Contact element, circuit board and system with circuit board and card edge connector

Abstract

The present invention relates to aspects of the production of an electrical connection between an electrical conductor and a circuit board.To present a solution that allows card edge connectors to be used even in areas with dynamic mechanical stress without having to accept contact failures, and / or to allow a card edge connector to be used for a larger span of printed circuit board, a contact element is proposed which is designed to be applied to a contact pad of a printed circuit board for contact transmission, wherein the contact element is essentially plate-shaped, has a fixing area, a blocking area and a contacting area in the longitudinal direction and has a cross-sectional reduction in the blocking area arranged between the fixing area and the contacting area, wherein the fixing area is designed for contacting the contact pad and the contacting area is designed for contacting an electrical contact of a card edge connector.

Description

[0001] The present invention relates to aspects of producing an electrical connection between an electrical conductor and a printed circuit board, and in particular a contact element configured to be applied to a contact pad of a printed circuit board for contact transmission, a printed circuit board for contacting with a card edge connector, a contact element arrangement for a printed circuit board for contacting with a card edge connector, and a method for producing a printed circuit board for contacting with a card edge connector, as well as a system comprising a printed circuit board and a card edge connector configured for contacting with the printed circuit board, and a method for providing such a system.

[0002] Connectors or plug-in devices are generally used to disconnect and connect conductors, especially conductors intended for carrying electrical current, for example for power and / or signal transmission. A connector or plug-in device can have a corresponding mating connector or mating device.

[0003] On the other hand, connectors or plug-in devices are also known that are designed to connect one or more electrical conductors directly (i.e., without involving a mating connector or plug-in device) to a printed circuit board, such as a printed circuit board (PCB). Such connectors or plug-in devices are also referred to as card edge connectors (hereinafter, the term card edge connector also refers to a card edge plug-in device unless otherwise indicated by the context), wherein the electrical contacts of the printed circuit board are located in the region of an edge of the printed circuit board and the card edge connector encompasses this edge, so that the contacts of the card edge connector are electrically connected to contacts of the printed circuit board.

[0004] Card edge connectors are disclosed, for example, in DE 10 2013 110 082 A1 and WO 2016 / 110279 A1.

[0005] DE 10 2013 110 082 A1 relates to a connector for establishing an electrical connection between an electrical conductor and a printed circuit board. The connector comprises an insulating body with several cavities for receiving contact elements. The printed circuit board can be inserted into the connector via a slot in one mating side of the insulating body and made contact with the first contact surfaces of the contact elements provided in that mating side. Opposite the first contact surface, the contact elements have a second contact surface, which is designed for making insulation-penetrating contact with the electrical conductor. The arrangement of the contact elements within the insulating body allows for a particularly compact design of the connector.

[0006] WO 2016 / 110279 A1 describes a card edge connector for electrically contacting a printed circuit board at its edge. The card edge connector has special features for secure potting or overmolding. It consists of an insulating body with electrical contacts arranged within it. One contact side of the insulating body has a slot for receiving the printed circuit board and is equipped with a cover. The cover seals the interface between the card edge connector and the printed circuit board. This seal prevents material ingress during potting or overmolding of the card edge connector.

[0007] While contacting at the card edge is advantageous in that it eliminates the need for a mating connector that would otherwise have to be applied to the circuit board, known card edge connectors have a problem in that contact failures or contact errors can occur over time, especially in areas with dynamic mechanical stress (vibrations, shocks, etc., but also a high number of mating cycles).

[0008] Another limitation of the known approaches is that the card edge connector and the circuit board must be matched, since the known card connectors are each designed for a circuit board with a predetermined material thickness within a relatively small tolerance range.

[0009] One objective underlying the present invention is to improve the usability of card edge connectors.

[0010] It is therefore desirable to present a solution that, in particular, allows card edge connectors to be used even in areas with dynamic mechanical stress without having to accept contact failures, and / or that, in particular, allows a card edge connector to be used for a larger range of printed circuit boards.

