Surface-mount fuse having a substrate with surfaces and a metal strip attached to the substrate using layer of adhesive material

• US 5,699,032 A
• Filed: 06/07/1996
• Issued: 12/16/1997
• Est. Priority Date: 06/07/1996
• Status: Expired due to Fees

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Littelfuse Incorporated
• Inventors: Rybka, Matthew Michael, Harris, Edwin James IV, Ulm, Steven Francis Jr.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Gandhi, Jayprakash N.
• Application Number:
  US08/660,498
• Time in Patent Office: 557 Days
• Field of Search: 337/152, 337/227, 337/228, 337/297, 337/404, 337/405, 29/623
• US Class Current: 337/297
• 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 85/143 Electrical contacts; Fastening fusible members to such contacts
• CPC Class Codes: H05K 3/3421 Leaded components
• CPC Class Codes: H05K 3/3426 characterised by the leads
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A surface-mount fuse for protecting a circuit, includes a substrate having first and second surfaces, each surface having first, second, third, and forth ends, the substrate also having first, second, third, and fourth sides. The fuse also includes a metal strip evenly attached to the first surface of the substrate with a layer of adhesive material, the layer of adhesive material being disposed between the metal strip and the first surface of the substrate, the metal strip having a first connection region, a second connection region, and a non-linear fuse link therebetween. The fuse further includes first and second wire leads aligned substantially with and along the first and second connection regions, respectively, the first wire lead being conductively connected to the first connection region and horizontally projecting away from the first connection region, the second wire lead being conductively connected to the second connection region and horizontally projecting away from the second connection region, for connecting the fuse to the remainder of the circuit. The layer of adhesive material can include a polymeric material therein. One alternative for the wire leads can include clip leads or other terminal leads. The fuse also includes a protective layer disposed on the fuse link, the protective layer being in contact with and surrounding the upper and side surfaces of the fuse link of the metal strip. A method of making the same is also disclosed herein.

Claims

1. A surface-mount fuse for protecting a circuit including the fuse comprising:

a substrate having first and second surfaces, each surface having first, second, third, and forth ends, the substrate also having first, second, third, and fourth sides;

a metal strip evenly attached to the first surface of the substrate with a layer of adhesive material, the layer of adhesive material being disposed between the metal strip and the first surface of the substrate, the metal strip having a first connection region, a second connection region, and a fuse link therebetween having an upper surface and a side surface, the first connection region being disposed along substantially the full length of the first end of the first surface of the substrate, the second connection region being disposed along substantially the full length of the second end of the first surface of the substrate; and

,

first and second wire leads aligned substantially with and along the first and second connection regions, respectively, the first wire lead being conductively connected to the first connection region and horizontally projecting away from the first connection region, the second wire lead being conductively connected to the second connection region and horizontally projecting away from the second connection region, for connecting the fuse to the remainder of the circuit.

2. The surface-mount fuse of claim 1 wherein a protective layer is disposed on the fuse link, the protective layer being in contact with and surrounding the upper and side surfaces of the fuse link of the metal strip.

3. The surface-mount fuse of claim 2 wherein the protective layer is also in contact with at least a fraction of the first and second connection regions of the metal strip.

4. The surface-mount fuse of claim 2, wherein said protective layer is made of a polymeric material.

5. The surface-mount fuse of claim 2, wherein the protective layer is made of a polyurethane material.

6. The surface-mount fuse of claim 1, wherein the substrate is made of an FR-4 material.

7. The surface-mount fuse of claim 1, wherein the substrate is made of a melamine based composition.

8. The surface-mount fuse of claim 2, wherein the protective layer is clear and colorless.

9. The surface-mount fuse of claim 2, wherein the protective layer is clear and colored.

10. The surface-mount fuse of claim 2, wherein a solder material is disposed between the first and second wire leads and the first and second connection regions, respectively, of the metal strip, for connecting the first and second wire leads to the first and second connection regions.

11. The surface-mount fuse of claim 1, wherein the metal strip is made from a zinc alloy.

12. The surface-mount fuse of claim 1, wherein the metal strip is made from a sheet of zinc foil.

13. A surface-mount fuse for protecting a circuit including the fuse comprising:

a substrate having first and second surfaces, each surface having first, second, third, and forth ends, the substrate also having first, second, third, and fourth sides;

a metal strip evenly attached to the first surface of the substrate with a layer of polymeric material, the layer of polymeric material having first and second surfaces each respectively having an adhesive material attached thereto, the layer of polymeric material being disposed between the metal strip and the first surface of the substrate, the adhesive material on the first surface of the layer of polymeric material connecting the substrate to the first surface of the layer of polymeric material, and the adhesive material on the second surface of the layer of polymeric material connecting the metal strip to the second surface of the layer of polymeric material, wherein the metal strip has a first connection region, a second connection region, and a fuse link therebetween having an upper surface and a side surface, the first connection region being disposed along substantially the full length of the first end of the first surface of the substrate, the second connection region being disposed along substantially the full length of the second end of the first surface of the substrate;

a first terminal lead conductively connected to the first connection region and projecting away from the first connection region; and

,

a second terminal lead being conductively connected to the second connection region and projecting away from the second connection region, the first and second terminal leads connecting the fuse to the remainder of the circuit.

