits occur. In this case, the plastic holder can be constructed in a simple manner as a plastic wall, which extends from the heat sink along the plate tongue transversely to the extension direction. In this case, the extension of the plastic holder transversely to the extension direction predetermines the spacing between the two printed circuit board sections. The plastic wall can surround a plurality of individual plate tongues so that it extends at least within the range of a portion of the outer edge of the heat sink and thus forms at least one partially surrounding wall transversely to the heat sink.

[0010] To secure the two printed circuit board segments, positioning elements and support points are formed on the plastic holder at both ends transverse to the direction of extension, via which the two printed circuit board segments rest in a defined position on the spacer. Furthermore, advantageously integrated locking elements are formed so that the two printed circuit board segments lock with the plastic holder when they abut against it, thereby directly and securely securing them on the spacer. Furthermore, additional fixing elements can also be formed on the plastic holder, by means of which the printed circuit board arrangement is positioned and / or secured in the electronics housing. These can be, for example, screw domes or integrated threaded sleeves.

[0011] In a preferred embodiment, a grounding element is formed on the heat sink. This grounding element is electrically insulated from the heat sink and electrically connects the first printed circuit board section to the second printed circuit board section. The formation of such a grounding element between the two printed circuit board sections can improve the electromagnetic compatibility (EMC) of the printed circuit board arrangement, thereby not only improving shielding against external interference radiation but also reducing the generation of internal interference radiation. The grounding element penetrates the heat sink transversely to its direction of extension, with a cutout being punched into the heat sink in advance for this purpose. The grounding element is, for example, formed as a metal tube extending transversely to the heat sink. The metal tube is, for example, sheathed with plastic, which can be formed integrally with the surrounding wall of the plastic holder.

[0012] Particularly advantageously, the two printed circuit board sections can be configured as a so-called 3D semi-flexible printed circuit board (PCB), in which the two parallel printed circuit board sections are integrally connected to one another via a curved printed circuit board region. This allows electronic conductors to be routed from the first printed circuit board section to the second without additional contacting effort. The curved printed circuit board region is, for example, a 180°-angled, U-shaped region or two approximately 90° bends with a spacing region extending transversely to the two printed circuit board sections. The curved printed circuit board region preferably does not extend over the entire longitudinal extent of the two printed circuit board sections, but only at their two end regions. This creates a through-opening between the two curved printed circuit board regions in the center of their longitudinal extent, thereby improving air circulation between the two printed circuit board sections, for example.

[0013] Because the heat sink preferably extends over the entire area of ​​the second printed circuit board section, any electronic components can be arranged on the second printed circuit board section. For example, microprocessors or power semiconductors or capacitors for operating the stator coils require particularly efficient heat dissipation. Therefore, cooling surfaces are appropriately shaped opposite the electronic components and are preferably connected to the microprocessor and / or the power semiconductors and / or the capacitors and / or other electronic components using thermally conductive paste.

[0014] In contrast, the electronic components of the first PCB section can be thermally connected to the housing wall of the control electronics, which is particularly made of metal and has external heat-conducting elements. The corresponding electronic components can also be connected to the inner wall of the metal housing using thermal paste. This allows the first PCB section to be cooled by the cooled housing wall, and the second PCB section to be cooled by the heat sink. The latter (the second PCB section) either dissipates its heat solely through air convection, or the heat sink is also additionally connected to the housing wall of the control electronics or the electric motor. The control PCB arrangement can be very easily positioned and, if necessary, secured in the housing of the control electronics using a plastic holder formed on the spacer.

[0015] Such control electronics with the printed circuit board arrangement are preferably components of a drive unit in which an electric motor can drive an electric motor via an output element or can adjust movable components, in particular in a motor vehicle. In such electric motor-type drive units, it is particularly advantageous to design a portion of the electronics housing as a metal cover, which serves to dissipate heat from the printed circuit board arrangement.