[0011] According to a first aspect of the invention, a contact element is proposed which is designed to be applied to a contact pad of a printed circuit board for the purpose of transmitting a contact, as defined in claim 1, wherein the contact element is essentially plate-shaped, has a fixing area, a blocking area and a contacting area in the longitudinal direction and has a reduction in cross-section in the blocking area arranged between the fixing area and the contacting area, wherein the fixing area is designed for contacting the contact pad and the contacting area is designed for contacting an electrical contact of a card edge connector.

[0012] According to a second aspect of the invention, a printed circuit board for contacting a card edge connector is proposed, as defined in claim 7, namely with a plurality of electrical contacts arranged in the region of an edge of the printed circuit board, each of which is connected to a plurality of electrical conductors of the printed circuit board, wherein each electrical contact has a contact pad connected to the corresponding electrical conductor and a plate-shaped contact element applied to the contact pad in a contacting manner, which is configured for contacting an electrical contact of the card edge connector. In particular, each electrical contact has a contact element according to the invention.

[0013] According to a third aspect of the invention, a contact element arrangement for a printed circuit board according to the invention is proposed for contacting a card edge connector, as defined in claim 11, namely with several plate-shaped contact elements, each designed for contacting an electrical contact of the card edge connector, in particular contact elements according to the invention, wherein the several contact elements are received in a common receptacle, wherein the receptacle preferably has at least one positioning element which allows a predetermined relative positioning of the receptacle and the printed circuit board when the contact elements are applied to the printed circuit board provided with a corresponding positioning element.

[0014] According to a fourth aspect of the invention, a method for manufacturing a printed circuit board for contacting a card edge connector is proposed, as defined in claim 14, namely comprising the steps of providing a printed circuit board with a plurality of contact pads arranged in the region of an edge of the printed circuit board, each of which is connected to a plurality of electrical conductors of the printed circuit board, providing a plurality of plate-shaped contact elements, in particular contact elements according to the invention, and contacting the plurality of plate-shaped contact elements onto a respective contact pad, so that the contact elements are configured for contacting respective electrical contacts of the card edge connector.

[0015] Another aspect of the invention provides a system comprising a printed circuit board according to the invention and a card edge connector configured for contacting the printed circuit board. A further aspect of the invention provides a method for providing such a system comprising the steps of the inventive method for manufacturing a printed circuit board and the further step of providing a card edge connector, wherein providing the plurality of plate-shaped contact elements comprises selecting plate-shaped contact elements with a material thickness determined based on the material thickness of the printed circuit board and a dimension of the card edge connector, or providing the card edge connector comprises selecting a card edge connector with a dimension determined based on the material thickness of the printed circuit board and a material thickness of a contact element.

[0016] Part of the background of the present invention can be found in the following considerations.

[0017] It has been recognized that one factor contributing to contact failures or faults in edge-of-circuit connectors under dynamic mechanical stress is that the connector contacts wear down the conductive surface of the circuit board's contact pads through abrasion or scratching. A high number of mating cycles, as well as relative movement between the contact and contact pad caused by vibrations or repeated shocks, leads to material loss in the contact pad. A further factor is that the edge-of-circuit connector contacts must exert a significant contact force on the contact pads to prevent them from lifting off the pad during vibrations or shocks, which would result in a loss of contact.The risk of detachment can be reduced by designing the contacts of the card edge connector for contacting opposing contact pads, as shown in DE 10 2013 110 082A1 and WO 2016 / 110279 A1. However, sufficient contact force is still necessary.

[0018] Increasing the overall material thickness of a circuit board's contact pad by increasing the overall thickness of the conductor tracks is uneconomical. Furthermore, the approach of applying additional material to the contact pads, such as gold plating (possibly with an intermediate nickel layer), to achieve higher resistance to abrasion is comparatively costly.

[0019] It was recognized that an additional contact element can be attached to the contact pad of a circuit board in a relatively simple manner, and that this contact element can also be specifically designed so that the otherwise occurring material removal does not lead to a loss of contact.

[0020] Using well-known pick-and-place machines, the contact elements can be placed on the circuit board quickly and reliably.

[0021] Since only a comparatively small tolerance can be compensated for by a necessarily elastic deformation of the contact in the size range of contacts of a card edge connector, it is necessary to closely match conventional card edge connectors and conventional printed circuit boards when combining them.