14. The surface-mount fuse of claim 13 wherein a protective layer is disposed on the fuse link, the protective layer being in contact with and surrounding the upper and side surfaces of the fuse link of the metal strip.

15. The surface-mount fuse of claim 14 wherein the protective layer is also in contact with at least a fraction of the first and second connection regions of the metal strip.

16. The surface-mount fuse of claim 14, wherein said protective layer is made of a polymeric material.

17. The surface-mount fuse of claim 14, wherein the protective layer is made of a polyurethane material.

18. The surface-mount fuse of claim 13, wherein the substrate is made of an FR-4 material.

19. The surface-mount fuse of claim 13, wherein the substrate is made of a melamine based composition.

20. The surface-mount fuse of claim 14, wherein the protective layer is clear and colorless.

21. The surface-mount fuse of claim 14, wherein the protective layer is clear and colored.

22. The surface-mount fuse of claim 14, wherein a solder material is disposed between the first and second terminal leads and the first and second connection regions, respectively, of the metal strip, for connecting the first and second terminal leads to the first and second connection regions.

23. The surface-mount fuse of claim 13, wherein the metal strip is made from a zinc alloy.

24. The surface-mount fuse of claim 13, wherein the metal strip is made from a sheet of zinc foil.

25. The surface-mount fuse of claim 13, wherein the layer of polymeric material is a polyamide.

26. A surface-mount fuse for protecting a circuit including the fuse comprising:

a substrate having first and second surfaces, each surface having first, second, third, and forth ends, the substrate also having first, second, third, and fourth sides;

a metal strip evenly attached to the first surface of the substrate with a layer of adhesive material, the layer of adhesive material being disposed between metal strip and the first surface of the substrate, the metal strip having a first connection region, a second connection region, and a fuse link therebetween having an upper surface and a side surface, the first connection region being disposed along substantially the full length of the first end of the first surface of the substrate, the second connection region being disposed along substantially the full length of the second end of the first surface of the substrate;

a first clip lead having at least one clip, each clip of the first clip lead having a mounting portion and a wrap-around portion, the wrap-around portion of each clip being aligned generally along the first connection region and first side of the substrate, and being conductively connected to the first connection region, wherein the wrap-around portion of each clip fastens the first clip lead to the substrate and first connection region, wherein the mounting portion of the first clip lead projects away from the first connection region; and

,

a second clip lead having at least one clip, each clip of the second clip lead having a mounting portion and a wrap-around portion, the wrap-around portion of each clip being aligned generally along the second connection region and second side of the substrate, and being conductively connected to the second connection region, wherein the wrap-around portion of each clip fastens the second clip lead to the substrate and second connection region, wherein the mounting portion of the second clip lead projects away from the second connection region, the first and second clip leads connecting the fuse to the remainder of the circuit.

27. The surface-mount fuse of claim 26 wherein a protective layer is disposed on the fuse link, the protective layer being in contact with and surrounding the upper and side surfaces of the fuse link of the metal strip.

28. The surface-mount fuse of claim 27 wherein the protective layer is also in contact with at least a fraction of the first and second connection regions of the metal strip.

29. The surface-mount fuse of claim 27, wherein said protective layer is made of a polymeric material.

30. The surface-mount fuse of claim 27, wherein the protective layer is made of a polyurethane material.

31. The surface-mount fuse of claim 26, wherein the substrate is made of an FR-4 material.

32. The surface-mount fuse of claim 26, wherein the substrate is made of a melamine based composition.

33. The surface-mount fuse of claim 27, wherein the protective layer is clear and colorless.

34. The surface-mount fuse of claim 27, wherein the protective layer is clear and colored.

35. The surface-mount fuse of claim 26, wherein a solder material is disposed between the first and second clip leads and the first and second connection regions, respectively, of the metal strip, for conductively connecting the first and second clip leads to the first and second connection regions.

36. The surface-mount fuse of claim 26, wherein the metal strip is made from a zinc alloy.

37. The surface-mount fuse of claim 26, wherein the metal strip is made from a sheet of zinc foil.

38. A surface-mount fuse for protecting a circuit including the fuse comprising:

a substrate having first and second surfaces, each surface having first, second, third, and forth ends, the substrate also having first, second, third, and fourth sides;

a metal strip evenly attached to the first surface of the substrate with a layer of polymeric material, the layer of polymeric material having first and second surfaces each respectively having an adhesive material attached thereto, the layer of polymeric material being disposed between the metal strip and the first surface of the substrate, the adhesive material on the first surface of the layer of polymeric material connecting the substrate to the first surface of the layer of polymeric material, and the adhesive material on the second surface of the layer of polymeric material connecting the metal strip to second surface of the layer of polymeric material, wherein the metal strip has a first connection region, a second connection region, and a fuse link therebetween having an upper surface and a side surface, the first connection region being disposed along substantially the full length of the first end of the first surface of the substrate, the second connection region being disposed along substantially the full length of the second end of the first surface of the substrate;

a first terminal lead conductively connected to the first connection region; and

,

a second terminal lead being conductively connected to the second connection region, the first and second terminal leads connecting the fuse to the remainder of the circuit.