PRINTED CIRCUIT BOARD WITH A CONTACT POINT

20230105384 ยท 2023-04-06

    Inventors

    Cpc classification

    International classification

    Abstract

    A printed circuit board, including: a contact point for contacting; a contact spring for an electrical contact in a vehicle; in which the contact point has a support element of tin that is reflow soldered to the printed circuit board. Also described are a related module and method.

    Claims

    1-10. (canceled)

    11. A printed circuit board, comprising: a contact point for contacting; a contact spring for an electrical contact in a vehicle; wherein the contact point has a support element of tin that is reflow soldered to the printed circuit board.

    12. The printed circuit board of claim 11, wherein the support element is above the printed circuit board, and has a height of at least 50 micrometers and at most 150 micrometers so as to ensure vibration-resistant contacting.

    13. The printed circuit board of claim 11, wherein the support element has one of the following footprints: a circular disk, an oval disk, a circular ring, or a face with a polygonal periphery, and wherein of the one of the footprints, further clearances are present in the interior thereof.

    14. A module for a vehicle or a commercial vehicle, comprising: a printed circuit board, including: a contact point for contacting; a contact spring for an electrical contact in a vehicle; wherein the contact point has a support element of tin that is reflow soldered to the printed circuit board; and a construction element, which is electrically connected by the contact spring to the support element of the contact point of the printed circuit board.

    15. The module of claim 14, wherein the contact spring bears on the support element by way of one end, and wherein a surface of the support element is larger than a cross-sectional area of the bearing end of the contact spring.

    16. The module of claim 15, wherein the surface of the support element has a depression and/or a bulge for receiving the bearing end of the contact spring, so as to secure a position of the bearing end of the contact spring.

    17. The module of claim 14, wherein the construction element has an actuator and/or a sensor for establishing an electrical connection between the actuator and/or the sensor and the printed circuit board in the vehicle, which is a commercial vehicle.

    18. A method for producing a printed circuit board with a contact point, the method comprising: providing a printed circuit board with a contact pad; applying a support element of tin to the contact pad; connecting the support element to the printed circuit board by reflow soldering.

    19. The method of claim 18, wherein the applying of the support element includes printing the contact pad with a solder paste, and wherein solder fluxes present by heating are consumed to the extent that the solder fluxes, when contacting a conductor bearing on the contact point, do not reduce the conductivity of the contact point.

    20. The method of claim 18, wherein at least one surface mounted construction element is to be fastened to the printed circuit board, and wherein the connecting includes simultaneous soldering of the support element and of the surface mounted construction element.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0047] FIG. 1 shows an exemplary embodiment according to the present invention of a printed circuit board with a contact point.

    [0048] FIG. 2 on the left shows a support element and on the right shows a plan view of a printed circuit board with a contact pad.

    [0049] FIG. 3 on the left shows a support element placed on a contact pad with solder paste, prior to heating and fusing in a reflow method, and on the right shows the support element on the contact pad after heating and fusing.

    [0050] FIG. 4 shows a module having a printed circuit board with a support element, a spring and a component.

    [0051] FIG. 5 shows a method for producing a printed circuit board with a contact point according to the present invention.

    DETAILED DESCRIPTION

    [0052] FIG. 1 shows an exemplary embodiment of the present invention of a printed circuit board 100 having a contact point for contacting, having a contact spring 300 for an electrical contact in a vehicle, wherein the contact point has a support element 200 of tin which by a reflow method is soldered to the printed circuit board 100.

    [0053] Illustrated here is a portion of the printed circuit board 100, the latter potentially containing further components. The contact spring 300 is not fixed to the support element 200 but needs only to bear thereon.