[0016] The metal second housing part of the electronics housing is designed as a cover for the motor housing. A plastic first housing part is formed interposed between the metal cover of the electronics housing and the motor housing, which is preferably also made of metal. A connection plate for controlling the stator coils of the electric motor is arranged in the plastic first housing part. The corresponding connected stator coils are connected to a printed circuit board arrangement via phase connectors, where they are controlled by corresponding control electronics for electronic commutation of the rotor. The rotor shaft particularly advantageously extends axially into the electronics housing with its free end, so that a signal transmitter arranged on the rotor shaft can interact directly with a corresponding sensor device on the second printed circuit board section. The two printed circuit board sections are arranged within the electronics housing, spaced apart from each other and transversely to the axis of the rotor shaft.

[0017] By arranging the control electronics directly axially above the electric motor, a signal transmitter can advantageously be arranged at the end of the rotor shaft, interacting with a corresponding sensor of the control electronics. In this way, the rotor position can be detected by the control electronics, for example, to control the electronic commutation of the electric motor or to determine the rotational speed of the rotor shaft or the position of a component driven by the rotor shaft. A bearing shield is preferably arranged on the open side of the motor housing, in which the rotor shaft is supported, for example, by means of rolling bearings. The rotor shaft passes through the bearing shield and projects into the electronics housing. The arrangement of the electronics housing on the axially open side of the motor housing allows for a through-opening to be formed in the bottom of the pole pot on the opposite side of the motor housing, through which the rotor shaft projects outward. Consequently, a driven element can be formed or arranged at the second free axial end of the rotor shaft, which drives, for example, a movable component in the motor vehicle or a pump or blower. In this example, the driven element is designed for operation at high temperatures of approximately 140° C. or 160° C. or up to approximately 140° C. or 160° C., in particular for semi-flexible printed circuit boards. Furthermore, in this example, the electromechanical system of the drive unit is designed for operation at high vibrations of approximately 25 or 35 times the acceleration of gravity or up to approximately 25 or 35 times the acceleration of gravity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features of the present invention, as described in the following embodiments of the present invention, can be derived from the other embodiments of the description and the accompanying drawings. Among them:

[0019] Figure 1 An embodiment of a printed circuit board arrangement according to the invention is shown;

[0020] Figure 2 shows a detailed view of the heat dissipating element before its assembly;

[0021] Figure 3 Shown with injection molded retaining elements Figure 2 heat dissipation components; and

[0022] Figure 4 An exemplary embodiment of an electric drive unit according to the invention with a printed circuit board arrangement is shown. DETAILED DESCRIPTION