[0022] It was recognized that it is possible to adapt otherwise essentially unchanged printed circuit boards with different material thicknesses to approximately only one size of card edge connector by selecting the material thickness of the contact pads of the printed circuit board based on the material thickness of the printed circuit board and the size of the card edge connector.

[0023] Applying a contact element to the contact pad of a printed circuit board can be done by, for example, applying solder paste to the contact pad (and / or the contact element's fixing area). It has been observed that during fixing (i.e., soldering) the contact element, solder paste and / or liquid solder can migrate from the area between the contact pad and the fixing area to the contact area, for example, due to capillary forces. This additional material on the top surface of the contact area can then have detrimental effects on the contact. By providing a barrier area with a reduction in cross-section, the forces that would otherwise draw the solder or paste to the contact area can be specifically controlled.In this way, a known technique for applying solder paste in the area of ​​pick-and-place machines can be used without the need to go to great lengths to try to keep the amount of solder paste applied within a certain range, in order to achieve a secure connection between the contact pad and the contact element on the one hand, and to prevent the contact area from being contaminated by excess material on the other.

[0024] In an advantageous embodiment of an aspect of the invention, the contact element has a top surface and a bottom surface opposite the top surface, wherein the surface of the locking area in the area of ​​the top surface and / or the bottom surface is recessed relative to that of the fixing area and / or that of the contacting area, in particular in the form of a respective notch, and / or wherein the contact element has a first side surface and a second side surface opposite the first side surface, which extend in the longitudinal direction, wherein the surface of the locking area in the area of ​​at least one side surface is recessed relative to that of the fixing area and / or that of the contacting area, in particular in the form of a waist.

[0025] It was found that the cross-sectional reductions in the direction from top to bottom or laterally perpendicular to the longitudinal direction of the contact element each provide a blocking effect on their own, which can be further increased by the combination.

[0026] In another advantageous embodiment of an aspect of the invention, the barrier area is designed to reduce or prevent the transfer of solder and / or electrically conductive adhesive to the contact area, in particular to a top surface of the contact area, when the fixing area is soldered and / or glued to the contact pad.

[0027] Particularly in the case of soldering or gluing, a flowable material is present at least temporarily, the migration of which to the top of the contact area should be prevented if possible.

[0028] In another advantageous embodiment of an aspect of the invention, the contact element comprises a core, preferably an electrically conductive core, in particular made of copper, nickel, a copper alloy or a nickel alloy, and at least one electrically conductive coating applied to the core, preferably made of gold or palladium, wherein the electrically conductive coating on a bottom side of the fixing area and the electrically conductive coating on a top side of the contacting area are in electrical contact with each other.

[0029] It is not necessarily the case that the entire contact element must be conductive. It is quite possible that the contact element has a non-conductive core, e.g. made of a suitable plastic, onto which electrically conductive coatings are applied, at least in the relevant areas.

[0030] The design of the contact element, with a core and a conductive coating, allows for a more precise selection of the materials used. For example, gold can be chosen as the coating material based on its contact properties and corrosion resistance, while the core can utilize nickel, a material with lower costs and better machinability.

[0031] As an alternative to designing the contact element with a core and a coating applied thereto, the contact element can also, according to the invention, consist (at least substantially) of only an electrically conductive material. It has been found that particularly good properties are achieved with a contact element made of a copper-nickel-zinc alloy (e.g., nickel silver), and it is also advantageous that the contact element does not require a coating or any other surface treatment. Furthermore, it has been found that it is advantageous if the contact pad is also made of the same material used for the contact element.

[0032] In another advantageous embodiment of an aspect of the invention, the contact element or core is punched out, wherein the upper side provided for contacting with the electrical contact of the card edge connector is preferably the insertion side.

[0033] During die-cutting, the material is typically partially cut and partially torn or broken. On the feed side, where the cutting action of the die-cutting tool occurs, there is usually a relatively smooth and flat edge, possibly even a slightly chamfered one. On the burr side, there is generally an irregularly shaped burr resulting from the breaking or tearing at the end of the die-cutting process. It was recognized that the feed side can be advantageously used for contacting the card edge connector. It was found that the advantages of using the feed side for contacting the card edge connector outweigh any potential disadvantages (e.g., increased risk of gradual cracking in the solder joint) that may be associated with the burr side facing the solder (or adhesive) joint.

