Circuit arrangement and control unit

Abstract

The invention relates to a circuit arrangement (10) comprising a printed circuit board (12) on which at least one heat-generating component (1) is arranged, comprising a voltage supply for the at least one component (1), which voltage supply comprises a busbar arrangement (20) arranged on a surface of the printed circuit board (12), with a first contact on the busbar arrangement (20) designed as a press-in connection for contacting a voltage source and a second contact on the busbar arrangement (20) for electrically connecting the at least one component.

Description

Technical area

[0001] The invention relates to a circuit arrangement characterized by a particularly advantageous thermomechanical design of a printed circuit board in conjunction with a busbar arrangement connected to the printed circuit board. Furthermore, the invention relates to a control device with a circuit arrangement designed according to the invention. State of the art

[0002] From EP 2 043 412 A1, a circuit arrangement having the features of the preamble of claim 1 is known. The known circuit arrangement comprises a busbar arrangement with a busbar which is thermally and electrically connected on one side to a heat-generating component and which is connected on the side opposite the component to a heat sink with cooling fins.

[0003] Furthermore, DE 10 2016 206 234 A1 discloses a circuit arrangement in which a power semiconductor component in the form of a MOSFET component is arranged on a printed circuit board, wherein the printed circuit board is coupled via a press-in contact to busbars which are also arranged on the printed circuit board next to the printed circuit board and serve to supply power to an electric motor. Disclosure of the invention

[0004] The circuit arrangement according to the invention with the features of claim 1 has the advantage that it exhibits an at least virtually constant geometry and no or only minimal deformation or bending, even under high current loads and / or high thermal cycling stresses. As a result, the electrical contacts on the busbar arrangement, which typically comprise soldered connections, are subjected to minimal mechanical stress, thus ensuring particularly high reliability over the entire service life of the circuit arrangement.

[0005] The invention is based on the idea of ​​not only arranging a busbar for supplying current and dissipating heat on a single side of a printed circuit board - as is known in the prior art - but also an additional second busbar on the side of the circuit board opposite the one busbar, which is thermally coupled to the first busbar, preferably by means of an electrical contact or connection. This makes it possible for both busbars to expand or contract at least approximately equally under thermal stress due to their different coefficients of thermal expansion compared to the circuit board material, so that the geometry of the circuit arrangement is at least almost always the same, regardless of the current or thermal load. This has the consequence that the thermo-mechanical loads ormechanical stresses in the area of ​​the contacts of the busbars are very low, so that the contacts (soldered connections) have a particularly high quality over the entire operating life or service life of the circuit arrangement.

[0006] Against the background of the above explanations, a circuit arrangement according to the invention with the features of claim 1 therefore has a printed circuit board on which at least one heat-generating component is arranged. Furthermore, a voltage supply for the at least one component is provided, which voltage supply comprises a busbar arrangement arranged on a surface of the printed circuit board. By means of a first contact, designed as a press-in connection, contacting of the busbar arrangement with a voltage source is enabled on the busbar arrangement, and by means of a second contact, contacting of the at least one component is enabled. According to the invention, it is provided that the circuit arrangement has a busbar arrangement which, on the surface of the printed circuit board opposite the first busbar, has a second busbar which is connected to the first busbar, preferably in an electrically conductive manner.

[0007] Advantageous further developments of the circuit arrangement according to the invention are listed in the subclaims.

[0008] To achieve the most identical expansion behavior of the two busbars possible, the second busbar is provided with at least approximately the same geometry as the first busbar. At least approximately identical geometry refers to both an at least approximately identical shape and at least approximately identical dimensions (including thickness) of the second busbar. In particular, the two busbars are arranged in at least partial, preferably complete, overlap with each other.

[0009] Optimizing the expansion behavior of the assembly consisting of the circuit board and the two busbars is achieved when the circuit board has a plane of symmetry running parallel to the two busbars. In other words, this means that the circuit board has an identical number of layers or electrically conductive layers on both sides of the plane of symmetry.

[0010] While the first contact provided on the busbars for the voltage supply is designed in the form of a press-in connection, the second contact has the option of being designed either as a press-in connection, depending on the design(s) of the components, or, in the event that the at least one component is designed as an SMD component, of designing the second contact as a soldered connection.

[0011] To relieve thermal stress or dissipate heat from the at least one component, it is further provided that the at least one component covers the first busbar at least in part and is thermally connected to the first busbar. The thermal connection can in particular be in the form of a soldered connection. Depending on the application or design of the component, however, it is also conceivable to form the thermal connection using a thermally conductive adhesive. This is particularly advantageous when the component is connected to the circuit board via press-in connections, so that a gap typically formed between the busbar and the underside of the component can be easily bridged by the thermally conductive adhesive.

[0012] The circuit arrangement according to the invention is also preferably used in components which are designed as MOSFET components.

[0013] In a further development of the last proposal, the busbar arrangement is arranged in operative connection with several MOSFET components arranged directly next to one another.

[0014] Finally, the invention also includes a control device, in particular for motor vehicle applications, with a circuit arrangement designed according to the invention as described so far.

[0015] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawings. Short description of the drawings Fig. 1 shows a section of a circuit arrangement of a control unit in a perspective view, Fig. 2 a section in the area of ​​a busbar arrangement of the circuit arrangement according to Fig. 1 and Fig. 3 a longitudinal section in the area of ​​a busbar arrangement. Embodiments of the invention

[0016] Identical elements or elements with the same function are provided with the same reference numbers in the figures.

[0017] The figures show a circuit arrangement 10 which is a component of an electronic circuit of a control unit 100, in particular for motor vehicle applications.

