Shielding for EMI-sensitive electronic components and or circuits of electronic devices
View Patent ↗A shielding apparatus for EMI-sensitive electronic components, especially for radio transmitting devices and/or radio receiving devices of telecommunication terminals for contactless telecommunication, such as cordless telephones and mobile telephones and similar, which can be constructed without using expensive manufacturing and assembly steps without any extra space requirement. The EMI-sensitive electronic components and/or circuits are arranged on a separate, at least double-layered printed circuit board and are embodied as a printed circuit board module. Said circuit board and another separate, at least two-layered circuit board which includes a recess for the EMI-sensitive electronic components and/or circuits and which is embodied in the form of a base printed circuit board, are joined together by soldering, preferably in the region of contact areas, to form a unit such that a cage is formed by the recess which is disposed between two metal surfaces being respectively connected to the shielding surfaces by means of continuous, highly adjacent contacts. The cage shields the EMI-sensitive electronic components and/or circuits on all sides.
1. A shielding apparatus for EMI-sensitive components, comprising:
a first circuit board, having a plurality of layers having interfacial connections, said first circuit board including a first base surface and a recess opening on one layer in which non-EMI-sensitive components are arranged;
a first contact area encompassing the recess opening;
a first earth face, which corresponds to an area of the base surface and the recess opening, wherein the non-EMI-sensitive components are arranged outside the first contact area or the first earth face;
a second circuit board, having a plurality of layers having interfacial connections, said second board including a second base surface on one layer in which EMI-sensitive components are arranged;
a second contact area encompassing the EMI-sensitive components; and
a second earth face, corresponding to an area of the second base surface,
wherein the first and second circuit board are coupled via joining means, and wherein said EMI-sensitive components are arranged within the recess opening of the first printed circuit board, and wherein at least some of the interfacial connections, together with the recess and the first and second earth faces, form a cage in which the EMI-sensitive components are shielded.
2. The shielding apparatus of claim 1 , wherein the first earth face is disposed between the recess opening of the first base surface and a side of the circuit board facing away from the recess opening.
3. The shielding apparatus of claim 1 , wherein the first earth face is disposed in a plane of the first base surface.
4. The shielding apparatus of claim 1 , wherein the first earth face is disposed in a plane of a side of the circuit board facing away from the recess opening.
5. The shielding apparatus of claim 1 , wherein the second earth face is disposed between the EMI-sensitive component circuit board layer and a side facing away from the EMI-sensitive component circuit board layer.
6. The shielding apparatus of claim 1 , wherein the second earth face is disposed in a plane of a side facing away from the EMI-sensitive component circuit board layer.
7. The shielding apparatus of claim 1 , wherein the interfacial connections are spaced apart by a distance less than one-tenth of the wavelength (λ) of an electromagnetic radiation emitted by the components.
8. The shielding apparatus of claim 1 , wherein the interfacial connections pass through their respective earth faces.
9. The shielding apparatus of claim 1 , wherein the interfacial connections are filled with a filling material.
10. The shielding apparatus of claim 9 , wherein the filling material is resin-based.
11. The shielding apparatus of claim 1 , wherein the interfacial connections are connected to each respective earth face and to a respective contact area.
12. The shielding apparatus of claim 11 , further comprising two gaps between the second contact area and a respective interfacial connection having first signal lines, wherein said signal lines transmit signals to and from the EMI-sensitive components on the second circuit board.
13. The shielding apparatus of claim 12 , further comprising two gaps between the first contact area and a respective interfacial connection having second signal lines, wherein said second signal lines are coupled to the first signal lines outside the recess opening.
14. The shielding apparatus of claim 1 , wherein the earth faces are configured as continuous faces.
15. The shielding apparatus of claim 1 , wherein the earth faces are configured as grid faces, with grid line spacing of less than one-tenth of the wavelength (λ) of an electromagnetic radiation emitted by the components.
16. The shielding apparatus of claim 1 , wherein the non-EMI-sensitive components are surface mounted devices.
17. The shielding apparatus of claim 1 , wherein the first contact area includes a first shielding face through which first interfacial connections pass, and a second shielding face through which second interfacial connections pass.