[0034] The reduction in cross-section in the blocking area of ​​the contact element can advantageously be incorporated into this punching process; for example, the waisting can be included in the cut of the outer contour and then does not need to be added subsequently after punching a blank for the contact element. The recess relative to the bottom and / or top surface, for example in the form of a notch, is preferably introduced before the first punching cut to minimize distortion.

[0035] In another advantageous embodiment of an aspect of the invention, the contact element has a material thickness of 0.1 mm or more and 1.0 mm or less, in particular 0.5 mm or less.

[0036] An advantageous embodiment of an aspect of the invention relates to a printed circuit board, wherein all of the plurality of contact elements each have a material thickness which lies within a tolerance range of + / - 0.01 mm, preferably + / - 0.005 mm, around a mean material thickness, and / or the printed circuit board including the contact elements in the areas of all contact elements each has a material thickness which lies within a tolerance range of + / - 10% of the material thickness of the printed circuit board around a mean material thickness.

[0037] In another advantageous embodiment of an aspect of the invention, the plurality of electrical contacts of the circuit board comprises a first plurality of first electrical contacts on a first side of the circuit board and a second plurality of second electrical contacts on a second side of the circuit board opposite the first side, wherein preferably one of the first plurality of first electrical contacts is coincidentally opposite a corresponding one of the second plurality of second electrical contacts and, in particular, the first electrical contact and the corresponding second electrical contact are connected to a common electrical conductor of the circuit board.

[0038] With opposing contacts on the circuit board, a contact of the card edge connector can contact a contact from both sides (i.e., from "top" and "bottom"), which leads to better contacting if shocks or vibrations are expected that could temporarily disable one-sided contacting.

[0039] In another advantageous embodiment of an aspect of the invention, several of the contact elements are received in a common receptacle, wherein preferably the receptacle and the circuit board have respective, mutually corresponding positioning elements which allow a predetermined relative positioning of the receptacle and the circuit board when the contact elements are applied.

[0040] The joint provision of several contact elements in one receptacle reduces the effort required to place the contact elements on the circuit board, while the optional positioning elements are helpful in positioning the multiple contact elements in the correct position relative to the respective contact pads.

[0041] In another advantageous embodiment of an aspect of the invention, the circuit board has a coating, in particular a coating of solder resist, wherein the coating has a gap in the area of ​​at least one electrical contact in which the contact element is at least partially received.

[0042] It was found that providing a recess in a coating of the circuit board, such as in the solder mask, can be used to form a receptacle for the contact element, which has the advantage that this receptacle supports correct positioning and alignment of the contact element.

[0043] Features of advantageous embodiments of the invention are defined in particular in the dependent claims, with further advantageous features, embodiments and configurations also being apparent to the person skilled in the art from the above explanation and the following discussion.

[0044] The present invention will now be further illustrated and explained with reference to exemplary embodiments shown in the figures. Here, Fig. 1 a schematic representation of a circuit board with contact elements according to the invention in an exploded view, Fig. 2. The representation of a circuit board with contact elements according to the invention from a opposite Fig. 1. A slightly different perspective, Fig. 3 a schematic representation of an embodiment of a printed circuit board according to the invention with contact elements according to the invention attached thereon, Fig. 4 a schematic representation of a further embodiment of the circuit board according to the invention with a card edge connector attached to it Fig. 5 the circuit board and the card edge connector Fig. 5, which are separate from each other, Fig. 6 the ladder map from the Fig. 4 and Fig. 5 from a different perspective, Fig. 7 the ladder map from the Fig. 4, Fig. 5 and Fig. 6 in an exploded view, Fig. 8 a third embodiment of the circuit board according to the invention with an attached card edge connector, which is equipped with an embodiment of a contact element arrangement, Fig. 9 the circuit board and the card edge connector Fig. 8, which are separate from each other, Fig. 10 the ladder map from the Fig. 8 and Fig. 9 from a different perspective, Fig. Figure 11 shows the circuit board and the contact element arrangements in an exploded view. Fig. 12 a schematic representation of an embodiment of a “thin” printed circuit board with a card edge connector, Fig. 13 a schematic representation of an embodiment of a “thick” circuit board with the card edge connector made of Fig. 12 and Fig. 14 a schematic flowchart of an embodiment of the inventive method for providing a system with a circuit board according to the invention and a corresponding card edge connector.