[0018] The circuit arrangement 10 comprises a multi-layer printed circuit board 12, on which a plurality of electronic or electrical components 1, 2 are arranged, forming an electronic circuit. The components 1 are components 1 which generate heat during their operation, which must be dissipated to the environment by suitable measures. In contrast, the components 2 are components 2 which typically generate a non-critical amount of heat during their operation. In particular, the components 1 within the scope of the invention can be MOSFET components 3. The MOSFET components 3 are Fig. 1 and Fig. 2 is designed in the form of surface-mounted SMD components 5. According to the illustration of the Fig. 3, however, it can also be provided that the components 1 are electrically connected to the circuit board 12 via press-in contacts 14.

[0019] The voltage supply to the components 1 relevant to the invention is effected via press-in pins 16 connected to a voltage source (not shown) as contacts, which are part of a connector strip 18. In addition to the press-in pins 16 for supplying voltage to the components 1, a plurality of further press-in pins 19 are provided on the connector strip 18, which serve, for example, to supply sensor signals or to control components by the control unit 100 as a result of the electronic circuit.

[0020] In the Fig. 1 and Fig. 2 shows that the circuit arrangement 10 comprises four identically designed MOSFET components 3 arranged directly next to one another in the form of SMD components 5, which are arranged in a 2x2 matrix. The MOSFET components 3 are arranged in the immediate vicinity of the press-in pins 16 serving as the power supply.

[0021] The circuit board 12 further comprises at least one busbar arrangement 20 comprising two busbars 22, 24. The two busbars 22, 24 are made of a material with good thermal conductivity, in particular copper, and are arranged on opposite surfaces of the circuit board 12, i.e., in the region of the top side and in the region of the bottom side of the circuit board 12, and are connected to the circuit board 12. Preferably, the two busbars 22, 24 have at least approximately the same geometry and are arranged on the opposite sides of the circuit board 12, overlapping one another at least in some areas, preferably completely.

[0022] The busbars 22, 24 serve, on the one hand, to supply voltage to the components 1 and, on the other hand, to dissipate the heat generated during operation of the components 1 by thermal contact between the components 1 and the busbars 22, 24, in particular by means of the busbar 22.

[0023] In the illustrated embodiment, the two busbars 22, 24 are approximately T-shaped and have the same geometry, size, and thickness. A first section 26 of the busbar 22 has, for example, six through-openings 28 for forming the press-in connections with the press-in pins 16. A second section 30 is approximately rectangular and arranged in overlap with the four MOSFET components 3. The upper busbar 22 is thermally connected to the MOSFET components 3 by a soldered connection. The electrical contacting of the MOSFET components 3 is also carried out via the soldered connection. Alternatively, it can also be provided that, in accordance with the Fig. 3 a thermally conductive agent 32 in the form of a thermally conductive adhesive 33 is arranged between the component 1 and the busbar 22.

[0024] In the Fig. 3 also shows that both busbars 22 and 24 can be electrically connected to each other via the press-in contacts 14 and the press-in pins 16.

[0025] Also in the Fig. 3 shows that the printed circuit board 12 has a plane of symmetry 38 arranged parallel to the plane of the printed circuit board or to the two busbars 22, 24, wherein the same number of electrically conductive layers or the same number of layers is present on both sides of the plane of symmetry 38, as is one of the two busbars 22 and 24.

[0026] The circuit arrangement 10 or the control unit 100 described so far can be modified in many different ways without deviating from the inventive concept. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 043 412 A1

[0002] DE 10 2016 206 234 A1

[0003]

Claims

[1] Circuit arrangement (10), with a printed circuit board (12) on which at least one heat-generating component (1) is arranged, with a voltage supply for the at least one component (1), which comprises a busbar arrangement (20) arranged on a surface of the printed circuit board (12), with a first contact on the busbar arrangement (20) designed as a press-in connection for contacting a voltage source and a second contact on the busbar arrangement (20) for electrically connecting the at least one component (1), characterized by that the busbar arrangement (20) has a second busbar (24) on the surface of the printed circuit board (12) opposite a first busbar (22), which is connected to the first busbar (22), preferably in an electrically conductive manner. [2] Circuit arrangement according to claim 1, characterized bythat the second busbar (24) has at least approximately the same geometry as the first busbar (22) and / or that the two busbars (22, 24) are arranged in at least partial, preferably complete overlap on the opposite sides of the printed circuit board (12). [3] Circuit arrangement according to claim 1 or 2, characterized by that the printed circuit board (12) has a plane of symmetry (38) running parallel to the two busbars (22, 24). [4] Circuit arrangement according to one of claims 1 to 3, characterized by that the second contact is designed as a press-in connection. [5] Circuit arrangement according to one of claims 1 to 3, characterized by that the at least one component (1) is designed as an SMD component (5), and that the second contact is designed as a solder connection. [6] Circuit arrangement according to one of claims 1 to 5, characterized bythat the at least one component (1) covers the first busbar (22) at least in regions and is thermally connected to the first busbar (22). [7] Circuit arrangement according to claim 6, characterized by that the thermal connection is designed as a soldered connection. [8] Circuit arrangement according to one of claims 1 to 7, characterized by that the at least one component (1) is designed as a MOSFET component (3). [9] Circuit arrangement according to claim 8, characterized by that the busbar arrangement (20) contacts a plurality of MOSFET components (3) arranged directly next to one another on the printed circuit board (12). [10] Control unit (100), in particular for motor vehicle applications, with a circuit arrangement (10) designed according to one of claims 1 to 9.

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