Surface-mountable over-current protection device

Patent metadata

Field	Value
Publication number	US-10096407-B2
Application number	US-201715437975-A
Country	US
Kind code	B2
Filing date	Feb 21, 2017
Priority date	Jul 29, 2016
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

A surface mountable over-current protection device comprises a PTC material layer, first and second conductive layers, left and right electrodes, left and right conductive members, and left and right insulating members. The PTC material layer comprises a left notch at a left end and a right notch at a right end. The first conductive layer comprises a primary portion disposed on an upper surface of the PTC material layer and a secondary portion extending over the left notch, and the second conductive layer comprises a primary portion disposed on a lower surface of the PTC material layer and a secondary portion extending over the underside of the right notch. The left conductive member connects to the left electrode and the first conductive layer and isolates from the second conductive layer. The right conductive member connects to the right electrode and the second conductive layer and isolates from the first conductive layer. The left and right insulating members are disposed in the left and right notches, respectively. The PTC material layer is not in direct contact with the left and right conductive members, and the primary portion and the secondary portion of the first or second conductive layer have different thicknesses.

First claim

What is claimed is:

1. A surface-mountable over-current protection device, comprising:
a PTC material layer having opposite left and right ends, the left end comprising a left notch, the right end comprising a right notch;
a first conductive layer comprising a primary portion disposed on an upper surface of the PTC material layer and a secondary portion extending over the left notch;
a second conductive layer comprising a primary portion disposed on a lower surface of the PTC material layer and a secondary portion extending over the underside of the right notch;
a left electrode electrically connecting to the first conductive layer;
a right electrode electrically connecting to the second conductive layer;
a left conductive member connecting to the left electrode and the first conductive layer and isolating from the second conductive layer;
a right conductive member connecting to the right electrode and the second conductive layer and isolates from the first conductive layer;
a left insulating member disposed in the left notch and between the left conductive member and the PTC material layer for isolation; and
a right insulating member disposed in the right notch and between the right conductive member and the PTC material layer for isolation;
wherein the PTC material layer is not in direct contact with the left and right conductive members, and the primary portion and the secondary portion of the first conductive layer or the second conductive layer have difference thicknesses.

2. The surface-mountable over-current protection device of claim 1 , wherein the primary portion is thicker than the secondary portion.

3. The surface-mountable over-current protection device of claim 1 , wherein the primary portion is a laminate comprising a first metal layer and a second metal layer, and the secondary portion comprises the second metal layer.

4. The surface-mountable over-current protection device of claim 3 , wherein the second metal layer is an electroplated layer on the first metal layer.

5. The surface-mountable over-current protection device of claim 1 , wherein the left insulating member and the right insulating member are in the shape of a half cylinder, and the ratio of height to radius of the half cylinder is 1-15.

6. The surface-mountable over-current protection device of claim 1 , wherein the first conductive layer has a right end with a notch aligned with the right notch, and the second conductive layer has a left end with a notch aligned with the left notch.

7. The surface-mountable over-current protection device of claim 1 , wherein the left notch and right notch are in semi-circular or semi-ellipse shapes, and the left conductive member and the right conductive member are semi-circular or semi-ellipse conductive through holes.

8. The surface-mountable over-current protection device of claim 1 , further comprising:
a first insulating layer disposed on an upper surface of the first conductive layer from the left conductive member to the right conductive member; and
a second insulating layer disposed on a lower surface of the second conductive layer from the left conductive member to the right conductive member.

9. The surface-mountable over-current protection device of claim 8 , wherein the left electrode or the right electrode comprises two electrode sections disposed on an upper surface of the first insulating layer and a lower surface of the second insulating layer.

10. The surface-mountable over-current protection device of claim 8 , wherein the first insulating layer and the second insulating layer comprise prepreg.

11. The surface-mountable over-current protection device of claim 8 , wherein a material of the first insulating layer and the second insulating layer differ from that of the left insulating member and the right insulating member.

12. The surface-mountable over-current protection device of claim 8 , wherein CTE in vertical direction of the left and right insulating members is smaller than CTE in vertical direction of the first and second insulating layers.

13. The surface-mountable over-current protection device of claim 1 , wherein the left insulating member and the right insulating member comprise insulating resin without fiberglass.

14. The surface-mountable over-current protection device of claim 13 , wherein CTE of the insulating resin at a temperature below Tg is less than 50 ppm.

15. The surface-mountable over-current protection device of claim 13 , wherein the insulating resin has a viscosity of 30-60 Pa·s at 25° C.

16. The surface-mountable over-current protection device of claim 1 , wherein the left and right insulating members comprise insulating resin with fillers selected from the group consisting of SiO 2 , TiO 2 , Al 2 O 3 , Al(OH) 3 and Mg(OH) 2 .

Assignees

• Polytronics Technology Corp

Inventors

• Tseng Chun Teng
• Lee Wen Feng
• Chang Yung Hsien
• Chang Yao Te

Classifications

• H01C7/13 Primary

  current-responsive · CPC title

• H01C7/021 Primary

  formed with two or more layers · CPC title

• H01C1/1406

  Terminals or electrodes formed on resistive elements having positive temperature coefficient · CPC title