Circuit protection device

Patent metadata

Field	Value
Publication number	US-9401257-B2
Application number	US-201313975728-A
Country	US
Kind code	B2
Filing date	Aug 26, 2013
Priority date	Nov 24, 2009
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

A circuit protection device includes a conductive layer which is connected to first and second terminals. A spring is electrically connected to the first and second terminals. When an over-voltage or over-temperature condition occurs within a charging circuit, one or more heat generating resistive elements melts material associated with one or more of the ends of the spring thereby releasing the spring to create an open circuit.

First claim

What is claimed is:

1. A circuit protection device, comprising:
a substrate;
a conducting layer disposed on said substrate, said conducting layer having a first conducting path and a second conducting path;
a first resistive element disposed on a first portion of the first conducting path and a first portion of the second conducting path;
a second resistive element disposed on a second portion of the first conducting path and a second portion of the second conducting path;
a dielectric layer disposed on the first and second resistive elements;
a first conducting pad disposed on said dielectric layer and above said first resistive element, the first conducting pad connected to a first terminal;
a third conducting pad disposed on said dielectric layer and above said second resistive element, the second conducting pad connected to a second terminal, the first conducting path connected to a third terminal;
a diffusion layer disposed over said first and second conducting pads; and
a glass layer disposed over the diffusion layer, wherein when an abnormal circuit condition occurs heat is generated by the first and second resistive elements which causes a portion of the diffusion layer to diffuse into the glass layer to create an open circuit between the first and second terminals.

2. The circuit protection device of claim 1 , further comprising a via formed through said dielectric layer and electrically connected to said second conducting path.

3. The circuit protection device of claim 1 , wherein the dielectric layer is glass having a desired thermal conductivity such that heat generated by the first and second resistive elements passes therethrough.

4. The circuit protection device of claim 1 , wherein the diffusion layer is a thin film metallic layer.

5. The circuit protection device of claim 1 , further comprising a control circuit connected to the third terminal, the control circuit configured to draw current from the diffusion layer during the abnormal circuit condition.

6. The circuit protection device of claim 2 , further comprising a second conducting pad disposed on said dielectric layer and electrically connected to said second conducting path through said via and connected to said third terminal.

7. The circuit protection device of claim 4 , wherein the diffusion layer is a thin film of gold.

Assignees

• Dietsch G Todd
• Spaldon-Stewart Olga
• Whitney Stephen
• Littelfuse Inc

Inventors

• Dietsch G Todd
• Spaldon-Stewart Olga
• Whitney Stephen

Classifications

• H01H85/0417 Primary

  with parallel side contacts · CPC title

• H01H85/0052

  Fusible element and series heating means or series heat dams · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01H85/0039

  Means for influencing the rupture process of the fusible element · CPC title

• H01H85/0241 Primary

  Structural association of a fuse and another component or apparatus (switches with built-in fuses H01H9/10, spark-gap arresters H01H85/44, transformers and inductances H01F27/402, capacitors H01G2/14, lamps H01K1/66, semiconductors H10W20/493 or H10W42/80) · CPC title