Dielectric component array with failsafe link
View Patent ↗The invention includes an electromagnetic filter for a feedthrough conductor, and a method of making such a filter. At least two dielectric components are supported from a first side of a substrate, such as a housing or a printed circuit board. At least one of the dielectric components is associated with a failsafe link.
1. An electromagnetic filter comprising:
a substrate having a substantially planar first side, a second side and a feedthrough surface, the feedthrough surface defining an orifice extending from the first side to the second side;
a feedthrough conductor extending through the orifice;
a first dielectric component supported from the first side and partially surrounding the conductor;
a second dielectric component supported from the first side and partially surrounding the conductor;
a noise handling circuit terminal on the substrate; and
a failsafe link electrically connecting at least one of the dielectric components to the noise handling circuit terminal.
2. The filter of claim 1 , wherein the first dielectric component is a capacitor.
3. The filter of claim 1 , wherein the failsafe link includes a trace fixed to the first side of the substrate.
4. The filter of claim 1 , wherein the first dielectric component has a first conductive plate electrically connected to and at the same electric potential as the failsafe link, and a second conductive plate separated from the first conductive plate by a dielectric material.
5. The filter of claim 1 , wherein the failsafe link is at a first electric potential and the conductor is at a second electric potential.
6. The filter of claim 1 , wherein the first dielectric component is joined to the substrate by a conductive material.
7. The filter of claim 1 , further comprising a via electrically connecting the noise handling circuit terminal to the failsafe link.
8. The filter of claim 1 , wherein the failsafe link includes a first conductive precursor and a second conductive precursor electrically joined by a fusible bridge.
9. The filter of claim 8 , wherein the fusible bridge is formed from a first material and the first conductive precursor is formed from a second material.
10. The filter of claim 1 , wherein the failsafe link includes a first conductive precursor and a second conductive precursor electrically joined by a dielectric bridge.
11. The filter of claim 1 , wherein the failsafe link is a dielectric link or a fusible link.
12. A method of providing an electromagnetic filter, comprising:
providing a substrate having a substantially planar first side, a second side and a feedthrough surface, the feedthrough surface defining an orifice extending from the first side to the second side;
providing a feedthrough conductor extending through the orifice;
supporting a first dielectric component from the first side and proximate to the feedthrough conductor;
supporting a second dielectric component from the first side and proximate to the feedthrough conductor;
providing a noise handling circuit terminal on the substrate; and
providing a failsafe link electrically connecting at least one of the dielectric components to the noise handling circuit terminal.
13. The method of claim 12 , wherein the failsafe link is provided by:
providing a first conductive precursor and a second conductive precursor having a gap between the precursors;
providing a fusible bridge between the precursors.