US 5,726,621 AGranted

Ceramic chip fuses with multiple current carrying elements and a method for making the same

AssigneeCooper Industries, Inc.

InventorsStephen Whitney, Keith Spalding, Joan Winnett, Varinder Kalra

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Abstract

A subminiature circuit protector includes a plurality of layers of ceramic material in a laminate structure, each layer bearing a fuse element. The ends of laminate structure are coated with electrically conductive end terminations. The fuse elements of the layers may be connected in parallel, with fuse elements on each layer connecting to both end terminations, or interconnected in series from one end termination to the other. Each of the fuse elements of the individual layers may comprise two or more individual fuse elements connected in series or in parallel. A method for manufacturing the circuit protector in accordance with the invention includes the steps of printing a multiplicity of fuse elements on a plurality of substrates, stacking the substrates to form a laminate structure, cutting the laminate into individual units, and coating the opposite ends of the units with electrically conductive material to form end terminations.

Claims26

Dependent claims

A chip fuse, comprising:

a plurality of substrate layers of ceramic material each having an upper surface, said substrate layers being arranged in a stack having at least an uppermost and lowermost substrate layer;
a fuse element of electrically conductive material disposed on the upper surface of two or more of said substrate layers, each of said fuse elements comprising a pad of electrically conductive material disposed at each of a first and a second end portion of said first substrate, and at least one fusible element electrically connecting said pads;
a cover of ceramic material covering an upper surface of the uppermost substrate layer, wherein said substrate layers and cover form a laminate structure having first and second end portions;
and
means for electrically interconnecting said fuse elements of the plurality of substrate layers, wherein
said means for electrically interconnecting the fuse elements comprises a plurality of conductors each disposed in one of a plurality of holes extending through the substrate layers in predetermined locations to electrically connect the fuse elements of adjacent substrate layers,
said means for electrically connecting at least an uppermost fuse element to the end termination at the first end portion comprises a conductor disposed in a hole extending from a pad on the uppermost substrate layer through the uppermost substrate layer and intervening substrate layers to the end termination;
and
said means for electrically connecting said lowermost fuse element to the end termination at the second end portion comprises a conductor disposed in a hole extending from a pad on said lowermost substrate layer through the lowermost substrate layer to the end termination at the second portion.

6 more elements

A chip fuse, comprising:

a first substrate of ceramic material having an upper surface;
a first fuse element of electrically conductive material disposed on the upper surface of the first substrate;
a second substrate of ceramic material having an upper surface and disposed on said first substrate;
a second fuse element of electrically conductive material disposed on the upper surface of the second substrate;
a cover of ceramic material covering the upper surface of the second substrate, wherein said first substrate, second substrate and cover form a chip having first and second end portions;
and
means for electrically connecting the first fuse element and the second fuse element.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/514,088Filed 11 Aug 1995 · continuation in part
Priority: 12 Sep 1994
Granted: 10 Mar 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H01H 85/0411
Characterised by the type: miniature fuses
H01H 69/02
Apparatus or processes for the manufacture of emergency protective devices: manufacture of fuses
H01H 69/022
Manufacture of fuses: of printed circuit fuses
H01H 85/0418
Cartridge type: with ferrule type end contacts