IN-MOLDED CAPACITIVE SWITCH

• US 20080257706A1
• Filed: 04/18/2008
• Published: 10/23/2008
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: E2IP Technologies Incorporated
• Original Assignee: T-Ink Inc. (Winnick & Co., Inc.)
• Inventors: Haag, Ronald H.
• Granted Patent: US 8,514,545 B2
• Time in Patent Office: Days
• US Class Current: 200/600
• CPC Class Codes: B29C 45/14655 connected to or mounted on a carrier, e.g. lead frame
• CPC Class Codes: B29C 45/14811 Multilayered articles B29C45/14827 takes precedence
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/96019 using conductive paint
• CPC Class Codes: H03K 2217/960755 Constructional details of capacitive touch and proximity switches
• CPC Class Codes: H03K 2217/960785 with illumination
• CPC Class Codes: H03K 2217/96079 using a single or more light guides
• CPC Class Codes: H05K 2203/1316 Moulded encapsulation of mounted components
• CPC Class Codes: H05K 3/0014 Shaping of the substrate, e.g. by moulding
• CPC Class Codes: H05K 3/12 using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/30 Assembling printed circuits with electric components, e.g. with resistor
• CPC Class Codes: Y10T 29/49105 Switch making
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

An article of manufacture having an in-molded capacitive switch and method of making the same are shown and described. In one disclosed method, a conductive ink sensing zone is printed on a film. The film is formed to a desired shape and put in an injection mold. A molten plastic material is introduced into the injection mold to form a rigid structure that retains the film.

Claims

1. An article of manufacture having an in-molded capacitive switch, comprising:

a film having a front surface and a back surface and at least one conductive ink sensing zone printed on the back surface; and

a plastic support structure, wherein the back surface of the film faces the plastic support structure, and the film is secured to the plastic support structure.

2. The article of manufacture of claim 1, wherein at least a portion of the front surface of the film is exposed.

3. The article of manufacture of claim 1, wherein the at least one conductive ink sensing zone is not exposed.

4. The article of manufacture of claim 1, wherein the back surface of the film is not exposed.

5. The article of manufacture of claim 1, further comprising at least one connector electrically connected to the at least one conductive ink sensing zone, wherein a portion of the at least one connector projects away from the plastic support structure.

6. The article of manufacture of claim 1, comprising at least one electrical connector molded into the plastic support structure and electrically connected to the at least one conductive ink sensing zone.

7. The article of manufacture of claim 5, wherein the film further comprises at least one printed ink electrode electrically connected to the at least one conductive ink sensing zone, and wherein the at least one connector is connected to the at least one printed ink electrode with a conductive adhesive.

8. The article of manufacture of claim 1, further comprising at least one light emitting diode molded into the plastic support structure such that when energy is applied to the diode, it emits light from the front surface of the film.

9. The article of manufacture of claim 1, further comprising indicia related to a function of the capacitive switch, wherein the indicia is printed on the back surface of the film and is visible on the front surface of the film.

10. A control device, comprising:

the article of manufacture of claim 1, wherein the at least one conductive ink sensing zone is electrically connected to a circuit that is operable to detect capacitance changes.

11. A method of making an article of manufacture having an in-molded capacitive switch, comprising:

providing a film having a front surface and a back surface;

printing a conductive ink sensing zone on the back surface of the film;

forming the film into a desired shape, thereby creating a formed film;

providing an injection mold having an interior;

disposing the formed film in the injection mold such that the conductive ink sensing zone faces into the interior of the mold; and

flowing molten plastic into the injection mold to create a plastic support structure attached to the film, thereby creating the article.

12. The method of claim 11, wherein in the disposing step, the conductive ink sensing zone is not in contact with a surface of the mold.

13. The method of claim 11, wherein the injection mold comprises a first mold half that is mateable with a second mold half, the step of disposing the formed film in an injection mold comprises disposing the formed film in the first mold half, and the method further comprises disposing at least one connector in the second mold half and mating the first mold half and the second mold half before the step of flowing molten plastic into the injection mold.

14. The method of claim 11, wherein the step of forming the film into a desired shape comprises vacuum thermoforming.

15. The method of claim 11, wherein the step of forming the film into a desired shape comprises high pressure forming.

16. The method of claim 11, wherein the step of flowing molten plastic into the mold causes molten plastic to flow over the back surface of the film.

17. The method of claim 11, further comprising removing the article from the mold, wherein at least a portion of the front surface of the film is exposed.

18. The method of claim 11, further comprising removing the article from the mold, wherein the at least one conductive ink sensing zone is not exposed.

19. The method of claim 11, further comprising removing the article from the mold, wherein the at last one conductive ink sensing zone faces the plastic support structure.

20. The method of claim 11, further comprising printing graphic indicia on the back surface of the film, wherein the graphic indicia are visible on the front surface of the film.

21. An electromagnetic shield, comprising:

a film having a conductive ink ground layer printed on a surface of said film; and

a plastic support structure, wherein the film is secured to the plastic support structure.

22. The electromagnetic shield of claim 21, wherein the surface of said film is the A-surface.

23. The electromagnetic shield of claim 21, wherein the surface of said film is the B-surface.

24. The electromagnetic shield of claim 21, wherein the film is molded within the plastic support structure.

25. The electromagnetic shield of claim 24, wherein some or all of the A-surface of said film is exposed.

26. A capacitive switch, comprising:

a film having a conductive ink sensing zone printed on a surface of said film; and

a plastic support structure, wherein the film is secured to the plastic support structure.

27. The capacitive switch of claim 26, wherein the surface of said film is the A-surface.

28. The capacitive switch of claim 26, wherein the surface of said film is the B-surface.

29. The capacitive switch of claim 26, further comprising a dielectric ink layer adjacent to said conductive ink sensing zone.

30. The capacitive switch of claim 29, further comprising a conductive ink ground layer adjacent to said dielectric ink layer, wherein the dielectric ink layer insulates said conductive ink ground layer from said conductive ink sensing zone.

31. The capacitive switch of claim 26, wherein the film is molded within the plastic support structure.

32. The capacitive switch of claim 31, wherein some or all of the A-surface of said film is exposed.