Common mode filter
Disclosed herein is a common mode filter. The common mode filter includes a main body that includes a coil electrode, first and second external electrodes connected with both ends of the coil electrode, respectively, and a ground electrode, and an electro static discharge (ESD) protection layer that includes a switching member formed therein, and is provided on any one surface of the main body. Here, one end of the coil electrode is connected with the second external electrode, the other end thereof is connected with the first external electrode through the switching member, and the switching member is disconnected from the coil electrode in accordance with a switching operation when a surge current is applied and connected with the ground electrode. Therefore, it is possible to protect the common mode filter from a surge current by ESD.
1. A common mode filter comprising:
a main body that includes a coil electrode, first and second external electrodes connected with both ends of the coil electrode, respectively, and a ground electrode; and
an ESD protection layer that includes a switching member formed therein, and is provided on any one surface of the main body,
wherein one end of the coil electrode is connected with the second external electrode, the other end thereof is connected with the first external electrode through the switching member, and the switching member is disconnected from the coil electrode in accordance with a switching operation when a surge current is applied and connected with the ground electrode.
2. The common mode filter according to claim 1 , wherein the ESD protection layer includes a permanent magnetic body that forms a magnetic field around the switching member.
3. The common mode filter according to claim 2 , wherein the permanent magnetic body is disposed so as to be parallel to the switching member.
4. The common mode filter according to claim 1 , wherein the switching member is provided so as to be fixed on a support portion protruding to an empty space inside the ESD protection layer.
5. The common mode filter according to claim 4 , wherein the support portion is provided on each of both ends of the switching member, and the both ends of the switching member are provided so as to be fixed on the support portion, respectively.
6. The common mode filter according to claim 1 , wherein the switching member includes:
a conductive magnetic film in which distortion occurs when the surge current is applied,
a signal line that connects both ends of the conductive magnetic film, and
a polymer elastic body that wraps the conductive magnetic film and the signal line.
7. The common mode filter according to claim 6 , wherein the switching member further includes
a protrusion terminal that is formed on upper and lower portions of the polymer elastic body, and passes through the polymer elastic body so as to be connected with the signal line.
8. A common mode filter comprising:
a main body that includes a coil electrode, first and second external electrodes connected with both ends of the coil electrode, and a ground electrode; and
an ESD protection layer that includes a switching member formed therein and is provided on any one surface of the main body,
wherein the first external electrode is connected with the switching member through a first lead wire extending from the first external electrode, one end of the coil electrode is connected with the second external electrode through a via, the other end thereof is connected with the switching member through a second lead wire extending from the other end thereof, and the switching member is disconnected from the second lead wire in accordance with a switching operation when a surge current is applied and connected with the ground electrode through a third lead wire extending from the ground electrode.
9. The common mode filter according to claim 8 , wherein the ESD protection layer includes a permanent magnetic body that forms a magnetic field around the switching member.
10. The common mode filter according to claim 9 , wherein the permanent magnetic body is disposed so as to be parallel to the switching member.
11. The common mode filter according to claim 8 , wherein the first to third lead wires are buried in an inner wall of the ESD protection layer.
12. The common mode filter according to claim 8 , wherein the switching member is provided so as to be fixed on a support portion protruding to an empty space inside the ESD protection layer.
13. The common mode filter according to claim 12 , wherein the support portion is provided on each of both ends of the switching member, and the both ends of the switching member are provided so as to be fixed on the support portion, respectively.
14. The common mode filter according to claim 13 , wherein an end of the first lead wire is buried in any one of the support portions that fix the both ends of the switching member to thereby be connected with the switching member.
15. The common mode filter according to claim 8 , wherein the switching member includes:
a conductive magnetic film in which distortion occurs when the surge current is applied,
a signal line that connects both ends of the conductive magnetic film, and
a polymer elastic body that wraps the conductive magnetic film and the signal line.
16. The common mode filter according to claim 15 , wherein the switching member further includes a protrusion terminal that is formed on upper and lower portions of the polymer elastic body, and passes through the polymer elastic body so as to be connected with the signal line.
17. The common mode filter according to claim 15 , wherein an end of the first lead wire is connected with the signal line.
18. The common mode filter according to claim 8 , wherein an end of the second lead wire is constituted of a terminal that protrudes to an empty space inside the ESD protection layer.
19. The common mode filter according to claim 8 , wherein an end of the third lead wire is constituted of a terminal that protrudes to an empty space inside the ESD protection layer.
20. The common mode filter according to claim 8 , wherein the main body includes an insulating layer that buries the coil electrode, the first and second external electrodes and the ground electrode formed on the insulating layer, and a magnetic composite that is formed between the first and second external electrodes and the ground electrode.
21. The common mode filter according to claim 8 , wherein the main body and the ESD protection layer, or the ESD protection layer and the main body are sequentially provided on a magnetic body substrate.