US 12,288,980 B2
Over-current protection device
Yi-Hsuan Lee, Taichung (TW); Pin Hsuan Li, Hsinchu (TW); and Yi-An Sha, Xindian (TW)
Assigned to POLYTRONICS TECHNOLOGY CORP., Hsinchu (TW)
Filed by Polytronics Technology Corp., Hsinchu (TW)
Filed on Oct. 13, 2022, as Appl. No. 17/965,301.
Claims priority of application No. 111117175 (TW), filed on May 6, 2022.
Prior Publication US 2023/0361559 A1, Nov. 9, 2023
Int. Cl. H02H 9/02 (2006.01); H01C 7/02 (2006.01)
CPC H02H 9/026 (2013.01) [H01C 7/027 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An over-current protection device, comprising:
a resistor element having a first insulation layer, a first electrically conductive layer, a positive temperature coefficient (PTC) material layer, a second electrically conductive layer and a second insulation layer stacked sequentially from bottom to top, wherein the first insulation layer has a bottom surface and a first sidewall connected to the bottom surface, and the bottom surface has a first via and a second via penetrated therethrough;
an outer electrode having a first electrode and a second electrode disposed on the bottom surface, wherein the first electrode and the second electrode are electrically connected to the first electrically conductive layer through the first via and the second via, respectively, and the first electrode is electrically isolated from the second electrode, wherein:
the bottom surface of the first insulation layer has a long side and a short side, the first electrode is spaced apart from the short side by a first distance, and the first electrode is spaced apart from the long side by a second distance, wherein:
the first distance and the second distance range from 2 mil to 9 mil;
if the total length of the long side is calculated as 100%, the first distance ranges from 5% to 16% compared to the long side; and
if the total length of the short side is calculated as 100%, the second distance ranges from 9% to 27% compared to the short side; and
an encapsulation layer covering the first sidewall and extending to a part of the bottom surface of the first insulation layer, thereby forming a first perimeter on the bottom surface of the first insulation layer, wherein the first and second electrodes are located inside the first perimeter, and the encapsulation layer has a thickness ranging from 0.04 mm to 0.08 mm.