    [0054] FIG. 2 on the left-hand side shows a view of an exemplary embodiment of the support element 200 as a solder preform produced from tin. Illustrated on the right-hand side is a fragment of an exemplary embodiment of a printed circuit board 100 in a plan view, a contact pad 110 being situated in the latter. The contact pad 110 is a region of the printed circuit board 100 in which a conductor path of the printed circuit board 100 (not illustrated here) appears on the printed circuit board surface. Such conductor paths can consist, for example, of copper. Since oxidation processes compromise the contactability of exposed copper over time, the contact pad 110 in one of the last method steps for producing the printed circuit board 100 is coated with a surface finish, for example of tin, silver or gold.

    [0055] FIG. 3 on the left-hand side shows a local cross section through a printed circuit board 100 in a situation prior to solder being remelted in a reflow method. A contact pad 110 having solder paste 210 applied thereto is situated on the printed circuit board 100, a solder preform of tin as the support element 200 in turn bearing on said contact pad 110. The tin of the support element 200 in the reflow method fuses with the solder paste 210 and optionally, for example when configuring the surface finish of the contact pad 110 of tin, with the material of the surface finish of the contact pad 110.

    [0056] Illustrated on the right-hand side of the figure is the printed circuit board 100 with the contact pad 110 and the support element 200 after remelting of solder in the reflow method. A contact point that adjoins the conductor path in a homogenous manner can in particular be formed in this way in the case of a contact pad 110 with a surface finish of tin.

    [0057] FIG. 4 shows a lateral sectional view of an exemplary embodiment of a module for a vehicle, in particular a commercial vehicle, having a printed circuit board 100 in which a contact pad 110 is configured, a support element 200 of tin being attached to said contact pad 110 in the context of a reflow method. A contact spring 300 bears on the support element 200, said contact spring 300 being part of a construction element 400 which by way of the contact spring 300 is electrically connected to the support element 200 of the contact point of the printed circuit board 100.

    [0058] The printed circuit board 100 can be part of a sensor in a brake system of a vehicle, for example.

    [0059] A surface finish of the contact pad 110 of tin, prior to the support element 200 being applied, can have a thickness of one micrometer, for example. This thickness is typically reduced during the reflow method, for example by 0.2 micrometers. This thickness would be insufficient for a contact spring 300 to bear thereon, because corrosion and oxidation processes, and, when the contact spring 300 bears thereon, also abrasion processes, rapidly corrupt the surface finish. The support element 200 above the printed circuit board 100 can advantageously have a height in a range from 50 to 150 micrometers, and as a result ensure long-term contacting as well as the protection of a conductor path of the printed circuit board 100 that terminates at the contact pad 110. Since the height may be partially reduced during the reflow method, the support element 200 prior to being placed on the contact pad 110 of the printed circuit board 100 has a greater height (for example by 10 to 50 micrometers).

    [0060] The construction element 400 can comprise, for example, an actuator such as, for instance, a solenoid valve, in a brake system of a vehicle.

    [0061] FIG. 5 shows a method for producing a printed circuit board 100 with a contact point, said method comprising the following steps: [0062] providing S110 a printed circuit board 100 with a contact pad 110; [0063] applying S120 a support element 200 of tin to the contact pad 110; [0064] connecting S130 the support element 200 to the printed circuit board 100 by a reflow method.

    [0065] The support element 200 during the reflow method is liquefied by heating, wherein said support element 200 can fuse with a previously applied solder paste 210 and optionally with the material of a surface finish of the contact point 110. A homogenous contact with a conductor path of the printed circuit board 100 that terminates in the contact pad 110 is established as a result.

    [0066] The reflow method here can comprise assembling further components on the printed circuit board 100. In this way, the attaching of the contact point can be integrated in an existing reflow method, without the requirement of introducing an additional method step.

    [0067] The features of the invention that are disclosed in the description, the claims and the figures can be essential for implementing the invention individually as well as in any arbitrary combination.

    THE LIST OF REFERENCE SIGNS IS AS FOLLOWS

    [0068] 100 Printed circuit board [0069] 110 Contact pad [0070] 200 Support element [0071] 210 Solder paste [0072] 300 Contact spring [0073] 400 Construction element [0074] S110, S120, S130 Method steps