ELECTRONIC ASSEMBLY WITH AT LEAST ONE PRINTED CIRCUIT BOARD AND EXTERNAL ELECTRONIC COMPONENTS, AND INVERTER WITH SUCH AN ELECTRONIC ASSEMBLY

Description

[0001] The invention relates to an electronic assembly comprising at least one printed circuit board and external electronic components with electrical connections, wherein the printed circuit board has contacts for connection to the connections of the external electronic components, and the at least one printed circuit board and the external components can be fastened to a housing part.

[0002] Furthermore, the invention relates to an inverter, in particular a photovoltaic inverter, with a power section.

[0003] The invention fundamentally relates to general electronic assemblies comprising at least one printed circuit board and external electronic components that are connected to the printed circuit board. The printed circuit board and the external components are typically arranged in a housing or attached to a housing part. The external electronic components are usually higher-performance and larger-volume components, which is why they are not directly attached or soldered to the printed circuit board. For example, larger chokes or capacitors, which generate more heat, are often deliberately placed away from the printed circuit board, for example, in or on their own heat sink.The electrical connection between the external electronic component and corresponding contacts on the circuit board is usually made via cables, at the ends of which screw contacts are arranged, which are screwed to the contacts on the circuit board.

[0004] For example, the electronic module is an inverter or a part of the inverter, such as the power section. In such inverters, especially photovoltaic inverters, individual modules, such as the AC-side power section or the DC-side power section, are arranged in a housing with corresponding external electronic components, such as chokes. For maintenance purposes, it is advantageous to enable the electronic modules to be replaced as quickly and easily as possible.

[0005] Connecting external chokes to the circuit board via screw connections is correspondingly complex. General maintenance or replacement of inverter components, such as repairing the power circuit board, is correspondingly time-consuming and costly. This is further complicated by the fact that components, especially semiconductor components, which are soldered directly to the circuit board are often connected to corresponding heat sinks for cooling. Thermal paste is often placed between the semiconductor components and the heat sinks for improved heat conduction, making disassembly of the circuit board even more complex.

[0006] In addition, when screwing the contacts of external components to the circuit board, the screws may become jammed, making it very difficult to loosen the screw connection.

[0007] In some cases, plug-in connections between circuit boards and external electronic components offer advantages. However, due to tolerances and displacement of the external electronic components relative to the circuit board, problems can arise when establishing the connection between the circuit board and the contacts of the external electronic components.

[0008] For example, DE 10 2008 004 882 A1 describes a plug connection in which the positioning of the plug connection to the circuit board and thus the electrical connection between the contact pin and a corresponding counterpart on the circuit board is supported.

[0009] WO 2012 / 046152 A1 discloses an electronic assembly according to the preamble of claim 1.

[0010] The object of the present invention is to create an electronic assembly and an inverter of the aforementioned type that support the quick and easy replacement of individual components. Disadvantages of the prior art are to be avoided or at least reduced.

[0011] The object of the invention is achieved by an above-mentioned electronic assembly in which a carrier is provided which is displaceably mounted on the housing part, wherein the carrier has holders for receiving contact elements for connecting to the terminals of the external electronic components and for connecting to the contacts on the printed circuit board. The core of the invention is therefore the displaceably mounted carrier with holders for receiving contact elements. The contact elements arranged on the carrier are connected, on the one hand, to the terminals of the external electronic components, which can be achieved by appropriate cable and solder connections but also screw connections. On the other hand, the contact elements arranged on the carrier establish the connection to corresponding contacts on the printed circuit board.The movable mounting of the carrier makes it easier to compensate for tolerances and facilitates the connection of the contact elements to the circuit board. The movable mounting of the carrier when connected to the circuit board also makes it easier to remove any components from heat sinks. Appropriate design of the carrier and the contact elements for connecting to the terminals of the external electronic components and for connecting to the contacts on the circuit board can facilitate the replacement of individual components of the electronic assembly, such as the circuit board or external electronic components, and support rapid repair or replacement of components. The additional manufacturing effort required for the design of the carrier, which is mounted on the housing part so that it can be moved, is very minimal.

[0012] Preferably, the carrier is mounted so that it can be moved in one direction. This ability to move in one direction is usually sufficient to compensate for tolerances between the housing part and the circuit board to be connected, and it is easy to manufacture.

