Surface mount multilayer coupling capacitor and circuit board containing the same
The present invention is directed to a surface mount coupling capacitor and a circuit board containing a surface mount coupling capacitor. The coupling capacitor includes a main body containing at least two sets of alternating dielectric layers and internal electrode layers. The coupling capacitor includes external terminals electrically connected to the internal electrode layers wherein the external terminals are formed on a top surface of the coupling capacitor and a bottom surface of the coupling capacitor opposing the top surface of the coupling capacitor.
1. A surface mount multilayer coupling capacitor comprising:
a main body containing a first set of alternating dielectric layers and internal electrode layers and a second set of alternating dielectric layers and internal electrode layers,
each set of alternating dielectric layers and internal electrode layers containing a first internal electrode layer and a second internal electrode layer wherein the first set is spaced apart from the second set in a longitudinal direction and wherein a major surface of the internal electrode layers is in a longitudinal direction,
each internal electrode layer including a top edge, a bottom edge opposite the top edge, and two side edges extending between the top edge and the bottom edge that define a main body of the internal electrode layer,
external terminals electrically connected to the internal electrode layers wherein the external terminals are formed only on a top surface of the coupling capacitor and a bottom surface of the coupling capacitor opposing the top surface of the coupling capacitor, wherein the first internal electrode layers of the first set and the second set connect to the external terminals on the top surface and the second electrode layers of the first set and the second set connect to the external terminals on the bottom surface.
2. The multilayer coupling capacitor according to claim 1 , wherein the capacitor provides an impedance differential of 100 Ω±10%.
3. The multilayer coupling capacitor according to claim 1 , wherein the capacitor exhibits an insertion loss of 0.25 dB or less.
4. The multilayer coupling capacitor according to claim 1 , wherein at least one of the first internal electrode layer or the second internal electrode layer electrically contacts the external terminal on the top surface of the coupling capacitor and the other internal electrode layer electrically contacts the external terminal on the bottom surface of the coupling capacitor opposing the top surface of the coupling capacitor.
5. The multilayer coupling capacitor according to claim 1 , wherein at least one lateral edge of the first internal electrode layer is substantially aligned with at least one lateral edge of the second internal electrode layer.
6. The multilayer coupling capacitor according to claim 1 , wherein both lateral edges of the first internal electrode layer are substantially aligned with both lateral edges of the second internal electrode layer.
7. The multilayer coupling capacitor according to claim 1 , wherein the dielectric layers comprise a ceramic.
8. The multilayer coupling capacitor according to claim 7 , wherein the ceramic comprises a titanate.
9. The multilayer coupling capacitor according to claim 1 , wherein the internal electrode layers comprise a conductive metal.
10. The multilayer coupling capacitor according to claim 9 , wherein the conductive metal comprises nickel or an alloy thereof.
11. The multilayer coupling capacitor according to claim 1 , wherein the external terminals are electroplated layers.
12. The multilayer coupling capacitor according to claim 1 , wherein the external terminals are electroless plated layers.
13. The multilayer coupling capacitor according to claim 1 , wherein the external terminals comprise a conductive metal.
14. The multilayer coupling capacitor according to claim 13 , wherein the conductive metal comprises silver, gold, palladium, platinum, tin, nickel, chrome, titanium, tungsten, or combinations or alloys thereof.
15. The multilayer coupling capacitor according to claim 13 , wherein the conductive metal comprises copper or an alloy thereof.
16. The multilayer coupling capacitor according to claim 1 , wherein a pitch of the external terminals is from about 0.1 mm to about 2 mm.
17. A circuit board containing the coupling capacitor of claim 1 .
18. A communications device containing the coupling capacitor of claim 1 .
19. The communications device of claim 18 , wherein the communications device includes an Ethernet system, a wireless network router, a fiber optic communications system, or a storage device.
20. A surface mount multilayer coupling capacitor comprising:
a main body containing a first set of alternating dielectric layers and internal electrode layers and a second set of alternating dielectric layers and internal electrode layers,
each set of alternating dielectric layers and internal electrode layers containing a first internal electrode layer and a second internal electrode layer wherein the first set is spaced apart from the second set in a longitudinal direction and wherein a major surface of the internal electrode layers is in a longitudinal direction,
each internal electrode layer including a top edge, a bottom edge opposite the top edge, and two side edges extending between the top edge and the bottom edge that define a main body of the internal electrode layer,
external terminals electrically connected to the internal electrode layers wherein the external terminals are formed on a top surface of the coupling capacitor and a bottom surface of the coupling capacitor opposing the top surface of the coupling capacitor, wherein the first internal electrode layers of the first set and the second set connect to the external terminals on the top surface and the second electrode layers of the first set and the second set connect to the external terminals on the bottom surface.