Organic matrix for acoustic reflector array

• US 5,883,457 A
• Filed: 04/24/1997
• Issued: 03/16/1999
• Est. Priority Date: 04/24/1997
• Status: Expired due to Term

• Current Assignee: Elo Touch Solutions, Inc.
• Original Assignee: Raychem Corporation (TE Connectivity Limited)
• Inventors: Rinde, James A., Mathews, Barry C.
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US08/839,995
• Time in Patent Office: 691 Days
• Field of Search: 310/313 R, 310/313 O
• US Class Current: 310/313.00D
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate

Abstract

A touch sensor system, including a substrate, capable of propagating surface acoustic waves; and a reflective array formed on said substrate, said reflective array having a plurality of reflective elements, each reflective element reflecting a portion of an incident surface acoustic wave. The reflective array is formed of an organic matrix. The organic matrix is preferably chemically bonded to the substrate, and is preferably a thermoset resin. The resulting reflective arrays are preferably stable under changes in moisture between 0% and 60% RH at temperatures between about 0°-50° C. The organic matrix can also be used in a humidity or chemical sensor.

Claims

1. A touch sensor system, comprising:

(a) a substrate capable of propagating acoustic waves; and

(b) a reflective array formed on said substrate and having a plurality of reflective elements, each reflective element reflecting a portion of an incident acoustic wave, said reflective array comprising an organic matrix, said organic matrix, after formation, being chemically bonded to said substrate.

2. A touch sensor system according to claim 1, wherein said organic matrix comprises a curable resin.

3. A touch sensor system according to claim 1, wherein said organic matrix comprises a thermally curable resin.

4. A touch sensor system according to claim 1, wherein said organic matrix comprises a thermally curable resin having a thermal cure initiation temperature below about 250°

C.

5. A touchsensor system according to claim 1, wherein said organic matrix comprises a UV light curable resin.

6. A touch sensor system according to claim 1, wherein said organic matrix comprises an epoxy resin.

7. A touch sensor system according to claim 1, wherein said organic matrix comprises a polymer including a curable composition selected from the group consisting of epoxy resin, cyanate ester resin, polyester resin, phenolic resin, bismaleimide resin, and combinations thereof.

8. A touch sensor system according to claim 1, wherein said organic matrix comprises a polymer having a glass transition temperature above about 120°

C.

9. A touch sensor system according to claim 1, wherein said organic matrix comprises:

(a) a polymer resin having a functionality of greater than about 1.7, including one or more compositions having functional groups selected the group consisting of epoxy, cyanate ester, polyester, phenolic, and bismaleimide;

(b) a thermoset curing agent, capable of initiating cure of said resin at a temperature below about 250°

C.; and

(c) a silane composition having a silane functional group and an additional functional group capable, of covalently binding said polymer resin.

10. A touch sensor system according to claim 9, further comprising a surfactant, capable of wetting glass.

11. A touch sensor system according to claim 1, wherein said reflective elements further comprise a dense filler dispersed in said organic matrix.

12. A touch sensor system according to claim 11, wherein said dense filler is selected from the group consisting of powdered tungsten, tungsten trioxide, tungsten carbide, calcium carbonate, lead oxide, zinc oxide, barium sulfate, zinc sulfide, silicon dioxide, and combinations thereof.

13. A touch sensor according to claim 11, wherein said dense filler has a density greater than about 4.0 g/cm³.

14. A touch sensor system according to claim 11, wherein said dense filler comprises a coprecipitate of barium sulfate and zinc sulfide.

15. A touch sensor system according to claim 11, wherein said dense filler comprises a tungsten-containing composition.

16. A touch sensor according to claim 1, wherein said substrate comprises a siliceous composition, wherein said siliceous composition is treated with a silane composition prior to formation of said reflective array thereon.

17. The touch sensor according to claim 1, wherein said substrate comprises a siliceous composition and said organic matrix further comprises a silane composition.

18. A touch sensor according to claim 1, wherein said organic matrix is printed on said substrate.

19. A touch sensor according to claim 1, wherein said substrate comprises tempered glass.

20. A touch sensor according to claim 1, wherein said substrate is the faceplate of a cathode ray tube.

21. A touch sensor according to claim 1, further comprising:

(i) a transducer for receiving an acoustic wave from said substrate;

(ii) each element of said reflecting array reflecting a portion of said acoustic wave toward said transducer, such that a substantially corresponding signal is generated by said transducer under changes in moisture between 10% and 60% RH at a temperature of 50°

C.

22. A touch sensor system, comprising:

(a) a substrate, capable of propagating acoustic waves; and

(b) a reflective array formed on said substrate, said reflective array having a plurality of reflective elements, each reflective element reflecting a portion of an incident surface acoustic wave, said reflective array comprising an organic matrix, said organic matrix being a thermoset polymer curing at a temperature above about 50°

C. and below about 250°

C.