[0023] exist Figure 11 shows a printed circuit board arrangement 12 for control electronics 14 of an electric motor-type drive unit 10. In this printed circuit board arrangement 12, a first printed circuit board section 21 is arranged at a distance 26 from a second printed circuit board section 22. The two printed circuit board sections 21, 22 are arranged approximately aligned with one another, with the distance 26 being, for example, 1 to 3 centimeters transverse to the direction of extension 20 of the printed circuit board sections 21, 22. As a result, the printed circuit board sections 21, 22 are aligned approximately parallel to one another. A spacer 28 is arranged between the two printed circuit board sections 21, 22, to which the printed circuit board sections 21, 22 are secured. For this purpose, positioning elements 36 and locking elements 38 are formed on the spacer 28, which secure the two printed circuit board sections 21, 22. In this embodiment, the printed circuit board arrangement 12 is designed as a semi-flexible printed circuit board 13, wherein the printed circuit board sections 21, 22 are connected to one another by means of a printed circuit board region 16. The bent PCB region 16 consists of two approximately 90° bends 17, resulting in the two PCB sections 21, 22 forming an angle of approximately 180° relative to each other. The two bent PCB regions 16 are each formed only at opposite end regions 54 of the PCB sections 21, 22, resulting in a through-opening 15 formed centrally between the two end regions 54 and the two PCB sections 21, 22. The spacer 28 includes a heat dissipation element 24, which extends approximately parallel to the PCB sections 21, 22. The heat dissipation element 24 is preferably designed as a heat sink 25, which extends adjacent to the electronic component 50, which faces the heat sink 25 from, in particular, the second PCB section 22. To bring the heat sink 25 closer to the electronic component 50, a cooling surface 23 is formed in the heat sink 25 in the form of a projection, which is spaced closer to the electronic component 50 than to the rest of the heat sink 25. In particular, heat sink 25 is in thermal contact with electronic components 50, preferably microprocessor 51 and / or power semiconductor 52 and / or transistor 50 or capacitor 53, at cooling surface 23 by means of thermally conductive paste 19. Heat sink 25 preferably has no insulation in the region along the plane of second printed circuit board section 22, so that heat from heat sink 25 can be dissipated directly to the air between the two printed circuit board sections 21, 22. Spacer 28 includes a plastic holder 30 that extends approximately at a right angle from planar heat sink 25 toward first printed circuit board section 21. Plastic holder 30 is arranged at end regions 54 of printed circuit board sections 21, 22 and forms a circumferential wall 32 that extends over a portion of both printed circuit board sections 21, 22.The plastic holder 30 predetermines the distance 26 between the two printed circuit board sections 21, 22 and secures the two printed circuit board sections 21, 22 to the spacer 28. For this purpose, positioning elements 36 are formed at the ends of the plastic holder 30, which precisely determine the position of the two printed circuit board sections 21, 22. Additionally, locking hooks 38 are formed as securing elements, for example, which securely hold the two printed circuit board sections 21, 22 in the defined position. The locking hooks 38 press the two printed circuit board sections 21, 22 against support points 37 defined by the plastic holder 30. Figure 1 In the embodiment, on the first printed circuit board section 21 , an electronic component 50 is arranged on the outer side facing away from the spacer 28 , which electronic component 50 , for example when installed in the control electronics 14 , can be in direct thermal contact with the housing parts 81 , 82 serving as heat sinks.

[0024] exist Figure 2 It is shown that, for example, Figure 1 The heat sink 25 used in the embodiment of the present invention is provided. The heat sink 25 extends approximately parallel to and in line with the printed circuit board section 22 along the extension direction 20, and the electronic components 50 of the printed circuit board section 22 are to be cooled. Figure 2 In the heat sink 25, for example, three flat cooling surfaces 23 are pressed into the heat sink 25 in the form of recesses. The first large cooling surface 23 is preferably constructed in the form of a rectangle or square in the center of the heat sink 25 so as to fully thermally contact the microprocessor 51. At the edge area of ​​the heat sink 25, a plate tongue 34 is integrally formed, which is bent at an approximately right angle from the flat area of ​​the heat sink 25. The plate tongue 34 is formed in the area of ​​the bent printed circuit board area 16 and at the two open opposite end areas 54 of the printed circuit board sections 21, 22. The heat sink 25 can be manufactured in particular as a bent stamped part made of steel or copper. In addition, a perforation 56 is punched out in the flat area of ​​the heat sink element 24, through which a grounding part 40 can be guided, which connects the two printed circuit board sections 21, 22 to each other electrostatically.

[0025] exist Figure 3 In the embodiment, the plastic retainer 30 is formed, preferably injection molded, into Figure 2 The plastic holder 30 completely surrounds the bent plate tongue 34 so that it is electrically insulated from the two printed circuit board sections 21, 22. The plastic holder 30 is preferably designed as a surrounding wall 32, which extends, for example, along the entire end region 54 of the two printed circuit board sections 21, 22. Figure 3In the embodiment of the present invention, the surrounding wall 32 extends around the corner of the heat sink 25 as far as the through-opening 15 between the two bent-over printed circuit board regions 16. Abutment surfaces 37, positioning elements 36, and locking elements 38 are integrally formed on the end faces 33 of the surrounding wall 32 for properly securing the printed circuit board sections 21, 22 to the plastic holder 30. Furthermore, a grounding element 40 is inserted into the opening 56, which is designed here as a metal sleeve 41 surrounded by a plastic shell 42 serving as electrical insulation. The grounding element 40 extends transversely to the heat sink 25 and has approximately the same extent in the transverse direction 18 as the surrounding wall 32.

