Arrangement and method for electrically and mechanically connecting a printed circuit board

Abstract

Arrangement for electrically and mechanically connecting a printed circuit board (1) to a first component (2) which is smaller in terms of the dimensions of the printed circuit board (1), wherein the first component (2) is attached to at least a second component (3), wherein at least one frame element (4) is detachably attached to the printed circuit board (1) for mechanical stabilization, wherein the part of the printed circuit board (1) projecting beyond the first component (2) is attached to the second component (3) via at least one flexible element (5) for tolerance compensation, and wherein the frame element (4) is removable from the printed circuit board (1) after the printed circuit board (1) has been attached to the first component (2) and the second component (3).

Description

[0001] The present invention relates to an arrangement and a method for electrically and mechanically connecting a printed circuit board.

[0002] For example, it is known from automotive technology to connect circuit boards with electronic components electrically or electronically and mechanically. Screw connections are usually used for this purpose. However, if the circuit board is connected to components whose dimensions are smaller than the circuit board itself, the circuit board protrudes over the electronic components. This means that there is a risk that the circuit board will be subjected to mechanical stress when screwed together. This can cause damage to solder joints or similar on the circuit board. A further problem arises that, due to high tolerances in production, for example in injection-molded housings, sufficient fastening is not possible. This can lead to unwanted vibrations on the circuit board. This in turn can lead to damage to the circuit board.

[0003] A printed circuit board holding device is known from DE 10 2009 045 915 A1. The printed circuit board holding device comprises several clamping elements, between which the printed circuit board is held in a housing-like manner. Elastic sections are located between the clamping elements and the printed circuit board, enabling tolerance compensation. In the known printed circuit board holding device, the installation space requirement is disadvantageously increased by the housing-like clamping elements surrounding the printed circuit board. Consequently, attaching the printed circuit board directly to an electronic component with the printed circuit board holding device is not possible.

[0004] From the publication US 2006 / 0 077 642 A1, a fastening of printed circuit boards in housings of portable electronic devices and a method for fastening a system board in a laptop computer are known. The device comprises a hole in the printed circuit board, a pair of spaced-apart mounting pads in the housing, a rigid column, and a first elastic spring washer. The rigid column extends through the hole in the board between the mounting pads in the housing. The first elastic spring washer is arranged between a first mounting pad in the spaced-apart mounting pads and a first side of the printed circuit board.

[0005] The present invention is based on the object of proposing an arrangement and a method for electrical and mechanical connection which enables a secure and tolerance-compensated connection of the printed circuit board to components.

[0006] This object is achieved according to the invention by the features of patent claim 1 or 9, whereby advantageous embodiments result from the respective subclaims and the description as well as the drawings.

[0007] Accordingly, an arrangement for electrically mechanically connecting a printed circuit board to a first component which is smaller in terms of the dimensions of the printed circuit board is proposed, wherein the first component is fastened to at least one second component.

[0008] In order to realize a sufficiently mechanically stable and tolerance-compensating connection of the circuit board to the components, it is provided that at least one frame element is detachably fastened to the circuit board for mechanical stabilization and that the part of the circuit board projecting beyond the first component is fastened to the second component via at least one flexible element for tolerance compensation.

[0009] To connect or mount the circuit board, a frame is used in which the circuit board is joined linearly to the component to be connected with evenly distributed force, without causing undesired bending of the circuit board. The final position of the circuit board is reached when the protruding part of the circuit board rests on the flexible elements for fastening the circuit board on the screw bosses of the first component. The flexible or compressible elements below the area of ​​the circuit board that protrudes beyond the first component allow for tolerance compensation when fastening the circuit board.

[0010] The arrangement according to the invention enables electrical or electronic and mechanical connection of the circuit board to any components, such as housing parts, electronic components, or the like. A preferred application of the arrangement according to the invention can be for attaching the circuit board to a power module, for example, an electrical machine or the like in a vehicle transmission.

[0011] Any compressible, elastic element, such as rubber rings, springs, disc springs, or the like, can be used as flexible elements. A pressure frame can preferably be used as the frame element to mechanically stabilize the circuit board. The pressure frame can, for example, be designed in several parts to allow the pressure chamber to be removed from the circuit board after the circuit board has been installed. Single-part designs are also conceivable, allowing for detachable fastening, for example, through latches or the like.

