Shielding arrangement
The invention relates to an enhanced shielding arrangement. A shielding arrangement comprises a shielding can and a layered printed circuit board having electrical components and at least two ground potential layers. There are grounding connections between edges of the shielding can and at least one of the ground potential layers, and grounding connections between components inside the shielding can and at least one of the ground potential layers, so that the two grounding connections are connected to each other only through at least one of the ground potential layers for providing small loops.
1. A shielding arrangement comprising:
a layered printed circuit board having at least one electrical component mounted on a first outer surface of the layered printed circuit board,
a shielding can mounted on the first outer surface of the layered printed circuit board, the shielding can covering said at least one electrical component,
a first ground potential layer being either inside the layered printed circuit board or on the first outer surface of the layered printed circuit board,
a second ground potential layer being either inside the layered printed circuit board or on a second outer surface of the layered printed circuit board and being farther from the first outer surface of the layered printed circuit board than the first ground potential layer,
at least one grounding connection between the edges of the shielding can and the first ground potential layer,
at least one grounding connection from the first ground potential layer or the shielding can to the second ground potential layer, the shielding can, the first ground potential layer, the second ground potential layer, and the grounding connection thus forming a Faraday cage,
a third ground potential layer being inside the layered printed circuit board between the first ground potential layer and the second ground potential layer, and
at least one grounding connection between the electrical components inside the shielding can and the third ground potential layer.
2. A shielding arrangement according to claim 1 , wherein the grounding connections of the shielding can and the grounding connections of the components inside the shielding can are isolated in uppermost signal layers of the multilayered printed circuit board.
3. A shielding arrangement according to claim 1 , comprising a coaxial shielding paths between ground potential layers for signals emerging inside the shielding can.
4. A shielding arrangement according to claim 1 , wherein signals emerge from between the ground potential layers to said electrical component only within coverage of the shielding can.
5. A shielding arrangement according to claim 1 , comprising a coaxial shielding paths between ground potential layers of the printed circuit board for a whole coupling path from a source emitting signals to a receptive component.
6. A shielding arrangement according to claim 1 , wherein the shielding arrangement comprises at least one signal layer being inside the layered circuit board between the third ground potential layer and the first ground potential layer.