[0013] For example, the displaceable mounting of the carrier in one direction relative to the housing part to which the carrier is connected can be achieved very easily by the carrier having at least one elongated hole for receiving a fastening element, in particular a fastening screw, which fastening element can be connected to the housing part. Displaceability in one direction can be achieved by such an elongated hole and a suitable guide, or by two or more elongated holes with the same orientation of the longitudinal axes of the elongated holes.

[0014] If a locking lug or similar feature is located in at least one slotted hole, a specific preferred position for the fastening element can be defined. This preferred position can be overcome and exited by overcoming the obstacle of the locking lug or similar feature, should this be necessary due to tolerances between the circuit board or housing component and the carrier.

[0015] The carrier is preferably made of plastic, for example, polyamide. This allows for particularly simple and cost-effective production, and the contact elements arranged in the holders can be electrically insulated from one another. For example, the carriers, including the holders and the elongated holes or similar for receiving the fastening elements for attachment to the housing part, can be produced very easily and cost-effectively using injection molding.

[0016] If the carrier is designed as a grid, the weight of the carrier can be reduced to a large extent and access to components, such as the external electronic components arranged under the carrier, can be made easier.

[0017] According to a further feature of the invention, at least one centering pin is arranged on the carrier, which can be arranged in a corresponding centering opening on the circuit board. Such centering pins can assist in the correct positioning of the circuit board with respect to the contact elements arranged on the carrier. Such a centering pin on the carrier can be very easily implemented, particularly when manufacturing the carrier from a plastic using an injection molding process. The corresponding counterpart on the circuit board in the form of a centering opening, possibly a conical bore, can also be manufactured very easily and cost-effectively.

[0018] Preferably, the contact element is formed by a plug that can be connected to a complementary socket on the circuit board. This design allows the connection between the contact elements on the carrier and the circuit board to be established and released particularly quickly and easily, without the need for tools. Depending on the strength of the current that will flow through the respective contact, the contacts and sockets must be selected with an appropriate cross-section to avoid local overheating and problems, or even the destruction of the contact elements.

[0019] As an alternative to the plug-in connection mentioned above, the contact element can also be designed as a screw connection, for example, by having an internal thread for accommodating a screw with a corresponding external thread. This somewhat increases the assembly and disassembly effort, as the screw connection must be closed or loosened manually or automatically. However, for higher transmitted currents and higher power classes, it may be necessary or even mandatory to use screw contacts instead of plug-in contacts.

[0020] Preferably, a heat sink is arranged on the housing part of the electronic assembly, which heat sink can be contacted with components arranged on the underside of the circuit board. In this way, components with higher heat dissipation can be arranged primarily on the underside of the circuit board by appropriately designing the circuit board, where they are automatically contacted by a suitable heat sink during assembly. The size and material of the heat sink are adapted accordingly to the amount of heat to be dissipated.

[0021] A thermal paste can be applied between the components and the heat sink, improving heat conduction from the components located on the underside of the circuit board to the heat sink. A phase change material, a suitable substance capable of absorbing thermal energy, can also be used as thermal paste.

[0022] If the circuit board has at least one opening, access can be provided underneath the circuit board at appropriate locations, for example, to loosen fasteners or access other components of the electronic assembly. A tool can also be positioned through such an opening to loosen the circuit board by sideways sliding of heat sinks, breaking a connection between components and a heat sink in the form of a hardened thermal paste or similar material. This also facilitates disassembly of the circuit board and thus speeds up its replacement or repair.

[0023] The external electronic components can, for example, be formed by chokes, which, due to their higher power class, are located away from the circuit board and are electrically connected to contacts on the circuit board using appropriate cable connections. Larger capacitors, transformers, or power semiconductors are also conceivable as external electronic components.

[0024] For cooling, the chokes can be arranged in so-called choke shells, which are appropriately designed and adapted heat sinks, preferably made of aluminum or aluminum alloys. In addition to cooling the chokes, the choke shells also provide a suitable mechanical support for the chokes. If necessary, the chokes can be placed in the choke shells using thermal paste and, if necessary, additionally secured with fasteners.

[0025] The object of the invention is also achieved by an inverter mentioned above, in particular a photovoltaic inverter, with a power section embodied as an electronic assembly with the aforementioned features. This allows for the realization of an inverter whose components, in particular the power section, can be replaced particularly quickly and easily. This allows the inverters to be repaired more cost-effectively in the event of a defect. For further advantages, please refer to the above description of the electronic assembly.

