Encapsulated fuse having a conductive polymer and non-cured deoxidant

• US 5,777,540 A
• Filed: 01/29/1996
• Issued: 07/07/1998
• Est. Priority Date: 01/29/1996
• Status: Expired due to Fees

• Current Assignee: CTS Corporation
• Original Assignee: CTS Corporation
• Inventors: Hreha, Steven J., Hollinger, William A. Jr., Dedert, Ronald J.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Gandhi, Jayprakash N.
• Application Number:
  US08/592,907
• Time in Patent Office: 890 Days
• Field of Search: 337/4, 337/142, 337/160, 337/260, 337/268, 337/270, 337/290, 337/401, 257/665, 438/601
• US Class Current: 337/142
• CPC Class Codes: H01H 69/02 Manufacture of fuses
• CPC Class Codes: H01H 69/022 of printed circuit fuses
• CPC Class Codes: H01H 85/0411 Miniature fuses
• CPC Class Codes: H01H 85/046 Fuses formed as printed circuits
• CPC Class Codes: H01H 85/06 characterised by the fusible material H01H85/11 takes precedence
• CPC Class Codes: H01H 85/143 Electrical contacts; Fastening fusible members to such contacts
• CPC Class Codes: H01H 85/18 Casing fillings, e.g. powder

Abstract

A simplified method of manufacturing an electrothermal fuse includes the steps of screening conductive epoxy onto fuse link termination pads, placing a metal alloy fuse link into the conductive epoxy on the termination pads, curing the conductive epoxy, applying deoxidant, applying encapsulant, and curing the encapsulant. The resultant fuse of the preferred embodiment comprises a substrate, termination pads, conductive epoxy interconnects, a solder type fuse link, liquid deoxidant and encapsulant.

Claims

1. An electrothermal fusing circuit comprising:

two terminations;

a meltable fuse link extending between said two terminations;

a conductive polymer interconnecting said two terminations to said meltable fuse link;

a non-cured deoxidant protecting said fuse link from oxidation;

an encapsulant, said encapsulant encapsulating said fuse link and said non-cured deoxidant.

2. The electrothermal fuse of claim 1 further comprising peripheral electrical devices, said peripheral electrical devices also encapsulated by said encapsulant.

3. The electrothermal fusing circuit of claim 1 wherein said meltable fuse link is comprised by a solder alloy.

4. The electrothermal fusing circuit of claim 3 wherein said solder alloy is a tin-lead eutectic.

5. The electrothermal fusing circuit of claim 1 wherein said conductive polymer is comprised by a silver-filled epoxy.

6. The electrothermal fusing circuit of claim 1 wherein said non-cured deoxidant is a liquid.