[0045] In the accompanying drawings and the explanations relating to these drawings, corresponding or related elements are marked with corresponding or similar reference symbols, where appropriate, even if they are found in different embodiments.

[0046] The Fig. Figures 1 to 3 show schematic representations to illustrate a first embodiment of contact elements according to the invention and a first embodiment of a printed circuit board according to the invention.

[0047] Fig. Figure 1 shows a schematic representation of a circuit board with contact elements according to the invention in an exploded view. Fig. Figure 2 shows a representation of a circuit board with contact elements according to the invention from a opposite Fig. 1. A slightly different perspective. Fig. Figure 3 shows a schematic representation of an embodiment of a printed circuit board according to the invention with contact elements according to the invention attached thereon.

[0048] The circuit board 10, shown schematically here without further features such as components, conductor tracks, or the like, has a coating 12 of solder mask on both its top and bottom surfaces. The solder mask coating 12 has gaps 16 in the area of ​​the contact pads 14 located on the circuit board 10, so that the contact pads 14 and an adjacent area are exposed. In the illustration of the Fig. 1 and Fig. In Figure 2, only the top side of the circuit board 10 is visible, although the underside is designed accordingly in this embodiment. While contact on both sides of the circuit board 10 is advantageous, it is also possible for each contact pad 14 to have no counterpart on the opposite side.

[0049] The contact pads 14 are connected to electrical lines of the circuit board 10, which are not shown here.

[0050] In the present embodiment, a slot 18 extends into the circuit board 10 in the area between the contact pads 14, this slot 18 serving for alignment with a card edge connector which is inserted into the Fig. 1 to 3 are not shown. The meaning of slot 18 can be determined from the Fig. 4, Fig. 5, Fig. 8 and Fig. 9 and its subsequent discussion. Instead of providing a slot 18 (or several slots), other means for mutual alignment may be provided, which are known to those skilled in the art with circuit board edge connectors. In some circumstances, separate means for aligning the circuit board and circuit board edge connector on these components themselves may be dispensed with, particularly if these components are already sufficiently aligned with each other by other components.

[0051] In the present embodiment, four contact pads 14 and corresponding four contact elements 20 are provided, although of course the invention is not limited in this respect.

[0052] The contact elements 20, which are located in the Fig. 1 and Fig. 2, which are shown separately from the circuit board 10, are each essentially designed in a plate-like form and comprise a fixing area 22, a blocking area 24 and a contacting area 26.

[0053] The fixing area 22 serves for electrical contact with a respective contact pad 14 and is separated from the contacting area 26 by the blocking area 24.

[0054] In the present embodiment, the contact area 26 is significantly longer than the fixing area 22, while the blocking area 24 is shorter than the fixing area 22. Although these proportions are determined by considerations regarding contact with the contact pad 14 and the card edge connector, the invention is not limited in this respect. Furthermore, it is not necessary for the fixing area 22 and the contact area 26 to each have substantially the same cross-section; for example, the contact area could also be wider in the transverse direction than the fixing area.

[0055] Between the contacting area 26 and the fixing area 22 is the blocking area 24, which has a reduction in cross-section, which in the present embodiment includes a waisting on the sides and a notch on the side of the contact element 20 facing away from the circuit board 10.

[0056] If the contact elements 20 are applied to the circuit board 10, for example by soldering (e.g. by applying solder paste between the contact pad 14 and the side of the fixing area 22 facing the circuit board 10 and applying heat accordingly for the actual soldering process), the contact elements 20 are located in a respective gap 16 in the coating 12. By appropriately dimensioning the gap 16 (particularly in its extent along the surface of the circuit board 10, but also with regard to the material thickness of the coating or the depth of the gap), it can advantageously be achieved that the contact elements 20 are aligned according to the gap 16.

[0057] Liquid solder present during soldering is prevented by the barrier area 24 from reaching the contact area 26, in particular its upper side facing away from the circuit board 10, which is intended for contact with the (not shown here) card edge connector.