[0026] The present invention is explained in more detail with reference to the accompanying drawings, which show Fig. 1 schematically shows an electronic assembly with a printed circuit board and an external electronic component according to the prior art; Fig. 2 schematically shows an electronic assembly with a printed circuit board and an external electronic component according to the present invention; Fig. 3 a perspective view of a specially designed housing part with external electronic components arranged therein and a carrier according to the invention for supporting the connection of the external electronic components to a printed circuit board; Fig. 4 a detailed view of the carrier from Fig. 3 from above; Fig. 5 a plan view of an electronic assembly with housing parts with external electronic components, corresponding supports and a heat sink for cooling components, which are placed on the underside of a printed circuit board that can be arranged above it; and Fig. 6 a part of the electronic assembly according to Fig. 5 with a circuit board arranged above it.

[0027] In Fig. 1 is a schematic representation of an electronic assembly 1 with a printed circuit board 2 and an external electronic component 3 according to the prior art. In the sectional view shown, the printed circuit board 2, for example the power electronics of an inverter, is connected to external electronic components 3, for example corresponding chokes, via cables. The connections 4 of the external electronic components 3 are connected to the corresponding contacts 5 on the printed circuit board 2 via fastening screws 18. The printed circuit board 2 is connected, in particular screwed, to the housing part 6 via corresponding fastening elements 11, in particular fastening screws 12. The housing part 6 can simultaneously function as a holder for the external electronic component 3 and can also cool this external electronic component 3 at the same time, in that the housing part 6 is made of metal and has cooling fins or the like at correspondingly suitable locations.to dissipate heat (not shown).

[0028] The manufacture and removal of the screw connections for electrically connecting the terminals 4 of the external electronic components 3 to the contacts 5 on the printed circuit board 2 using the fastening screws 18 is relatively complex and can often only be performed manually. Especially with manufacturing tolerances, it can be particularly difficult to position the fastening screws 18 correctly, which can also lead to the screws becoming jammed, further complicating assembly and disassembly. Consequently, the effort required to repair a defective electronic assembly 1 is relatively high.

[0029] Fig. 2 shows schematically an electronic assembly 1 with a printed circuit board 2 and an external electronic component 3 according to the present invention. According to the invention, a carrier 7 is provided which is displaceably mounted on the housing part 6. The displaceability in at least one direction is illustrated by the horizontally arranged double arrow X next to the carrier 7. The displaceability of the carrier 7 relative to the housing part 6 in at least one direction can be achieved by corresponding elongated holes 10 (see also Fig. 3 and 4) can be easily realized, in which elongated holes 10 suitable fastening elements 11, in particular fastening screws 12, are arranged for fastening to the housing part 6. Holders 8 for receiving contact elements 9 are provided on the carrier 7. The contact elements 9 arranged in the holders 8 of the carrier 7 are connected in a suitable manner to the connections 4 of the external electronic components 3, for example chokes. Furthermore, the contact elements 9 in the holders 8 of the carrier 7 are designed for connection to the contacts 5 on the printed circuit board 2. In the illustrated embodiment, the contact elements 9 are designed as plugs 16 and the contacts 5 on the printed circuit board 2 by correspondingly matching sockets 17. Likewise, the contact elements 9 could also have an internal thread for receiving a screw with a corresponding external thread (not shown).

[0030] During assembly, the carrier 7 is first connected to the external electronic component 3 by arranging the contact elements 9 in the holders 8 provided for this purpose on the carrier 7. The carrier 7 is then provisionally connected to the housing part 6, for example using the fastening screws 12 arranged in the elongated holes 10. A displacement in the direction of the double arrow X is still possible. The printed circuit board 2 is then arranged over the carrier 7. The displaceability of the carrier 7 and the contact elements 9 arranged on it means that certain tolerances can be compensated for and a secure connection of the contact elements 9 to the contacts 5 on the printed circuit board 2 can be quickly made. In the case of a plug-in connection realized by the plugs 16 and sockets 17, the connection of the contact elements 9 orThe external electronic components 3 can be connected to the corresponding contacts 5 on the printed circuit board 2 quickly and without tools, and can also be removed again. When the printed circuit board 2 is connected to the contact elements 9 on the carrier 7, both the carrier 7 and the printed circuit board 2 can be fastened to the housing part 6 using corresponding fastening elements 11, in particular fastening screws 12. If necessary, corresponding openings 24 are arranged in the printed circuit board 2 in order to be able to operate the fastening elements 11, in particular fastening screws 12, possibly arranged underneath, using suitable tools (not shown).

