Circuit protection device
A circuit protection device including a PTC device and a diode. A first insulation layer is formed between first electrode surfaces of the diode and the PTC device. Vias for thermally and electrically connecting the first electrode surfaces of the diode and the PTC device are formed in the first insulation layer. First, second, and third external electrode pads are provided on a second insulation layer formed on the second electrode surface of the PTC device. The second electrode surface of the PTC device is electrically connected to the first external electrode pad. The first electrode surface of the diode and the first electrode surface of the PTC device are electrically connected to the second external electrode pad. A second electrode surface of the diode is electrically connected to the third external electrode pad.
1. A circuit protection device, comprising:
a PTC device having a first electrode surface and a second electrode surface opposite to the first electrode surface of the PTC device;
a diode having a first electrode surface and a second electrode surface opposite to the first electrode surface of the diode;
a first insulation layer disposed between the first electrode surface of the diode and the first electrode surface of the PTC device;
vias extending through the first insulation layer thermally and electrically connecting the first electrode surface of the diode and the first electrode surface of the PTC device;
a second insulation layer on the second electrode surface of the PTC device;
a first external electrode pad on the second insulation layer electrically connected to the second electrode surface of the PTC device by a first conductive through hole extending through the second insulation layer;
a second external electrode pad on the second insulation layer electrically connected to the first electrode surface of the diode and the first electrode surface of the PTC device by a second conductive through hole extending through the second insulation layer; and
a third external electrode pad on the second insulation layer electrically connected to the second electrode surface of the diode;
wherein the first, second, and third external electrode pads are entirely disposed on a side of the second insulation layer opposite the PTC device.
2. The circuit protection device according to claim 1 , wherein the PTC device has a plate shape and the diode has a sheet shape and overlays the PTC device.
3. The circuit protection device according to claim 1 , further comprising an electric connector having a first end electrically connected to the second electrode surface of the diode and a second end electrically connected to the third external electrode pad by a third conductive through hole.
4. The circuit protection device according to claim 3 , wherein the electric connector has a sheet-shaped electric connection board form, and comprises:
(a) a first portion extending parallel with the second electrode surface of the diode and electrically connected to the second electrode surface of the diode; and
(b) a second portion perpendicular to the first portion and electrically connected to the third external electrode pad through the third conductive through hole.
5. The circuit protection device according to claim 4 , further comprising an outer insulation protection layer covering the diode and the electric connector.
6. The circuit protection device according to claim 5 , wherein the first electrode surface of the diode is a negative electrode surface and the second electrode surface of the diode is a positive electrode surface.
7. The circuit protection device according to claim 6 , wherein:
(a) the first external electrode pad electrically connected to the second electrode surface of the PTC device serves as a voltage or current input end;
(b) the second external electrode pad electrically connected to the first electrode surface of the PTC device and the first electrode surface of the diode serves as a voltage or current output end; and
(c) the third external electrode pad electrically connected to the second electrode surface of the diode serves as a ground connection end.
8. The circuit protection device according to claim 7 , wherein the surfaces of the first external electrode pad, the second external electrode pad, and the third external electrode pad are in the same plane.