[0026] Figure 4 An axial cross-section through an electric drive unit 10 with a printed circuit board arrangement 12 according to the present invention is shown. The rotating electric drive unit 10 is designed, for example, as an electronically commutated internal rotor motor and includes a stator 60 with inwardly directed stator teeth 61, which are surrounded on the outside by a cylindrical motor housing 62. A rotor 64, provided with permanent magnets 65, is rotatably arranged in the interior surrounded by the stator teeth 61. Stator coils 63 are wound around the stator teeth 61. During operation of the drive unit 10, a suitable voltage is applied to these stator coils 63 by means of the printed circuit board arrangement 12 provided in the control electronics 14 for electronic commutation, thereby generating a moving magnetic field in the interior of the electric motor 8. This generates the torque required to rotate the rotor 64. In this exemplary embodiment, the rotor 64 is supported at the bottom of the motor housing 62 by means of a first bearing 68. To this end, the motor housing 62 has an axial projection 70 that serves as a bearing seat for the first bearing 68. The motor housing 62 is manufactured from metal, for example, as a deep-drawn part. The rotor shaft 66 of the rotor 64 projects through an opening in the motor housing 62 to transmit the torque of the electric motor 8 to a transmission mechanism or a pump or blower (not shown in detail). The driven element 74 is arranged on or integrally formed on the rotor shaft 66.

[0027] The cylindrical motor housing 62 has an open flange 76 on the side opposite the bearing 68. In this exemplary embodiment, an electronics housing 80 rests axially against this open flange 76. The electronics housing 80 consists of an axial first housing portion 81 and an axial second housing portion 82. Together, the motor housing 62 and the electronics housing 80 form the housing 11 of the drive unit 10. The bearing cover 67 with the second bearing 69 and the coupling plate 78 are integrated into the electronics housing 80. A first free end 65 of the rotor shaft 66, opposite the driven element 74, protrudes through the second bearing 69. A signal transmitter 83 for detecting the rotor position is arranged at this first free end. A sensor element 94 is arranged axially opposite the signal transmitter 83 on the second printed circuit board section 22. The signal transmitter 83 is designed, for example, as a sensor magnet 84, whose axial magnetic field can be detected by the sensor element 94, which is designed as a magnetic sensor 95. This can be designed, for example, as a GMR sensor or GMX sensor 95, which can directly detect the rotational position of the sensor magnet 84. The control electronics 14 can analyze this signal in order to thereby control, for example, the electronic commutation of the electronically commutated motor 8. Furthermore, the rotational position signal can also be used to detect the movement of the driven element 74 for various applications.

[0028] The connecting plate 78 connects the individual stator coils 63 to one another and forms an electrical phase connection 79 that allows the current supply to the stator coils 63 to be passed axially through the wall of the electronics housing 80 from the interior of the motor housing 62 into the electronics housing 80. The phase connection 79 is connected to the second printed circuit board section 22 to control the stator coils 63 accordingly. In this embodiment, a connecting plug 88 for electrically contacting the drive unit 10 is arranged on the first housing part 81. The connecting plug 88 has a plug flange 89 extending in the radial direction 7, in which separate connection pins for the power supply and the sensor signals are arranged. The second housing part 82 is made of aluminum for better heat dissipation. The aluminum housing 82 is manufactured, for example, by injection molding or die casting. Heat-conducting elements 86, for example, in the form of cooling ribs 87 or cooling junctions, are integrally formed on the outer wall of the second housing part 82. The electronic component 50 arranged on the upper side of the first printed circuit board section 21 can here also preferably be brought into thermal contact with the second housing section 82 by means of a heat-conducting paste 19 .