[0012] The object underlying the invention is also achieved by a method for the electrical and mechanical connection or assembly of a printed circuit board to a first component which is smaller in terms of the dimensions of the printed circuit board and which is fastened to at least one second component. In the assembly method according to the invention, the printed circuit board is first provided with a frame for mechanical stabilization. The printed circuit board is then aligned above the first component and joined to it in a linear manner and screwed. The part of the printed circuit board which protrudes beyond the first component is then fastened with fastening screws, for example, via flexible elements to compensate for tolerances. The frame is removed from the printed circuit board again after the printed circuit board has been fastened to the first component and the second component.

[0013] In an advantageous embodiment of the invention, tolerance-free and stress-free assembly of the circuit board is achieved by compressing the flexible elements when the circuit board is pressed down, and then screwing the fastening screws fully into the associated screw bosses without further compressing the flexible elements. This secures the tolerance-free and stress-free fastening position.

[0014] The present invention is further explained below with reference to the drawings. They show: Fig. 1 an exploded view of an arrangement according to the invention for electrically and mechanically connecting a printed circuit board; Fig. 2 a plan view of the arrangement according to Fig. 1; Fig. 3 a sectional view along the section line AA according to Fig. 2 with the circuit board not yet mounted; Fig. 4 a three-dimensional schematic view of the arrangement in the assembled state of the circuit board; Fig. 5 a sectional view along section line AA in the assembled state of the circuit board; Fig. 6 a schematic three-dimensional view of the arrangement after removal of the frame element; and Fig. 7 a sectional view along section line AA after removal of the frame element.

[0015] In the Fig. Figures 1 to 7 show various views of an arrangement according to the invention for electrically and mechanically connecting a printed circuit board 1. The various views also illustrate the method according to the invention for electrically and mechanically connecting the printed circuit board 1.

[0016] The arrangement according to the invention serves for the electrical and mechanical connection of the printed circuit board 1 to a first component that is smaller in terms of the dimensions of the printed circuit board 1 and is preferably a power electronics unit or a power module 2. The first component or the power module 2 is attached to a second component, which is preferably a housing 3. The printed circuit board 1 is mechanically attached to the first component or the power module 2 via screw connections 7.

[0017] According to the invention, a frame element 4 is detachably attached to the circuit board 1 for mechanical stabilization. The part of the circuit board 1 projecting beyond the power module 2 is attached to the housing 3 via several flexible elements 5 for tolerance compensation.

[0018] The power module 2, which is designed, for example, as an injection-molded housing, is fastened in or on the housing 3, with the printed circuit board 1 being electrically and mechanically fastened to the power module 2. The part of the printed circuit board 1 protruding beyond the power module 2 is mechanically fastened via the flexible elements 5, each with an associated screw dome 6 of the housing 3, using fastening screws 8. The screw dome 6 essentially forms the internal thread for the associated fastening screw 8 and can be made of plastic or metal. With screw domes 6 made of metal, there is the advantage that, even if the flexible elements 5 are made of metal or of an electrically conductive material, such as metal springs or the like, the connection to the housing 3 simultaneously establishes the ground connection between the printed circuit board 1 and the housing 3.

[0019] In order to achieve the compressed or elastic effect for tolerance compensation, the elastic or flexible elements 5 can also be designed as rubber rings or disc springs or the like.

[0020] As can be seen from the figures, a screw boss 6 is assigned to each corner area of ​​the protruding part of the circuit board 1. To attach the circuit board 1 to the power module 2, several screw connections 7 are provided, which secure the circuit board 1 with its underside to the power module 2.

[0021] The frame element 4 provided for mechanical stabilization is designed as a pressure frame surrounding the circuit board 1 and can be removed from the circuit board 1 again after the circuit board 1 has been attached to the power module 2 or to the housing 3.