[0058] The contact pads 14 are located in the area of ​​an edge of the circuit board 10, so that the contact elements 20 attached to them can be contacted by the card edge connector. It is not necessary for the contact elements 20 to extend all the way to the edge of the circuit board 10, as long as the respective contact areas 26 can be reached by the card edge connector.

[0059] The Fig. Figures 4 to 7 show schematic representations to illustrate a second embodiment of a circuit board according to the invention.

[0060] Fig. Figure 4 shows a second embodiment of the circuit board according to the invention with a card edge connector attached to it. Fig. Figure 5 shows the circuit board and the card edge connector. Fig. 5, which are separate from each other. Fig. 6 shows the ladder diagram from the Fig. 4 and Fig. 5 from a different perspective and Fig. Figure 7 shows the circuit board in an exploded view.

[0061] As already mentioned in the Fig. In the embodiment shown in Figures 1 to 3, the circuit board 110 of the present embodiment also has a slot 118 in which a rib 132 of the card edge connector 130 engages. Since those skilled in the art are familiar with the basic operating principle of card edge connectors, no further explanation is necessary in this respect.

[0062] In the present embodiment, the circuit board 110 essentially has block-shaped contact elements 120, i.e., designed as flat cuboids, which electrically contact (not shown here) contact pads of the circuit board 110, the contact pads in turn being connected to respective lines of the circuit board.

[0063] In Fig. 5. It is evident that they are also in Fig. The contact elements 120 shown are designed for contacting contacts 134 of the card edge connector 130. It should be noted that due to the perspective in Fig. 5 Only the lower sections of the contacts 134 of the card edge connector 130 are visible, while corresponding sections opposite these lower sections are provided for contacting the contact elements 120 shown on the top side of the circuit board 110. Corresponding contact elements are located on the underside of the circuit board 110 for the lower sections of the contacts 134. The contacts 134 of the card edge connector are in electrical contact with lines 136.

[0064] In Fig. Figure 7 shows that the contact elements 120, unlike in the first embodiment above, essentially correspond in their position and extent to the contact pads 114 of the circuit board 110, to which they are electrically connected, e.g. by soldering.

[0065] The Fig. Figures 8 to 11 show schematic representations to illustrate a first embodiment of a contact element arrangement according to the invention and a third embodiment of a printed circuit board according to the invention.

[0066] Fig. Figure 8 shows a third embodiment of the circuit board 210 according to the invention with a card edge connector 130 attached to it, which is equipped with an embodiment of a contact element arrangement. Fig. Figure 9 shows the circuit board and the card edge connector. Fig. 8, which are separated from each other. Fig. 10 shows the ladder map from the Fig. 8 and Fig. 9 from a different perspective and Fig. Figure 10 shows the circuit board and the contact element arrangements in an exploded view.

[0067] The representations of Fig. 8 to 11 largely correspond to those of Fig. 4 to 7. The card edge connector 130 in this example is identical to the card edge connector that is in Fig. 4 and Fig. 5 is shown.

[0068] Unlike the embodiment above, a contact element arrangement 240 is provided here instead of the individual contact elements 120. The contact element arrangement 240 comprises a receptacle 242 in which, in the present example (without this being intended to limit the invention), two contact elements 220 are received, such that, on the one hand, contacting areas 226 are exposed on the side facing away from the circuit board 210 in order to be able to make contact with contacts 134 of the card edge connector 130, and, on the other hand, the contact elements 220 are at least partially (in the present embodiment even completely) exposed on the side facing the circuit board 210 in order to make contact with contact pads (not shown here) of the circuit board 210.

[0069] The circuit board 210 also has a slot 218 corresponding to the bridge 132 of the card edge connector 130, and the contact element arrangement 240 and its receptacle 242 also have a corresponding slot. Since these slots correspond to each other, they can be considered positioning elements. However, projections located on the receptacle that engage in corresponding recesses in the circuit board can also be provided as positioning elements.

[0070] In Fig. Figure 11 shows the contact pads of the circuit board 210, which are not shown. These contact pads can be located along the length of the contact elements 220, with adjacent contact pads also being provided at different distances from the edge.

[0071] The Fig. 12 and Fig. Figure 13 shows schematic representations to illustrate the aspect of the present invention according to which printed circuit boards with different material thicknesses can be used with one and the same card edge connector if appropriate contact elements are provided.