[0029] Arranged on the printed circuit board sections 21 and 22 as further electronic components 50 are, for example, a microprocessor 51, power semiconductor elements 52, and interference suppression components. The arrangement of these electronic components 50 on the two printed circuit board sections 21 and 22 can be freely varied depending on the requirements (installation space, heat dissipation, signal transmitters) because the latter can be wired accordingly like a single, large printed circuit board, either by means of a curved printed circuit board area 16 or by means of electrical contacting of the two separately constructed printed circuit board sections 21 and 22. The heat dissipation of the second printed circuit board section 22 is achieved here by means of a heat sink 25, which dissipates the heat to the air within the electronics housing 80. In an alternative embodiment, the heat sink 25 can also be directly connected to the heat-conducting element 86 of the electronics housing 80. The heat sink 25, which extends flat in the radial direction 7 over the entire second printed circuit board section 22, also serves to improve electromagnetic compatibility (EMC). ) for both injection and ejection. Another auxiliary function of the spacer 28 is mechanically reinforcing the two printed circuit board sections 21, 22, particularly when the two printed circuit board sections 21, 22 are designed as 3D semi-flexible printed circuit boards. Due to this temperature and vibration stability, the electromechanical system of the drive unit 10 can also be used in motor vehicles, such as in motor cooling systems, in other circular rotors, or in servo drives in motor compartments.

[0030] It should be noted that various combinations of the individual features of the exemplary embodiments shown in the drawings and description are possible. Thus, the two printed circuit board sections 21, 22 can be constructed as separate printed circuit boards or as a single semi-flexible printed circuit board. In principle, the heat dissipation element 24 can also have a different design from a flat, plate-shaped one, or the tabs 34 formed on the heat dissipation element 24 can have a bend other than 90°. The shape of the plastic holder can also be adapted to the geometry of the printed circuit board sections 21, 22. The spacer 28 can be designed solely to accommodate the printed circuit board sections 21, 22 or to also position and / or secure the printed circuit board arrangement 12 within the housing 11. The drive unit 10 according to the present invention is particularly suitable as an embodiment of an electronically commutated motor 8 for adjusting movable components or for use in rotary drives in motor vehicles. Such electric motors 8 according to the present invention are particularly advantageous for use in exterior areas, such as in motor compartments, where they are subject to extreme weather conditions and vibrations.

Claims

1. A printed circuit board arrangement (12) comprising a first printed circuit board section (21) and a second printed circuit board section (22), the first printed circuit board section (21) and the second printed circuit board section (22) being arranged substantially parallel to one another at a distance (26), wherein a spacer (28) is arranged between the two printed circuit board sections (21, 22) for mechanically fixing the two printed circuit board sections (21, 22), and the spacer (28) comprises a heat dissipation element (24) made of metal, the heat dissipation element (24) being connected to an electronic component (50) of the first or second printed circuit board section (21, 22) in a thermally conductive manner, wherein: The heat dissipation element (24) is designed as a heat dissipation plate (25), which extends substantially parallel to the second printed circuit board section (22), and a plastic holder (30) is formed on the heat dissipation plate (25), which rests on the printed circuit board section in an electrically insulating manner and fixes the two printed circuit board sections (21, 22) on the plastic holder (30).

2. The printed circuit board arrangement (12) according to claim 1, characterized in that A cooling surface (23) is formed in the heat sink (25) in the region of the electronic component (50) in the form of a recess in the heat sink (25), the cooling surface (23) extending opposite the electronic component (50).

3. The printed circuit board arrangement (12) according to claim 1 or 2, characterized in that The distance between the heat dissipation plate (25) and the second printed circuit board section (22) is smaller than the distance between the heat dissipation plate (25) and the first printed circuit board section (21), so that the first printed circuit board section (21) dissipates heat through the housing wall, while the second printed circuit board section not directly arranged along the housing wall can be cooled by the heat dissipation plate (25), and a plate tongue (34) is integrally formed in a rectangular shape on the heat dissipation plate (25), and the plate tongue (34) extends toward the first printed circuit board section (21).

4. The printed circuit board arrangement (12) according to claim 3, characterized in that The plastic holder (30) is fixed to the plate tongue (34) by means of plastic injection molding.