[0022] For assembly of the Fig. 1 as an exploded view, a method is also proposed for the electrical and mechanical connection of the printed circuit board 1 to the first component or power module 2, which is smaller in terms of the dimensions of the printed circuit board 1, wherein the power module 2 is fastened to the second component or to the housing 3. To assemble the printed circuit board 1 connected to the frame element 4, it is joined linearly to the power module 2 with uniformly distributed force, without bending the printed circuit board 1. The final position of the printed circuit board 1 is reached when the printed circuit board 1 rests on the screw bosses 6 of the power module 2, as shown, for example, in the Fig. 4 to 7. The circuit board 1 is attached to the power module 2 via the screw connections 7.

[0023] Below the holes for screwing the part of the printed circuit board 1 projecting over the power module 2 to the housing 3, there are compressible flexible elements 5 on the associated screw bosses 6 of the housing 3. When the printed circuit board 1 is pressed down to the end position, the flexible elements 5 are compressed and a force is generated in the direction of the printed circuit board 1, as shown in particular in Fig. 5 shown.

[0024] To fasten the printed circuit board 1 to the housing 3, metric fastening screws 8, for example with washers 9, are used for screwing into the respective screw boss 6 of the housing 3. The fastening screws 8 are screwed in until they stop, without further compressing the flexible elements 5. After the screwing process is complete, the frame element 4 is removed again, as shown in Fig. 6. The printed circuit board 1 is held in the non-tensioned position by the fastening screws 8 and the resilient or flexible elements 5, which is particularly Fig. 7 becomes clear. Reference symbol 1 circuit board 2 first component or power module 3 second component or housing 4 frame element 5 flexible element 6 screw dome 7 Screw connection 8 fixing screw 9 Washer

Claims

[1] Arrangement for the electrical and mechanical connection of a printed circuit board (1) to a first component (2) which is smaller in terms of the dimensions of the printed circuit board (1), wherein the first component (2) is fastened to at least one second component (3), wherein at least one frame element (4) is detachably fastened to the printed circuit board (1) for mechanical stabilization, wherein the part of the printed circuit board (1) projecting beyond the first component (2) is fastened to the second component (3) via at least one flexible element (5) for tolerance compensation, and wherein the frame element (4) is removable from the printed circuit board (1) after the printed circuit board (1) has been fastened to the first component (2) and the second component (3). [2] Arrangement according to claim 1, characterized bythat a power module (2) is fastened as the first component to a housing (3) provided as the second component, wherein the printed circuit board (1) is electrically and mechanically fastened to the power module (2) protruding from the housing (3), and that a part of the printed circuit board (1) protruding beyond the power module (2) is fastened in an associated screw dome (6) of the housing (3) via at least one flexible element (5) and at least one fastening screw (8). [3] Arrangement according to claim 2, characterized by that a rubber ring and / or a spring element is provided as a flexible element (5) between the associated screw dome (6) and the underside of the printed circuit board (1). [4] Arrangement according to one of claims 2 or 3, characterized by that the corner areas of the protruding part of the circuit board (1) are each assigned a screw dome (6). [5] Arrangement according to one of claims 2 to 4, characterized bythat the fastening screw (8) with the flexible element (5) and the associated screw dome (6) are made of an electrically conductive material as a ground connection of the printed circuit board (1). [6] Arrangement according to one of claims 2 to 5, characterized by that the part of the circuit board (1) provided above the power module (2) is connected to the power module (2) via several screw connections (7). [7] Arrangement according to one of the preceding claims, characterized by that the frame element (4) is designed as a pressure frame surrounding the circuit board (1). [8] Arrangement according to one of the preceding claims, characterized by that the frame element (4) is made up of several parts. [9] Method for electrically and mechanically connecting a printed circuit board (1) to a first component (2) which is smaller in terms of the dimensions of the printed circuit board (1) and which is fastened to at least one second component (3), characterized bythat the printed circuit board (1) is provided with a frame element (4) for mechanical stabilization, that the printed circuit board (1) is aligned above the first component (2) and screwed to it, that the part of the printed circuit board (1) protruding beyond the first component (2) is fastened via flexible elements (5) for tolerance compensation, and that after the printed circuit board (1) has been fastened to the first component (2) and the second component (3), the frame element (4) is removed. [10] Method according to claim 9, characterized by that when the printed circuit board (1) is pressed down, the flexible elements (5) are compressed and that the fastening screws (8) are screwed into the associated screw domes (6) as far as they will go without further compressing the flexible elements (5).

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