[0072] Fig. Figure 12 shows a schematic representation of an embodiment of a “thin” printed circuit board with a card edge connector and Fig. Figure 13 shows a schematic representation of an embodiment of a “thick” printed circuit board with the card edge connector made of Fig. 12.

[0073] The terms "thick" and "thin" are not to be understood as absolute here, but merely indicate that the actual circuit board 310a, which is in Fig. As shown in Figure 12, the circuit board 310b itself has a lower material thickness. Fig. 13 is shown.

[0074] The circuit boards 310a and 310b each have contact elements 320a and 320b of different thicknesses, such that the total thickness (the sum of the material thickness) of the circuit board and the contact elements attached to it is the same within a permissible tolerance range, so that these circuit boards 310a, 320a, equipped with contact elements 320a, 320b, can be used with the same card edge connector 130 without requiring any further modifications.

[0075] It should be noted that the contact elements do not necessarily have to be provided on both sides. Furthermore, even if contact elements are provided on opposite sides of the circuit board, it is not necessary for the contact elements on both sides to have the same material thickness.

[0076] If only printed circuit boards (PCBs) with a specific number of board thicknesses need to be considered, the number of different contact elements can be reduced by using contact elements of varying thicknesses, compared to using contact elements with essentially the same thickness on both sides. For PCBs with board thicknesses of 1.6 mm, 1.8 mm, and 2.0 mm, three different contact element thicknesses would be required to achieve a common overall thickness, assuming identical board thicknesses. For a desired overall thickness of 2.2 mm, these would be contact elements with thicknesses of 0.1 mm, 0.2 mm, and 0.3 mm.For example, if only contact elements with material thicknesses of 0.1 mm and 0.3 mm are used, the circuit board with a material thickness of 1.8 mm can also be made 2.2 mm thick with contact elements of 0.1 mm material thickness on one side and 0.3 mm material thickness on the other side.

[0077] Fig. Figure 14 shows a schematic flowchart of an embodiment of the inventive method for providing a system with a printed circuit board according to the invention and a corresponding card edge connector.

[0078] In step S1, a circuit board is provided with a plurality of contact pads arranged in the area of ​​an edge of the circuit board, each of which is connected to one of a plurality of electrical lines of the circuit board.

[0079] In step S2, several plate-shaped contact elements are provided, for example according to one of the above embodiments.

[0080] The order of steps S1 and S2 is arbitrary and the steps can also be performed in parallel.

[0081] In step S3, the several plate-shaped contact elements are applied to a respective contact pad of the circuit board, so that the contact elements are designed to connect to the respective electrical contacts of the card edge connector.

[0082] In step S4, the order of which is arbitrary and can therefore be carried out in parallel to one or all of the steps S1 to S3, a card edge connector is provided.

[0083] Alternatively, in step S3, the multiple plate-shaped contact elements can be provided in such a way that they fit a given material thickness of the printed circuit board and a given dimension of the card edge connector. Alternatively, in step S4, the card edge connector can be selected with a dimension determined based on the material thickness of the printed circuit board and the material thickness of a contact element.

[0084] Even though the figures show various aspects or features of the invention in combination, it is apparent to those skilled in the art – unless otherwise stated – that the combinations shown and discussed are not the only possible ones. In particular, corresponding units or feature sets from different embodiments can be interchanged. This applies especially to the fact that the contact elements of the first embodiment can be provided instead of the contact elements of the second and third embodiments, or instead of the contact elements of the embodiment of the contact element arrangement. Reference symbol list 10, 110, 210, 320a, 320b ladder map 12 coating 14, 114 contact pad 16 gap 18, 118, 218 slots 20, 120, 220, 320a, 320b Contact element 22 Fixation area 24 Restricted area 26, 226 Contact area 130 card edge connectors 132 Bridge 134 Contact of a card edge connector 136 Management 240 contact element arrangement 242 recording S1 Provision of a circuit board S2 Provision of plate-shaped contact elements S3 Applying the contact elements S4 Provision of a card edge connector QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2013 110 082 A1 [0004, 0005, 0017] WO 2016 / 110279 A1 [0004, 0006, 0017]

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