[0031] This results in a simpler and faster attachment and detachment of the circuit board 2 to and from the external electronic components 3, which enables a faster repair or replacement of individual components of the electronic assembly 1.

[0032] In Fig. 3 a perspective view of a specially designed housing part 6 of an electronic assembly 1 with external electronic components 3 arranged therein is shown. Fig. 4 shows a detailed view of the carrier 7 from Fig. 3 from above. For example, the housing part 6 is a choke shell 26 in which chokes 25 as external electronic components 3 are arranged. The choke shell 26 as the housing part 6 has spaces for the arrangement of the chokes 25, which are separated from one another by webs 27. The choke shell 26 is preferably made of metal, in particular aluminum or an aluminum alloy, thereby ensuring cooling of the external electronic components 3. A seal 28 can be arranged on the edge of the choke shell 26. Above the chokes 25, the carrier 7 according to the invention is arranged to support the connection of the chokes 25 as external electronic components 3 to a printed circuit board 2 (not shown). The carrier 7 is slidably mounted on the choke shell 26. For this purpose, elongated holes 10 for receiving corresponding fastening screws 12 are provided on the carrier 7 (see detail in Fig. 4 ), which fastening screws 12 can be screwed into the threads provided in the webs 27 of the throttle shell 26. The elongated holes 10 allow a displacement of the carrier 7 relative to the throttle shell 26 in one direction, the longitudinal axis of the elongated hole 10 along the double arrow X. A locking lug 13 can be arranged in the elongated hole 10 to determine a preferred position for the fastening element 11, in particular the fastening screw 12 (see Fig. 4 ). When the support 7 is moved in the direction of the double arrow X, a small resistance must be overcome by the locking lug 13.

[0033] The carrier 7 has holders 8 for receiving contact elements 9, which are connected to the terminals 4 of the external electronic components 3. Furthermore, the contact elements 9 arranged in the holders 8 of the carrier 7 serve to establish the connection with corresponding contacts 5 on the printed circuit board 2 (not shown). In the illustrated embodiment, the contact elements 9 are formed by plugs 16, which can be connected to complementarily designed sockets 17 on the printed circuit board 2 (not shown).

[0034] The carrier 7 is preferably made of plastic, for example polyamide. This ensures ease of manufacture and, on the other hand, achieves the necessary electrical insulation of the contact elements 9 arranged in the holders 8. If the carrier 7 is designed as a grid, material and thus weight can be saved and access to the components arranged beneath the carrier, for example the external electronic components 3 or chokes 25, is enabled. At least one centering pin 14 can be arranged on the carrier 7, which can be arranged in a corresponding centering opening 15 on the printed circuit board 2 (see Fig. 6 ). The centering pin 14, like the elongated holes 10 and the holders 8 for the contact elements 9, can preferably be easily formed in a manufacturing process of the carrier 7, for example an injection molding process.

[0035] Fig. 5 is a plan view of an electronic assembly 1 with housing parts 6 with external electronic components 3, corresponding carriers 7 and a heat sink 21 for cooling components 22, which are arranged on the underside of a printed circuit board 2 (see Fig. 6 ) are placed. The electronic assembly 1 is, for example, the power section of an inverter, in particular a photovoltaic inverter, which serves to convert the direct voltage generated by photovoltaic modules into an alternating voltage. The housing or the housing part 6 of the inverter contains two choke shells 26 for the DC-side power section and the AC-side power section of the inverter, in which the external electronic components 3 are arranged in the form of chokes 25. Four chokes 25 are arranged in the left-hand DC-side power section, while three chokes 25 are placed in the right-hand AC-side power section. According to the invention, supports 7 are provided in each case, which are mounted on the housing part 6 so as to be displaceable (double arrows X). The displaceable mounting is achieved by the elongated holes 10.The grid-like supports 7 have holders 8 for receiving the contact elements 9 for connection to the terminals 4 (not shown) of the external chokes 25. A heat sink 21 made of a suitable material is arranged between the choke shells 26 of the DC-side and AC-side power section of the inverter. This heat sink 21 serves to cool electronic components 22 (indicated by dashed areas) arranged on the underside of the printed circuit board 2, which is attached above the choke shells 25 (see ). Fig. 6 ).

