1. Field of the Invention
The invention relates to a fastening element, a connection system, and a method for connecting a housing to a printed circuit board.
2. Related Art
In many electronic devices, a printed circuit board has to be connected to or housed in a housing. Additionally, if the device is sensitive to electromagnetic radiation or emits electromagnetic radiation, for example, in car radio devices, shieldings have to be attached to the PCB and/or the housing. Releasable connections, for example screwed connections, are preferred, as this simplifies maintenance and repair actions. Several connection methods for connecting a housing, a printed circuit board, and optionally a shielding are known in the art, but they all suffer from various disadvantages.
For example, soldering the shielding to the printed circuit board and connecting the shielding to the housing has certain disadvantages. First, when connecting the shielding with a self-tapping screw through a hole in the housing and a thread cut by the screw in the shielding, as the shielding plates are normally rather thin, there is a great risk of overwinding the screw due to the low mechanical strength of the thin shielding plate. As an alternative an insert nut can be inserted into the shielding, but this increases the cost of production and complicates the production process. Furthermore, the connection of the printed circuit board to the housing via the shielding is not very reliable, as the shielding might tear due to mechanical loads and vibrations.
Connecting the printed circuit board to the housing via a screw extending through a hole in the printed circuit board into a thread of the housing is only possible if the printed circuit board and the surface of the housing to which the printed circuit board has to be connected to, are in parallel. If the printed circuit board and the surface of the housing are perpendicular in the area where they have to be connected, a threaded protrusion has to be provided at the housing, which increases production costs and makes the production process of the housing more complicated. Furthermore, a separate connection has to be provided for an optional shielding. Moreover, it is common for the above-mentioned connecting methods to be difficult to implement in automated production process.
Therefore, a need exists for providing a fastening element for connecting a housing to a printed circuit board that provides a releasable and reliable connection between a printed circuit board and a housing that is capable of optionally including the connection to a shielding, and which is capable of being processed automatically by a mounting tool or a robot.