Connection arrangement with 1.1 a plug element which comprises 1.2 at least one pluggable spring-like contact element, in particular a plurality of pluggable spring-like contact elements with a reversible deflection characteristic, and with 1.3 a circuit board with plated-through bores, 1.4 which are arranged in an arrangement which corresponds to the arrangement of the contact element or the contact elements of the plug element, wherein 1.5 the bores and the contact element which is pluggable in them or the contact elements which are pluggable in them are adapted to each other, such that 1.6 the plug element can be connected with the circuit board by hand by plugging the contact element or the contact elements into the bores, and can be removed by hand; 1.7 and with a vibration-robust mechanical security against unintentionally detaching the plug element from the circuit board; wherein the contact element and the vibration-robust mechanical security are provided separately from each other, wherein the contact element or the contact elements comprises or comprise two legs which leave an intermediate space between each other; wherein the contact element or the contact elements is or are provided as two curved spring elements with a distance to each other, wherein the intermediate space is present within one of the bores at least in the region in which the respective contact elements, after plugging-in, are arranged, wherein the ends of the legs comprise the intermediate space between each other. 1.1 a plug element which comprises 1.2 at least one pluggable spring-like contact element, in particular a plurality of pluggable spring-like contact elements with a reversible deflection characteristic, and with 1.3 a circuit board with plated-through bores, 1.4 which are arranged in an arrangement which corresponds to the arrangement of the contact element or the contact elements of the plug element, wherein 1.5 the bores and the contact element which is pluggable in them or the contact elements which are pluggable in them are adapted to each other, such that 1.6 the plug element can be connected with the circuit board by hand by plugging the contact element or the contact elements into the bores, and can be removed by hand; 1.7 and with a vibration-robust mechanical security against unintentionally detaching the plug element from the circuit board; wherein the contact element and the vibration-robust mechanical security are provided separately from each other, wherein the contact element or the contact elements comprises or comprise two legs which leave an intermediate space between each other; wherein the contact element or the contact elements is or are provided as two curved spring elements with a distance to each other, wherein the intermediate space is present within one of the bores at least in the region in which the respective contact elements, after plugging-in, are arranged, wherein the ends of the legs comprise the intermediate space between each other. wherein the contact element and the vibration-robust mechanical security are provided separately from each other, wherein the contact element or the contact elements comprises or comprise two legs which leave an intermediate space between each other; wherein the contact element or the contact elements is or are provided as two curved spring elements with a distance to each other, wherein the intermediate space is present within one of the bores at least in the region in which the respective contact elements, after plugging-in, are arranged, wherein the ends of the legs comprise the intermediate space between each other.