Patent US4862134A successfully refreshed from Google Patents.
US4862134A
Expired / Lapsed
US
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Electrical fuse and method for its production
Assignee: Wickmann Werke GmbH
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Filing: 1988-07-19
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Granted: 1989-08-29
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Expires: 2008-07-19
Abstract
Abstract An electrical fuse comprises a fusible conductor welded or bonded onto separated contact surfaces. The fusible conductor is coated with a metal, selected solely for optimum welding or bonding to contact zones of the contact surfaces. The metallic coating of the fusible conductor is then removed at the fusible portion of the coated fusible conductor by etching after the fusible conductor is welded or bonded to the contact surfaces the contact zones surrounding the point of contact protected by a resin cover resistant to the etchant. The electrical characteristic of the fuse is thus determined solely by the core wire and its properties. The resin cover in the contact zones is preserved between the fusible conductor and each contact surface for improved safety against cracks or micro-cracks and their possible adverse effects.
Inventors
- 👤 Karl Poerschke
- 👤 Klaus Stark
- 👤 Bernd Frochte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:10
CPC Classifications
H; H01; H01H; H01H85/00; H01H85/02; H01H85/04; H01H85/041; H01H85/0411; H01H69/00; H01H69/02; H01H85/05; H01H85/143; H10; H10W; H10W72/00; H10W72/01; H10W72/015; H10W72/01515; H10W72/071; H10W72/075; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49107
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
62 words
An electrical fuse comprising: two conductors having contact surfaces; and a fusible conductor welded or bonded onto the contact surfaces; the fusible conductor being completely coated by a coating; the welding or bonding forming contact zones between the fusible conductor and the contact surfaces; and the complete coating existing within the contact zones and within areas immediately adjacent to the contact zones.
Claim 2
Dependent Claim
62 words
An electrical fuse comprising: two conductors having contact surfaces; and a fusible conductor welded or bonded onto the contact surfaces; the fusible conductor being completely coated by a coating; the welding or bonding forming contact zones between the fusible conductor and the contact surfaces; and the complete coating existing within the contact zones and within areas immediately adjacent to the contact zones.
Claim 3
Dependent Claim
13 words
The electrical fuse according to claim 1 wherein the contact surfaces are plated.
Claim 4
Dependent Claim
21 words
The electrical fuse according to claim 1 wherein the contact zone and adjacent areas are covered by an etchant protective layer.
Claim 5
Dependent Claim
21 words
The electrical fuse according to claim 2 wherein the contact zone and adjacent areas are covered by an etchant protective layer.
Claim 6
Dependent Claim
22 words
The electrical fuse according to claim 1 wherein the material of the coating is similar to the material of the contact surfaces.
Claim 7
Dependent Claim
21 words
The electrical fuse according to claim 2 wherein the material of the coating is similar to the material of the plating.
Claim 8
Dependent Claim
41 words
The electrical fuse according to claim 1 wherein the contact surfaces are supported by a substrate, the substrate having soldering surfaces on the side opposite from the contact surfaces, each contact surface having a through-connection to the corresponding opposite soldering surface.
Claim 9
Dependent Claim
13 words
The electrical fuse according to claim 7 wherein the contact surfaces are plated.
Claim 10
Dependent Claim
14 words
The electrical fuse according to claim 7 wherein the substrate is a ceramic substrate.
Claim 11
Dependent Claim
20 words
The electrical fuse according to claim 9 wherein the contact surfaces and/or the soldering surfaces are printed onto the substrate.
Claim 12
Dependent Claim
24 words
The electrical fuse according to claim 7 wherein the fusible conductor is covered by a plastic hood being thermally welded directly onto the substrate.
Claim 13
Dependent Claim
22 words
The electrical fuse according to claim 1 wherein the contact surfaces are attached to a substrate, the substrate having laterally metallized edges.
Claim 14
Dependent Claim
15 words
The electrical fuse according to claim 12 wherein ' the substrate is a ceramic substrate.
Claim 15
Dependent Claim
16 words
The electrical fuse according to claim 12 wherein the contact surfaces are printed onto the substrate.
Claim 16
Dependent Claim
24 words
The electrical fuse according to claim 12 wherein the fusible conductor is covered by a plastic hood being thermally welded directly onto the substrate.