[0036] Fig. 6 shows a part of the electronic assembly 1 according to Fig. 5with the printed circuit board 2 arranged above it. When the printed circuit board 2 is placed above the carrier 7 of the choke shell 25, contact is made with the contact elements 9. In the illustrated embodiment, the contact elements 9 are formed by plugs 16 which fit into corresponding sockets 17 on the printed circuit board 2 in order to achieve an electrical connection between the external chokes 26 and the conductor tracks on the printed circuit board 2.

[0037] To improve heat conduction, a thermal paste 23 is preferably applied between the components 22 and the heat sink 21. This thermal paste 23, which can be formed from a phase change material, usually hardens, making disassembly of the printed circuit board 2 more difficult. Here, the movable mounting of the carrier 7 offers a further advantage in addition to compensating for tolerances. After loosening various fastening screws 12, with which the printed circuit board 2 and the carriers 7 are fixed to the housing part 6 (not shown), the thermal paste 23 between the components 22 and the heat sink 21 can be loosened by moving it in the direction of the double arrow X, and thus the printed circuit board 2 with the components 22 can be detached from the heat sink 21.To support the movement, openings 24 can be arranged in the circuit board 2, into which appropriate tools, such as screwdrivers, can be inserted in order to move the circuit board 2.

[0038] Centering pins 14 on the carrier 7 can also be seen, which protrude into corresponding centering openings 15 on the circuit board 2.

[0039] The present invention facilitates the connection of the printed circuit board 2 with external electronic components 3 and thus simplifies assembly and disassembly of components of the electronic assembly 1. In particular, in the case of inverters with assemblies designed in this way, repair is made considerably easier and costs can thus be reduced.

[0040] An application in other circuits, such as welding machines or battery chargers, is of course also possible and useful.

Claims

1. Electronic assembly (1) with at least one circuit board (2) and external electronic components (3) with electrical connections (4), wherein the circuit board (2) comprises contacts (5) for connection to the connections (4) of the external electronic components (3), and the at least one circuit board (2) and the external components (3) are able to be attached to a housing part (6), characterised in that a carrier (7) that is mounted so as to be able to be moved is provided on the housing part (6), wherein the carrier (7) comprises holders (8) for receiving contact elements (9) for connection to the connections (4) of the external electronic components (3) and for connection to the contacts (5) on the circuit board (2).

2. Electronic assembly (1) according to claim 1, characterised in that the carrier (7) is mounted so as to be able to be moved in one direction.

3. Electronic assembly (1) according to claim 2, characterised in that the carrier (7) comprises at least one elongated hole (10) for receiving a fastening element (11), in particular a fastening screw (12), which fastening element (11) can be connected to the housing part (6).

4. Electronic assembly (1) according to claim 3, characterised in that a latching lug (13) for fixing a preferred position for the fastening element (11) is arranged in at least one elongated hole (10).

5. Electronic assembly (1) according to one of claims 1 to 4, characterised in that the carrier (7) is formed from plastic, for example from polyamide.

6. Electronic assembly (1) according to one of claims 1 to 5, characterised in that the carrier (7) is designed as a grid.

7. Electronic assembly (1) according to one of claims 1 to 6, characterised in that at least one centring pin (14) is arranged on the carrier (7), which centring pin can be arranged in a corresponding centring opening (15) on the circuit board (2).

8. Electronic assembly (1) according to one of claims 1 to 7, characterised in that the contact element (9) is formed by a plug (16) which can be connected to a socket (17) of complementary design on the circuit board (2).

9. Electronic assembly (1) according to one of claims 1 to 8, characterised in that a heat sink (21) is arranged on the housing part (6), which heat sink (21) can be contacted with components (22) arranged on the underside of the circuit board (2).

10. Electronic assembly (1) according to one of claims 1 to 9, characterised in that a heat-conducting paste (23) can be arranged between the components (22) and the heat sink (21).

11. Electronic assembly (1) according to one of claims 1 to 10, characterised in that the circuit board (2) comprises at least one opening (24).

12. Electronic assembly (1) according to one of the claims 1 to 11, characterised in that the external electronic components (3) are formed by chokes (25).

13. Electronic assembly (1) according to claim 12, characterised in that the chokes (25) are arranged in choke shells (26).

14. Inverter, in particular photovoltaic inverter, with a power section, characterised in that the power section is designed as an electronic assembly (1) according to one of claims 1 to 13.