5. The printed circuit board arrangement (12) according to claim 3, characterized in that The plastic holder (30) completely surrounds the board tongue (34), so that the board tongue (34) is completely electrically insulated from the two printed circuit board sections (21, 22).

6. The printed circuit board arrangement (12) according to claim 1 or 2, characterized in that Positioning elements (36) and / or screwing points and / or bearing points (37) and / or locking elements (38) for the two printed circuit board sections (21, 22) are integrally formed on the plastic holder (30).

7. The printed circuit board arrangement (12) according to claim 1 or 2, characterized in that A grounding element (40) is arranged on the heat sink (25), which penetrates the heat sink (25) and connects the two printed circuit board sections (21, 22) to each other in an electrically conductive manner.

8. The printed circuit board arrangement (12) according to claim 1 or 2, characterized in that The two printed circuit board sections (21, 22) are connected to one another by means of a bent printed circuit board region (16) to form a semi-flexible printed circuit board (13).

9. The printed circuit board arrangement (12) according to claim 1 or 2, characterized in that The electronic component (50) on the second printed circuit board section (22) is configured as a microprocessor (51) and / or a power semiconductor (52) and / or a capacitor (53), and the electronic component (50) on the second printed circuit board section (22) dissipates heat through the heat dissipation element (24).

10. The printed circuit board arrangement (12) according to claim 1, characterized in that The printed circuit board arrangement (12) is used for control electronics (14) of an electric motor-type drive unit (10).

11. The printed circuit board arrangement (12) according to claim 2, characterized in that The cooling surface (23) is connected to the electronic component (50) by means of a thermally conductive paste (19).

12. The printed circuit board arrangement (12) according to claim 4, characterized in that The plastic holder (30) forms a surrounding wall (32) transverse to the heat sink (25).

13. The printed circuit board arrangement (12) according to claim 7, characterized in that The grounding element (40) is configured as a metal sleeve (41).

14. The printed circuit board arrangement (12) according to claim 13, characterized in that The metal sleeve (41) is covered with plastic (42).

15. The printed circuit board arrangement (12) according to claim 8, characterized in that The bent printed circuit board region (16) has two 90° bends (17).

16. Control electronics (14) of an electric motor-type drive unit (10) with a printed circuit board arrangement (12) according to any one of claims 1 to 15, characterized in that The electronic components (50) of the first printed circuit board section (21) are directly thermally connected to the metallic second housing part (82) of the control electronics (14), and the electronic components (50) of the second printed circuit board section (22) have no direct thermal contact with the metallic second housing part (82).

17. Control electronics (14) according to claim 16, characterized in that The electronic components (50) of the second printed circuit board section (22) release heat to the air in the interior of the control electronics (14) via the heat dissipation element (24).

18. Control electronics (14) of an electric motor-type drive unit (10) with a printed circuit board arrangement (12) according to any one of claims 1 to 15, characterized in that The second printed circuit board section (22) is directly connected in a heat-conducting manner to a metallic second housing part (82) of the electronics housing (80) or to the motor housing (62).

19. Control electronics (14) according to any one of claims 16 to 18, characterized in that The printed circuit board arrangement (12) is positioned in the control electronics (14) by means of a plastic holder (30).

20. An electric motor drive unit (10) with an axially open motor housing (62), in which a stator (60) and a rotor (64) are arranged, and with control electronics (14) according to any one of claims 16 to 19, characterized in that The metallic second housing part (82) is designed as a cover for the motor housing (62).

21. The electric motor drive unit (10) according to claim 20, characterized in that A first, central housing part (81) made of plastic is arranged between the motor housing (62) and a second, metallic housing part (82) serving as a cover, a connection device (78) for an electric coil (63) of the stator (60) is arranged in the first, central housing part (81), and the two printed circuit board sections (21, 22) are aligned transversely to the rotor shaft (66) and are connected to the connection device (78) for actuating the electric coil (63).

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