Claim 17
Dependent Claim
68 words
A method for the manufacture of the electrical fuse of claim 1 wherein the completely coated fusible conductor is welded or bonded onto the contact surfaces thus creating contact zones, the contact zones and adjacent areas to the contact zones are covered by an etchant protective layer and the coating is etched away from the unprotected portion of the fusible conductor by an etchant forming a fusible area.
Claim 18
Dependent Claim
16 words
The method according to claim 16 wherein the etchant protective layer consists of an epoxy resin.
Claim 19
Dependent Claim
21 words
The method according to claim 16 wherein the contact surfaces are plated before the welding or bonding of the fusible conductor.
Claim 20
Dependent Claim
39 words
The method according to claim 18 wherein the coating of the fusible conductor and the plating of the contact surfaces consists essentially of aluminum or an aluminum alloy and wherein the etchant is soda lye or other suitable etchant.
Claim 21
Dependent Claim
42 words
The method according to claim 18 wherein the coating of the fusible conductor and the plating of the contact surfaces consist essentially of silver, the fusible conductor consists essentially of gold and wherein the etchant is nitric acid or other suitable etchant.
Claim 22
Dependent Claim
25 words
The method according to claim 16 wherein the overall thickness of the coated fusible conductor is maintained constant for various core wires having varying diameters.
Claim 23
Dependent Claim
77 words
The method according to claim 16 wherein the contact surfaces are arranged in pairs on the substrate and then at least one endless fusible conductor is welded or bonded onto each contact surface of each pair, a substrate fuse section carrying one pair of contact surfaces and at least one fusible conductor, the substrate fuse sections being removed from the substrate one after the other after the etching step by separating the substrate into substrate fuse sections.
Claim 24
Dependent Claim
57 words
The method according to claim 22 wherein at least one hole or an oblong hole is formed on the substrate at each border between two adjacent single substrate fuse sections carrying one pair of contact surfaces, the at least one hole or the oblong hole being metallized for providing an edge metallization and/or a graded break line.
Claim 25
Dependent Claim
38 words
The method according to claim 22 wherein each substrate fuse section supporting a pair of contact surfaces is provided on the opposite side with a pair of soldering surfaces, the soldering surfaces being through-connected to the contact surfaces.
Claim 26
Dependent Claim
54 words
The method according to claim 22 wherein the substrate forms a linear strip with pairs of contact surfaces one beside the other and wherein the lateral longitudinal edges are metallized before the welding or bonding of the fusible conductor, the metallization being in electrical conductive contact with each contact surface of the respective side.
Claim 27
Dependent Claim
26 words
The method according to claim 22 wherein each pair of contact surfaces is covered by a plastic lid which is firmly welded directly onto the substrate.
Claim 28
Dependent Claim
67 words
The method according to claim 22 wherein the number of plastic lids is equal to the number of the single substrate sections carrying one pair of contact surfaces, the plastic lids being connected to each other in the configuration of the single substrate sections and wherein each plastic lid is separated from the adjacent plastic lids during the separation together with separation of the single substrate sections.
Claim 29
Dependent Claim
69 words
The method according to claim 26 wherein the number of plastic lids is equal to the number of the single substrate sections carrying one pair of contact surfaces, the plastic lids being connected to each other in the configuration of the single substrate sections and wherein each plastic lid is separated from the adjacent plastic lids during the separation step together with separation of the single substrate fuse sections.
Claim 30
Dependent Claim
52 words
An electrical fuse comprising: two conductors on a substrate having contact surfaces; a fusible conductor welded or bonded onto the contact surfaces, the welding or bonding forming contact zones; the substrate having soldering surfaces on the side opposite the contact surfaces; and through-connections connecting each contact surface to corresponding opposite soldering surfaces.
Claim 31
Dependent Claim
52 words
An electrical fuse comprising: two conductors on a substrate having contact surfaces; a fusible conductor welded or bonded onto the contact surfaces, the welding or bonding forming contact zones; the substrate having soldering surfaces on the side opposite the contact surfaces; and through-connections connecting each contact surface to corresponding opposite soldering surfaces.
Claim 32
Dependent Claim
23 words
The electrical fuse of claim 29, the fusible conductor having a metallic coating selected for optimum welding or bonding to the contact surfaces.
References Cited (Backward Citations)
US4037318A
Cited
US4771260A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |