SOLDER INTERCONNECTIONS FOR FLAT CIRCUITS

• US 20040055784A1
• Filed: 02/20/2002
• Published: 03/25/2004
• Est. Priority Date: 02/20/2002
• Status: Active Grant

• Current Assignee: Molex Incorporated
• Original Assignee: Molex Incorporated
• Inventors: Joshi, Prashant P., Fuerst, Robert M.
• Granted Patent: US 6,794,580 B2
• Time in Patent Office: Days
• US Class Current: 174/254
• CPC Class Codes: B23K 1/0008 specially adapted for particular articles or work
• CPC Class Codes: B23K 2101/38 Conductors
• CPC Class Codes: H01R 12/61 connecting to flexible printed circuits, flat or ribbon cables or like structures
• CPC Class Codes: H01R 12/62 connecting to rigid printed circuits or like structures
• CPC Class Codes: H01R 4/024 comprising preapplied solder
• CPC Class Codes: H01R 43/0235 for applying solder H01R43/0228 takes precedence
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 3/281 by means of a preformed insulating foil H05K3/284 takes precedence
• CPC Class Codes: H05K 3/3473 Plating of solder
• CPC Class Codes: H05K 3/3489 Composition of fluxes; Methods of application thereof; Other methods of activating the contact surfaces
• CPC Class Codes: H05K 3/363 by soldering

Abstract

A system and method are provided for facilitating the interconnection of the conductors of a flat circuit. A flat circuit substrate is provided with a plurality of conductors thereon. A dielectric film on the substrate substantially covers the conductors. An opening is formed in the film to selectively expose the conductors. A layer of solder material is preapplied to the exposed conductors in the opening. Therefore, the opening can be juxtaposed with a mating conductor to facilitate interconnecting the conductors by an appropriate soldering process using the preapplied solder material.

Claims

1. A system for facilitating the interconnection of the conductors of a pair flat circuits, comprising:

a first flat circuit having a plurality of conductors covered by a dielectric film, with an opening in the film to selectively expose the conductors, and a layer of solder material on the exposed conductors in the opening; and

a second flat circuit having a plurality of conductors covered by a dielectric film, with an opening in the film to selectively expose the conductors, and a layer of solder material on the exposed conductors in the opening;

whereby said openings can be juxtaposed with the flat circuits overlapping each other to facilitate interconnecting the conductors of the two flat circuits by an appropriate soldering process using the preapplied solder material.

2. The system of claim 1 wherein the opening in the dielectric film of at least one of the flat circuits is located at a distal end of the circuit.

3. The system of claim 1 wherein the opening in the dielectric film of at least one of the flat circuits spans a width of the circuit spaced inwardly from a distal end thereof.

4. The system of claim 1 wherein the opening in the dielectric film of at least one of the flat circuits comprises a window surrounded by the film.

5. The system of claim 4, including a plurality of said windows in a predetermined pattern in the film.

6. The system of claim 1 wherein said solder material comprises a layer of solder covered by a layer of flux.

7. The system of claim 1 wherein at least one of said flat circuits comprises a flat flexible circuit.

8. The system of claim 7 wherein said flat flexible circuit includes a flat flexible substrate having the conductors and dielectric film laminated thereto.

9. A system for facilitating the interconnection of the conductors of a flat circuit, comprising:

a flat circuit substrate;

a plurality of conductors on the substrate;

a dielectric film on the substrate substantially covering the conductors, with an opening in the film to selectively expose at least one of the conductors; and

a layer of solder material on the exposed conductor in the opening,

whereby said opening can be juxtaposed with a mating conductor to facilitate interconnecting the conductors by an appropriate soldering process using the preapplied solder material.

10. The system of claim 9 wherein the opening in the dielectric film is located at a distal end of the circuit.

11. The system of claim 9 wherein the opening in the dielectric film spans a width of the circuit spaced from a distal end thereof.

12. The system of claim 9 wherein the opening in the dielectric film comprises a window surrounded by the film.

13. The system of claim 12, including a plurality of said windows in a predetermined pattern in the film.

14. The system of claim 9 wherein said solder material comprises a layer of solder covered by a layer of flux.

15. The system of claim 9 wherein said flat circuit substrate is flexible.

16. The system of claim 15 wherein said flat flexible circuit substrate comprises a second dielectric film.

17. A method of fabricating and interconnecting the conductors of a pair of flat circuits, comprising the steps of:

providing a first flat circuit having a plurality of conductors covered by a dielectric film;

forming an opening in the film to selectively expose at least some of the conductors;

applying a layer of solder material on the exposed conductors in the opening;

providing a second flat circuit having a plurality of conductors covered by a dielectric film;

forming an opening in the film of the second flat circuit to selectively expose at least some of the conductors thereof,

applying a layer of solder material on the exposed conductors of the second flat circuit in the opening thereof,

overlapping the flat circuits with the openings in the respective dielectric films thereof in juxtaposition; and

soldering the conductors of the second flat circuit through the juxtaposed openings using the preapplied solder material.

18. The method of claim 17 including forming the opening in the dielectric film of at least one of the flat circuits at a distal end of the circuit.

19. The method of claim 17 including forming the opening in the dielectric film of at least one of the flat circuits spanning a width of the circuit spaced inwardly from a distal end thereof.

20. The method of claim 17 including forming the opening in the dielectric film of at least one of the flat circuits as a window surrounded by the film.

21. The method of claim 20 including forming a plurality of said windows in a predetermined pattern in the film of the at least one flat circuit.

22. The method of claim 17 including providing said solder material with a layer of solder covered by a layer of flux.

23. The method of claim 17 including providing at least one of said flat circuits as a flat flexible circuit.

24. The method of claim 23 including providing said flat flexible circuit with a flat flexible substrate having the conductors and dielectric film laminated thereto.

25. A method of fabricating a flat circuit, comprising the steps of:

providing a flat circuit substrate with a plurality of conductors thereon and covered by a dielectric film;

forming an opening in the film to selectively expose at least some of the conductors;

applying a layer of solder material on the exposed conductors in the opening;

whereby said opening can be juxtaposed with a mating conductor to facilitate interconnecting the conductors by an appropriate soldering process using the preapplied solder material.

26. The system of claim 25 including forming the opening in the dielectric film at a distal end of the circuit.

27. The system of claim 25 including forming the opening in the dielectric film to span a width of the circuit spaced from a distal end thereof.

28. The system of claim 25 including forming the opening in the dielectric film as a window surrounded by the film.

29. The system of claim 28 including forming a plurality of said windows in a predetermined pattern in the film.

30. The system of claim 25 including providing said solder material with a layer of solder covered by a layer of flux.

31. The system of claim 25 including providing said flat circuit substrate as a flexible substrate.

32. The system of claim 31 including providing said flat flexible circuit substrate as a second dielectric film.